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Hidden Depths
The Origins of Human
Connection
Penny Spikins
Published by
White Rose University Press
(Universities of Leeds, Sheeld and York)
University of York,
Heslington, York, UK, YO10 5DD
https://universitypress.whiterose.ac.uk
Hidden Depths: the origins of human connection
Text © Penny Spikins 2022
First published 2022
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Contents
Acknowledgements ix
Foreword xi
Introduction 1
Aims 1
Challenges 4
Structure 9
References 11
Part 1: Compassion, Generosity and Trust 15
Chapter 1. The Evolutionary Basis for Human Empathy,
Compassion and Generosity 17
Abstract 17
Introduction 19
How do we respond to another’s distress? The neurobiology
of compassion 21
Empathy 21
From empathy to constructive help 24
Growing into our empathy: progressively complex
responses through childhood development 25
Disentangling evolutionary mechanisms 31
Why be kind? The evolutionary advantages of compassionate
helping behaviours 32
Animal comparisons: stages in the evolution of human empathy,
compassion and generosity 36
Comparing non-human apes and humans: emotional
capacities and helping behaviours of human ancestors
7 to 8 million years ago 37
Cognitive empathy 43
Aective empathy 44
Evolutionary pressures on emotional motivations 50
Implications for the evolution of human empathy, compassion
and generosity 55
Conclusions 57
Key points 58
References 60
Chapter 2. Material Evidence: caring for adult vulnerabilities 71
Abstract 71
Introduction 73
Archaeological evidence for the emergence of human compassion
and generosity 76
Before two million years ago: earliest beginnings? 77
Doubts about implications? 79
The nature of helping in australopithecines 81
After two million years ago: the emergence of ‘humans’ 82
Evidence for care of the ill and injured 84
Care as part of increasing interdependence 89
After half a million years ago: later periods of human evolution 91
To what extent can archaeological evidence be used to infer key
changes in emotional connections and capacities for compassion? 99
Other realms of material evidence for helping those in need 104
Implications: a long evolutionary history of human vulnerability,
compassion and interdependence 106
Conclusions 111
Key points 112
References 114
Chapter 3. Trust, Emotional Commitments and Reputation 129
Abstract 129
Introduction 131
Trust and a sensitivity to emotional motivations in human
evolutionary origins 133
Our human drive to understand the emotions behind
other people’s actions 133
Why early human interdependence made a good reputation matter 136
Trust, emotional commitments and the price to pay for caring
about reputation 141
The signicance of trust, emotional commitments and a concern
with reputation to key issues in human origins 142
Being kind rather than being cunning 142
Reecting on the cultural transmission of knowledge 144
Reecting on the inuence of emotional reputation on attention
to the aesthetics of artefact form 146
Reecting on a sensitivity to emotional motivations
and the integration of dierent minds 150
Further questions 156
Wired for trust? 158
Conclusions 158
Key points 159
References 160
Part 2: Tolerance, Sensitivity and Emotional Vulnerability 169
Chapter 4. The Evolutionary Basis for Human
Tolerance – Physiological Responses 171
Abstract 171
Introduction 173
Intergroup tolerance in human evolutionary past 174
The evolutionary background to human physiological reactions
to unfamiliar people 178
Neurobiology, emotional responses and social behaviour 181
The physiology of changes in avoidance behaviour – how
changes in hormones might make us less competitive or fearful 184
Competition and aggression – the role of androgens 184
Fear, stress reactivity and cortisol 190
The physiology of changes in approach behaviour – how
changes in hormones might make us more ‘friendly’ 193
Goal seeking exploration and novelty – the inuence
of dopamine 193
Bonding hormones 198
Selective pressures on human tolerance 202
Conclusions 203
Key points 204
References 205
Chapter 5. The Evolutionary Basis for Human Tolerance:
human ‘self-domestication’? 221
Abstract 221
Introduction 223
Human self-domestication? 225
Implications 229
The advantages of increasing tolerance 230
The constraints and disadvantages of increasing tolerance 234
Compensatory mechanisms 239
Conclusions 242
Key points 243
References 244
Chapter 6. Comforting Things: cherished possessions as
sources of social comfort and security, from the Palaeolithic
to the present 255
Abstract 255
Introduction 258
The appearance of widespread non-functional objects
in the archaeological record 260
New emotional relationships to objects? 264
Compensatory attachments to objects in childhood 264
Compensatory attachments to objects in adulthood 268
Are there common forms or features to cherished
personal objects? 271
Cultural variations 272
Art in search of empathy – reappraising the proliferation
of symbolic objects 274
Conclusions 281
Key points 282
References 284
Chapter 7. In The Company of Wolves: compensatory
attachments and the human-dog bond 295
Abstract 295
Introduction 298
Dogs in recent ethnographic contexts 300
Dogs as a form of technology 301
Dogs as playing a role in emotional wellbeing 304
Dogs as sources of emotional support in modern
industrialised contexts 310
Reappraising the domestication of wolves from the perspective
of emotional vulnerabilities 311
Archaeological evidence 312
Similar evolutionary pathways in dogs and humans 319
How did wolves become close to humans? 324
Conclusions 327
Key points 328
References 330
Part 3: What If? Exploring Dierent Human Pathways 341
Chapter 8. What If? The Evolutionary Basis for Dierent
Pathways 343
Abstract 343
Introduction 345
Alternative evolutionary pathways in other species 350
Contrasts in tolerance between chimpanzees and bonobos 350
Contrasts in tolerance between wolves and dogs 356
Dierent but equal human evolutionary pathways? 366
Implications 372
Conclusions 374
Key points 375
References 377
Chapter 9. Reframing Neanderthals 387
Abstract 387
Introduction 390
Dierent types of ‘social’ 393
Archaeological evidence for contrasting patterns of intergroup
connection between neanderthals and modern humans in europe 396
Background 396
Neanderthal community relationships 397
Modern human communities 400
The structure of social networks and contrasting emotional
dispositions in social tolerance 407
Reframing neanderthals as emotionally close-knit and modern
humans as emotionally approachable 413
Diering emotional dispositions explain contrasts in the structure
of communities 413
Diering emotional dispositions explain previously enigmatic
elements of the archaeological record 415
Conclusions 418
Key points 419
References 421
Conclusions 433
What have we learnt? 433
What makes this interpretation dierent? 435
Why should this new version of our evolutionary past matter
for the future? 440
Index 443
Acknowledgements
Writing a book is often much like taking a journey and, moreover, one that
is never made entirely alone. Certainly, on this journey through the evo-
lutionary past of our human emotional connection there has been much
help along the way. Perhaps unsurprisingly, not all of this help has been
human. I’m profoundly grateful for the constant and unwavering emotional
support of Wookie (who is, as you might realise, my dog). She has always
been willing to go for a walk to think about things and has been a constant
companion, never more than a short distance away for almost every word
written. Of course, I am also indebted to the humans around me for their
support and patience, as well as more academic input from all the friends
and colleagues I have the pleasure to know and who have been happy to
listen, discuss and read drafts. Paul Mills has been ever supportive, even
through the ‘early draft which for some reason didn’t quite work’, as were
Kate and Tom at White Rose University Press. Paul O’Higgins, Calvin Dytham,
Celia Deanne Drummond, Elva Robinson, Jenni French, Sam Cobb, Phil Cox,
Laura Fitton, Paul Gilbert, Geo Bailey, Michelle Cree, David Roland, Michelle
Brenner, Gail Hitchens, Lucas Ayestaran, Taryn Bell and Callum Scott have
been particularly helpful in discussions, advice, helping with references or
reading drafts, and particular thanks are due to Kate Petherbridge for her
x HIDDEN DEPTHS
patience. Mistakes are my own. The John Templeton Foundation made this
whole project possible through ‘Hidden Depths’, grant reference: 61389,
and the Department of Archaeology, University of York, provided sabbati-
cal time. Lastly, I am much indebted to my family for putting up with the
agony of all the multiple rephrasing and rewriting that comes along with
my dyslexia, particularly my parents, my two sons Matthew and Lucas,
and my partner, Chris.
Foreword
When I rst started the research for this volume, I set out to reveal the largely
unexplored area of archaeological evidence for how some of our closest
human emotional connections emerged. The idea for the book came out
of the recognition that, all too often, evidence for what we see as the better
part of our natures is sidelined or forgotten. Narratives of our human origins
tend to either predominantly focus on discussions of violence or aggression,
or be framed within ideas of humans as purely rational beings with little
emotional motivations of any kind.
Journeys rarely go the way we envisage. Over the nine chapters, we do
uncover a remarkable record of care for the vulnerable, collaboration, and
inclusion. We learn about the collaborative group eort of early humans,
the compassionate motivations of Neanderthals, and new levels of
intercommunity tolerance. An evolutionary framework makes sense of why
our uniquely human emotional connections, sensitivities and caring moti-
vations may have paid o in our evolutionary past. Furthermore, a more
interesting and complex picture than that framed as a simple ladder of
progression towards ourselves is presented, with dierent hominin species
xii HIDDEN DEPTHS
exploring dierent evolutionary trajectories, not just of physical form but
also of emotional disposition.
However, another and perhaps even more important story also unfolded as
the volume was written. This was a story not of virtue but of vulnerability, and
one in which we become more the unwitting passengers of evolutionary pro-
cesses than its heroes. Alongside evidence for care, inclusion and tolerance
came an unexpected and rather more precious insight. As our sensitivity to
how others feel and our willingness to respond to those who need our help
emerged, so too did our own emotional vulnerabilities. Our tendencies to
act for the common good are driven by sensitivities around how others may
see us. Our willingness to care for our loved ones is underlain by often pain-
ful empathy with their suering. Our motivations to develop friendships
and companionship and a sense of belonging to extended communities are
motivated by our acute sensitivity to loneliness. All of these vulnerabilities
make us who we are and structure how we feel, motivating us to make con-
nections and to give and receive help. Moreover, it is these vulnerabilities
that, in turn, also made human groups and communities resilient in the face
of adversity. We often deride emotional vulnerability in modern societies.
However, when we look in depth at our distant past, it is clear that the more
socially sensitive and attuned to others’ feelings we became, the more our
species beneted from greater collaboration and connection.
I have been surprised by how little attention human emotional connections
and, in particular, emotional vulnerabilities have received in our evolution-
ary story. Indeed, the role that our emotional lives played in our prehistoric
past is rarely discussed. Some speculate that this may be because emotions
can appear to be rather too woolly and not scientic enough as an area of
study. I suspect, however, that it is our own discomfort with the vulnerability
that our emotions present that may have played a more signicant role. A
narrative of our past as one of invincibility, innate success and independ-
ence seems far more enticing than one that takes into account our social
emotions and, with them, interdependence and vulnerabilities. We prefer to
see ourselves as distinct from other animals because of our superior intel-
ligence, our complex language or our toolmaking abilities, even though
underneath these exterior qualities lie a complex human emotional world
and a level of sensitivity that are far more remarkable.
FOREWORD xiii
Things may be changing. Global developments in recent years have high-
lighted existential threats, such as climate change, inequality and the
COVID-19 pandemic. These threats prompt both an increasing sense of
being united by our shared futures, and a questioning of who we are as a
species. The pressing issues of climate change cast a new light on humans
as part of a wider natural world that we cannot always control, and as being
vulnerable to changes within it. The COVID-19 pandemic has prompted us
to view both our interdependence and our emotional vulnerability in a new
light. We have all felt dierently about ourselves and other people around
us. We have been moved to tears by deprivation or suering – the pain and
grief of illness, families who are hungry, people who are scared, those who
lose loved ones or are lonely. We have also grown to appreciate much more
fully the depth of our capacities to care for each other and the power of
human emotional connection. We have been inspired by the sheer numbers
of people working so hard or even risking their lives to make sure that peo-
ple they have never met were safe and well. We have missed simple human
contact and, from small acts of kindness to inspiring acts of altruism, have
grown to respect our common humanity ever more. It will be hard to forget
the power of human compassion or how vulnerable we are, as humans, to
loneliness, a lack of connection or even for many the intense grief at the loss
of loved ones. In the face of a changing climate, we are reminded of the roles
that our biology and physiology play in our lives, and how intimately we are
connected to our existence as animals, and part of nature.
Amidst all of this, our need to know why we feel the way we do, and how we
preserve the best of our experience, has never been more pressing.
Introduction
Only from the heart can you touch the sky.
Mawlana Jalal-al-Din Rumi
Aims
We readily accept that it is our emotional connections to the people
whom we love and care about that make us human. We sacrice for our
loved ones, feel joy and pain in equal measure with our friends, and even
reach out to connect to the lives and wellbeing of people we have never
met. However, we rarely think about where these feelings come from. Our
stories of human evolutionary success are so focused on intelligence, indi-
vidual resilience or strategic collaboration that you might even imagine that
our ancestors had no signicant emotional connections at all.
The aim of this volume is an ambitious one. We hope to begin to better
understand the distant evolutionary origins of our peculiarly human social
feelings and how they drive our emotional connections to those around
us. We hope to untangle why we respond so readily to others in need, why
kindness is so important, and why our rather peculiar emotional vulnerabili-
ties and sensitivities emerged. In doing so, we also hope to better under-
stand our own feelings and uncover why the evolutionary background to
our human emotional connections is important today.
We will, of course, build on existing research. Most obviously, we will build
on decades of research into understanding why human minds are unique.
How to cite this book chapter:
Spikins, P., 2022. Hidden Depths: the origins of human connection. Pp. 1–13. York: White
Rose University Press. DOI: https://doi.org/10.22599/HiddenDepths.a. License:
CC BY-NC 4.0
2 HIDDEN DEPTHS
These include approaches to the evolution of human intelligence in gen-
eral, and to specic types of ‘intelligence’ (Overmann and Coolidge 2019;
Overmann and Wynn 2019; Wynn and Coolidge 2016), including social
intelligence (Dunbar 2003; Dunbar 2018). We will consider what we can
learn from the emotional motivations of minds very dierent from our own,
such as those of our nearest living relatives, chimpanzees, and those of our
closest friends, dogs and their wolf ancestors. We will also build on a history
of research into our emotions that began as far back as Darwin himself (Dar-
win 1872).
We will also expand existing research. Within archaeology, for example,
aside from debates over evolutionary changes in emotional attitudes to
death (Pettitt 2010; Pettitt 2018; Pettitt and Anderson 2019) or to child-
care (Hrdy and Burkart 2020; Langley 2020), there has been only a limited
body of research into how the archaeological record provides insight into
the evolution of our modern social emotions or our close human emotional
connections to others. Palaeolithic archaeology, in general, has tended
to shy away from emotions, with discussions of how our minds evolved
tending to focus on subjects such as thinking skills, the basis for art, or
the origins of language (Coward 2016; Stade and Gamble 2019), or been
limited to a cultural rather than evolutionary viewpoint (Lyons and Super-
nant 2020; Tarlow 2012). Evolutionary archaeology of those most human
emotional capacities that aect our social lives is relatively novel. Further-
more, we hope to develop a wider interdisciplinary perspective on human
origins, drawing on material evidence for real people and behaviours in the
distant past.
We will bring something new. We are already aware that our human capac-
ity for social collaboration was important in our distant evolutionary past.
However, there is much more to discover about why our human emotional
connections are such an important part of our evolutionary story. We need
to delve into the specics of archaeological and fossil evidence, as well as
evolutionary understanding, to uncover what happened in our distant ori-
gins to make us capable of the emotional connections that bind us together
today. Over the 7 to 8 million years of an evolutionary past that separates us
from other apes, there have been many dierent ecological changes, selec-
tive pressures, evolutionary branches and oshoots, and many dierent
INTRODUCTION 3
societies and cultures with dierent types of social lives. It may be too much
to expect to fully understand all we might wish to about the prehistoric past
of our social emotions. However, we can at least hope to cast a far greater
insight into the peoples and societies in the distant past that helps to explain
why we feel the way that we do and, perhaps beyond this, we can hope to
gain a fuller appreciation of why our emotions and emotional vulnerabilities
are signicant for the future.
We will also attempt to move away from traditional approaches to human
evolutionary narratives (see Athreya et al. 2019; Porr and Matthews 2019).
Specically, we here move away from an idea of a ladder of progress (Athreya
et al. 2019) and from the notion of humans as exceptional (Anderson 2019).
We also seek to move beyond ideas of dierent variations of human as
superior or inferior to each other, and from a focus on intelligence as some
prime mover or dening feature of humanity (Anderson 2019). In doing so,
we hope to piece together a new narrative of our origins that plays a more
positive role in our modern worlds.
There are many avenues that have not been followed. There are voices,
including those of indigenous populations, that have yet to be heard in
our narratives of human origins (see Sterling 2015). Moreover, through the
unfortunate ease of access to archaeological material and interpretations,
we continue to rely most heavily on European material in discussions of the
most recent periods of human evolution. There are new narratives around
gender or sexuality in the past that remain to yet be told. Where we hope to
progress in particular, however, is around a greater emphasis on narratives
of physical and cognitive diversity, and in tackling the issue of dierent but
equally valid ways of being human in both the past and the present (Wright,
Spikins, and Pearson 2020).
Further, here we move away from concepts of a linear evolutionary progres-
sion to a more superior human form and, instead, move towards interpreta-
tions of evolutionary history in which there is no necessary single shared
direction of movement, and in which a model of dierent evolutionary
pathways connects more clearly with adaptations occurring in other social
animals. This is a narrative in which the signicance of our shared biology
and how it connects us to nature is more clearly emphasised.
4 HIDDEN DEPTHS
Challenges
Our emotional connections to people, and even other animals or things
around us, are a challenge to research and understand, even more so in the
distant past. They are, after all, some of the most inspiring, troubling and
problematic elements of our uniquely human experience. The eects of our
emotional connections are often intangible. Yet, we are so sensitive to how
others feel that simply being with people who care about us makes us feel
relaxed, safe and happy (Armstrong et al. 2021; Marsh 2019), and their care
makes us healthier and more resilient to stress (Gilbert 2021). The feelings of
those around us aect us so profoundly that emotions and motivations can
cascade across our social networks (Fowler and Christakis 2010). Moreover,
we are even aected emotionally by the wider economic and cultural sys-
tems in which we live (Becker, Hartwich, and Haslam 2021). As such, just as
our emotional connections can elevate us, they can also bring us down or
debilitate us. Whilst most of us discover our greatest joy and happiness in
our relationships with others, our human emotional connections also mean
that we can be disabled by grief and nd it almost impossible to live without
loved ones. We all too often nd ourselves uniquely connected to another’s
suering, crushed both emotionally and physically by cruelty or the wrong
type of social connection, or debilitated by isolation or loneliness (Bzdok
and Dunbar 2020; Gilbert 2021; Spreng et al. 2020). This emotional sensitiv-
ity seems hard to explain within a functional evolutionary framework, and
is rarely acknowledged in broader society. Yet, far from a fault, it is also an
essential part of human experience. Just living life as a human being, with
the breadth of our emotional experience and all our emotional sensitivities
and vulnerabilities, prompts us to question why we feel the way that we do,
how far back these feelings go, and why they might even have been impor-
tant for our survival.
We face a number of hurdles in building up a picture of the key develop-
ments in the complexity of human emotional connections. Firstly, we need
to draw on the often-scanty material record left behind by our many dier-
ent human relatives, a record that is not without constraints and issues. Sec-
ondly, we will need to navigate a challenging area of research lying between
commonly accepted disciplines and, lastly and perhaps most importantly,
to overcome our own assumptions and biases.
INTRODUCTION 5
In bringing the material record to bear on the question of how our social
emotions evolved, we will be disappointed if we expect some prehistoric
Pompeii, or an obvious link between how people behaved and their emo-
tional motivations. The further back we go in time, the less archaeological
evidence is preserved, and the more dicult it becomes to interpret. Like
shing in ever deeper waters, further from the surface there is less to nd
and, what’s more, we often come across unusual things that we do not
really expect. The archaeological record of the Palaeolithic, for example,
only starts with the earliest stone tools around 3.5 million years ago, and
most of our archaeological record is made up of these highly durable stone
tools, with the fortunate addition of some fossilised animal or, occasionally,
human bones. Evidence for things like art or mortuary practices, or even
the full range of the types of resources that people were hunting, gathering
and eating, are extremely rare, and are often surprising in form. Some of the
earliest mortuary practices, for example, seem to involve depositing bodies
in particular places, including caves. Quite why remains something of an
enigma (Pettitt 2010). We can only look with a certain amount of jealousy at
the often-predictable results, large sample sizes and statistical condence
seen in many other areas of science, such as modern psychological studies.
More than this, what we do nd may not be easy to interpret. The archaeo-
logical record gives us, at best, an indication of how people behaved in the
past. How they felt is something that we have to infer, and rarely is this ever
with any condence when we are dealing with single cases. What people do
is inuenced by far more than simply their emotional capacities. Rather than
expecting to nd evidence that tells us with any certainty how any single
individual might have felt, we must look instead for changing patterns of
behaviours and what that can tell us about how emotional capacities were
evolving and emerging, much as we might take the same approach to other
areas of cognitive evolution (Wynn and Coolidge 2016). As we shall see in
Chapter 2, the archaeological record for recovery from illness and injury,
demonstrating probable care from others, is a good example. We cannot
possibly be sure that someone was not cared for through some calculating
motivations on the part of someone else who might possibly have wanted
them to survive some injury for their own selsh reasons. However, when
we see a pattern of many cases of care consistently appearing across long
periods of time we can begin to reasonably infer the importance of evolved
6 HIDDEN DEPTHS
emotional tendencies to respond to others distress. We have to build an
understanding by focusing on the patterns that tell us about how emotional
capacities may have changed, and leave what any one person in the past
actually felt to speculation. Of course, we cannot help but imagine how any
individual might have felt suering some severe injury and being cared for
by those around them in the most dicult of circumstances but, when it
comes to making inferences about how emotional capacities evolved, we
will be limited to considering the patterns of broad scale change.
There are other, perhaps even more important constraints on what evi-
dence is available, and these, ironically, result from our evolved tendencies
themselves. Because we have evolved to pay the greatest attention to the
types of things which might present a danger to us – violence or conict,
for example – these elements of our distant past also attract the far greatest
attention (Soroka, Fournier, and Nir 2019). Tilley commented, for example,
that the main publications about a brain injury in the Saint-Césaire Nean-
derthal focus almost exclusively on how this injury may have been the
product of interpersonal violence, with almost no reference to the weeks
or months of survival from injury, which strongly suggests care from oth-
ers (Tilley 2015). Most of us have an image of Neanderthals as being brut-
ish, competitive and violent, even though, as we shall see in Chapter 8, the
evidence for interpersonal violence is quite scanty (with very few relatively
clear cases) compared to that for lengthy and extensive interpersonal care
(Spikins et al. 2019). All too often, it is those scant examples of violence that
attract the most attention, both academic and public. The often-overlooked
archaeological evidence for caring, supportive or sensitive behaviours will
take a certain amount of uncovering.
A natural negativity bias may have made sense in a far-distant evolutionary
world, where being particularly alert to the dangers posed by any possible
predator or dangerous situation was critical to survival. However, basing our
understanding of who we are on our intuition about what the past ought to
have been like is a risky business. Because of this bias, the behaviours of the
small numbers of others who are callous or cruel most attract our attention
and give us the impression of an innate aggressiveness to human nature
despite most of us being remarkably altruistic (Marsh 2019). A mythical vio-
lent or selsh past can be part of the assumptions we make when we create
INTRODUCTION 7
societies that bring out our worst selves and do not cater for either the bet-
ter, more caring and more tolerant part or natures, or our sensitivities.
The archaeological evidence is only half of the story. Without an under-
standing of the biological basis of how hormones inuence our emotional
motivations, and the cognitive or social psychology of behaviours set within
an evolutionary context, none of what we might nd makes sense. We will
also have to draw on insights from many dierent disciplines if we are to
understand the process through which our evolved emotional capacities
emerged. We need to understand what happens in the mind of an early
human as they perceive and respond to others’ suering, how hormones
and their evolutionary history inuence what we do, what the evidence
from fossil hominins means for the nature of changes, and the ways in
which ecological circumstances drive species along dierent evolutionary
branches. This type of interdisciplinary research is always challenging. As
academics, we tend to be encouraged to stay within our disciplinary bound-
aries and become ever more specialised in a single area. The patterns and
processes occurring in the past, from which our evolved emotional capaci-
ties emerged, did not happen in one neatly dened realm, however. From
the biology of hormonal responses, to cognition, to ecological changes,
social relationships and even cultures, we will have to have some grasp of all
of these things to make sense of the evidence.
Perhaps the most signicant challenge, however, comes from within – that
of overcoming our own assumptions of and preferences for what the tra-
jectory of our evolutionary past should look like. It is all too easy to write
a pleasing narrative around the evolutionary past we want to believe in,
whilst the actual history behind our emotional capacities may be far more
useful to us.
Most obviously, we much prefer a success story. We almost always hear of
human origins through a narrative of gradual progression towards a nal
form, ourselves, who we see as a kind of pinnacle of evolutionary success
(Scott 2010). Indeed, the idea that evolution made us perfect, and that as
a species we triumphed over adversity to become uniquely successful, is
so hard baked into our culture that it can be hard to see past it. Surely, we
reason, we must be better than any human species that came before us.
8 HIDDEN DEPTHS
Not only in physical form, intelligence and technological capacity but also
in emotional capacities. The ultimate success story. More advanced than any
other on the planet.
Rather than a simple progression, there is abundant evidence for a much
more complex story that speaks to us less of ‘success’ and more of a
sequence of adaptations and changes, some more random than others.
Recent years have demonstrated that human evolution is far more com-
plex than we often assume, for example. We now know that there are many
more species of human, existing in a complex relationship with each other,
rather than any single evolutionary lineage (Galway‐Witham, Cole, and
Stringer 2019). More than this, evolutionary processes themselves are much
more chaotic and undirected than we often assume. Dierent species sim-
ply adapted by responding to constraints and opportunities in ways that
brought both advantages and disadvantages, but not intrinsically ‘better’
or perfect forms. Rather than any step being better, there were always com-
promises to be made. Human brain expansion facilitated great cognitive
advancements, for example, but at the cost of high energy expenditures and
risks in childbirth. Bipedalism may have freed up hands and brought certain
energetic advantages, but imposed stresses on the spine. The same possi-
bilities, constraints, advantages and disadvantages are true of how social
emotions emerge. Shame or guilt may motivate more moral behaviour, for
example, but can also come at a price. Shame, in particular, can have lasting
negative eects on wellbeing (Longe et al. 2010). Moreover, certain changes
or adaptations are often part and parcel of other developments, ‘hangers on’
in genetic terms, or simply made little dierence. A simple story of evolu-
tion as a ‘better’ form winning out over others, or anything being ‘perfectly
evolved’, is more myth than reality. Only by understanding the complexity
of branches and compromises can we move away from our perhaps rather
colonially inspired narratives of superiority and inferiority, and of anatomi-
cally modern humans (henceforth ‘modern humans’), our own species, as
naturally somehow exceptional. Even using the term ‘modern human’ for
our own species is problematic, as it seems to imply a certain superiority. We
may now be the only such surviving species but others to which this term
could equally apply were our contemporaries for tens of thousands of years.
There is, however, no better option that everyone understands.
The often chaotic and non-directional nature of evolutionary processes
is perhaps even more signicant to bear in mind when considering our
INTRODUCTION 9
emotions than any other human capacity. In the eld of emotions, chance
factors and the vagaries of circumstances play an important role in how
capacities evolve and, moreover, compromises are rife. As we shall see, our
evolved emotional capacities make us social, in the sense of being highly
sensitive to each other’s feelings, and highly responsive to culture, but also
vulnerable, desperate for recognition, debilitated by grief, and made ill with
loneliness. Our acute social sensitivity can be an advantage to collaboration,
but also a vulnerability where we grasp at attention or follow a herd going in
perhaps the wrong direction.
To nd a more nuanced and more interesting explanation for the role our
emotional connections played in making us who we are, we may need to
let go of the comfort and satisfaction that come with believing we are some
kind of pinnacle of a process of increasing perfection. This may not be a
neat story. Nonetheless, that our shared human capacities for remarkable
generosity, sharing, tolerance and altruism came about through imperfect
responses, compromises and changes in direction, may make them even
more remarkable.
Structure
We address dierent types of human emotional connection across the three
parts of the volume. In the rst two parts, we focus particularly on two suites
of emotional capacities: in Part 1, those particularly focused on our emotional
connections within groups, particularly our generosity and compassion for
close kin and group members and increasing importance of trust and social
reputation; and, in Part 2, those emotional connections driven through tol-
erance, sensitivity and connection to people outside of our local or family cir-
cle. These two distinct areas naturally lead to a focus on two key transitional
periods in human origins. The rst key transition, explored in Part 1, around
the time of the origins of the genus after 2 million years ago, coincides with
new types of collaboration based on sharing and caring behaviours within
groups. This may be the time period when typically human generosity and
compassion emerged, with implications for the signicance of trust, and for
broader areas of social relationships and cognition. More in-depth emotional
connections emerging at this time will have brought with them increased
pain at others’ suering, and concern for group wellbeing. The second key
transition, explored in Part 2, is that of the emergence of our own species
after 300,000 years ago, coinciding with evidence for regional connections
10 HIDDEN DEPTHS
between groups, based on new types of tolerance and the maintenance of
friendships across large regions. This may be the time period when typically
human needs for connection and belonging emerged, alongside capacities to
form large-scale social networks, as well as sensitivities and vulnerabilities
to emotional stresses and loneliness. In each of these two parts, we start
with the evolutionary basis for key traits, move to archaeological evidence,
and then consider the implication for our current interpretations and wider
signicance. In Part 3, we explore diering branches of emotional disposi-
tions, the emotional lives of our close cousins, the Neanderthals, and how
the dierences between us may be explained by alternative, though dif-
ferent but equal, evolved emotional trajectories. Lastly, we consider why a
reappraisal of the signicance of our most human emotional capacities may
be important for our understanding of human origins and beyond.
A new narrative may reveal not only the signicance of previously disre-
garded elements of past human lives, but also new perspectives on ourselves.
INTRODUCTION 11
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Part 1
Compassion, Generosity
and Trust
In this part of the volume, Part 1, we consider how and why our remarkably
strong emotional bonds and tendencies to altruism within close-knit fami-
lies and groups emerged. We begin in Chapter 1 with the evolutionary basis
for our human capacities for empathy, compassion and generosity, before
continuing in Chapter 2 to consider the archaeological evidence for caring
behaviours for vulnerable group members. In Chapter 3, we consider the
signicance of increasing pressures to be trustworthy and to develop a posi-
tive social reputation, as well as the role of reputation in fostering human
cognitive diversity. We particularly focus our attention on key changes tak-
ing place early in our evolutionary history with the emergence of the genus
Homo after 2 million years ago.
Why do we have such strong attachments to our loved ones? What makes us
so willing to help out the vulnerable? And how important has our capacity
for compassion been to our evolutionary history?
CHAPTER 1
The Evolutionary Basis for Human
Empathy, Compassion and Generosity
Abstract
How did we come to care so much for our loved ones, and to respond
so readily to those in need?
If we look around at the types of empathy and emotional connec-
tions in other animals, we can gain some insight into the basic build-
ing blocks of our empathy, compassion and generosity. Studies of
helping behaviour in other species can provide us with some impor-
tant insights, for example. If we go back to basic roots as mammals
we can see that this evolutionary history has formed the basis for our
capacities for empathy, stemming from a need to respond to vulner-
able young. However, human empathy, compassion and generosity is
certainly more complex. This is where studies of our nearest living rel-
atives, chimpanzees, provide insights into more complex capacities
to share and to respond to others distress, as well as a certain social
astuteness that is likely to have characterised the emotional capaci-
ties of our common ancestor living about 7 to 8 million years ago.
(Abstract continued on next page)
How to cite this book chapter:
Spikins, P., 2022. Hidden Depths: the origins of human connection. Pp. 17–70. York:
White Rose University Press. DOI: https://doi.org/10.22599/HiddenDepths.b.
License: CC BY-NC 4.0
18 HIDDEN DEPTHS
What happened after our split with other primates? How our emo-
tional capacities evolved after our lineage split with other apes is
a challenging question. Here animal comparisons reveal a certain
paradox. Some far more distantly related animals demonstrate a
more human-like altruism and compassion than those that are most
closely related to us, such as demonstrating a certain willingness to
collaboratively care for ospring, or to care for vulnerable injured
adults, for example. Understanding what prompted these kinds of
changes in human ancestors who came after our split with the ances-
tors of chimpanzees demands considering how dierent species nd
the best ways of adapting to the ecological and social environments,
and how this aects their emotional reactions to each other.
Explaining the depth and breadth of our emotional connections to
others remains a challenge. Building up our understanding of how
and why human emotional motivations towards generosity and
compassion emerged over the last few million years also depends on
archaeological evidence of when helping and compassionate behav-
iours emerged, and why they became important, which is the focus
of Chapter 2.
(Abstract continued from previous page)
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 19
Introduction
Sometimes animals surprise us by doing something that seems uncannily
human-like.
Marmosets (South American monkeys of the family Callitrichidae) are tiny,
weighing only around 300–400g, and though they are primates they look
entirely unlike humans, perhaps even a little more like squirrels. However,
like humans they form pair bonds, and collaborate in childcare (Figure 1.1).
Moreover, experimental research has shown that, given a chance to help
others to reach a food treat, even if they know they do not get one them-
selves, marmosets will commonly put a lever to get food for others (Burkart
et al. 2007). They will even resist the temptation to eat food whilst they wait
for others to arrive to share.
Figure 1.1: Family of Common Marmosets. Common marmosets – both
male and female caring for the two small infants. Francesco Veronesi,
CC BY-SA 2.0 via Wikimedia Commons: https://commons.wikimedia.org
/wiki/File:Family_of_Common_Marmoset_-_REGUA_-_Brazil_MG_9480
_(12930855765).jpg.
20 HIDDEN DEPTHS
Such a strength of emotional connection, seen through apparent acts of
compassion or generosity, seems to resonate with our own feelings towards
those we care about. However, seeing this kind of altruism outside of our
own species can raise more questions than answers. Willing generosity to
others in their group, and a response to their distress or needs, occurs in
many species unrelated to humans, whilst those nearest to us are not neces-
sarily the most altruistic. Whilst our nearest relatives, chimpanzees (mem-
bers of the genus Pan, including common chimpanzees, Pan troglodytes,
and bonobos, Pan paniscus), are without doubt the most socially intelligent
of other animal species, they are not the most like humans in terms of gen-
erosity and compassion. Tiny marmosets are far more likely to be generous
to others. Moreover, entirely unrelated mammals such as lions or wolves
seem most similar to ourselves in their tendencies to take risks on others’
behalves, care for each other or share food.
What can we learn from other animals about the biology of human generos-
ity and compassion? What types of selection pressures may have led to the
emergence of our own capacities to be compassionate or generous?
To begin to address this question, we rst look at what happens in our brains
when we feel empathy, compassion and a willingness to help others. Simply pos-
sessing a capacity for empathy and altruistic motivation does not, of course,
provide any guarantee that we will apply those in practice. There are many
reasons why any particular person, in any particular time or place, may feel a
sense of empathy or compassion or may or may not reach out to help others.
Our experience through childhood can provide important insight into how our
altruistic motivations develop, with potential signicance for understanding
of our own evolutionary history. The constructive helping that we see in the
collaborative childcare demonstrated by marmosets is relatively complex
compared to simpler emotional reactions to others’ distress.
Understanding the situations in which emotional motivations to help others
may have been advantageous helps to situate human evolutionary change
within a wider evolutionary context. Comparisons with other primates and
with more distantly related but highly collaborative species such as social
carnivores provide further insights into the selective pressures acting on
human emotional motivations towards others.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 21
How do we respond to another’s distress?
The neurobiology of compassion
Empathy
We rarely pause to think about what actually happens in our minds when we
reach out to console someone or respond to another’s distress. In fact, if we
try to search inwards to understand exactly what sort of processes or feel-
ings are involved, it becomes almost impossible to gain any kind of clarity.
A whole series of feelings, thoughts, assumptions and levels of emotional
awareness are involved in enabling us simply to reach out and touch some-
one who seems distressed, but they happen so quickly and intuitively that
we are rarely aware of them.
At the root of our emotional connection to others is empathy. We feel empa-
thy for example when we sense a friend is upset or in trouble and might,
for example, say that we feel for them. Empathy tends to be associated
with our response to distressing feelings (as when, for example, we say we
‘feel another’s pain’ or when we sense someone is afraid). However, we can
also feel empathy for pleasurable and positive feelings, as is the case with
empathetic joy. In a fundamental way, our capacity to empathise with others’
feelings links people emotionally.
Whilst we often think of human empathy as elevating us above other ani-
mals, our empathy or ability to understand and share another’s feelings is
shared with many other social animals. The origins of our capacity to con-
nect to others’ feelings may even be ancient. Many people speculate that
some level of sensing how others feel may even date as far back as 300 million
years ago, with the rst examples of animals who nurtured living young.
Fossils of lizard-like creatures found in Canada, for example, appear to show
an adult protectively curled around its young (Maddin, Mann, and Hebert
2019), behaviours that would eventually be seen in birds and mammals. It
was amongst the ancestors of modern mammals, hamster-like cynodonts
living around 250 million years ago, however, that a more pronounced
infant dependence and maternal willingness to respond to the vulnerabil-
ity and distress of their infant formed the basis of mammalian empathy
(Brethel-Haurwitz et al. 2017; Marsh 2019). The brain structures and hormo-
nal responses that allow us to sense others’ feelings are common across all
mammals (Feldman 2017).
22 HIDDEN DEPTHS
The evolutionary reasons why mammals of all species feel empathy, particu-
larly for their young, are well understood. Mammals are warm-blooded and
typically give birth to live young, who are born vulnerable and immature
and depending on their mothers for care (Marsh 2019; Snowdon 2011). This
dependency means that, from rats to dolphins to horses, mammals need
to be highly sensitive to the feelings and needs of their infants to pass on
their own genes. Moreover, infants themselves develop a strong sense of
attachment to caregivers, which inuences their emotional relationships
later in life (discussed in Part 3). Quite simply, those mothers who were best
at detecting distress in their ospring were more likely to respond to their
needs, perhaps a little quicker to provide them with food or warmth, for
example, and were therefore more successful as parents, better able to raise
healthy young. Infants who were better at eliciting support were themselves
more likely to survive.
Although there are many complex social and cultural processes that inu-
ence how we react to other people around us, there are still signs of the
biological basis of our empathetic and caring responses. As infants we intui-
tively begin to willingly act altruistically from as young as one and a half
to two years of age, regardless of culture (Tomasello 2014; Warneken and
Tomasello 2007). We are highly tuned to others’ emotions, and our capaci-
ties to identify fearful faces at only seven months old are related to later
altruistic tendencies from 14 months onwards (Grossmann, Missana, and
Krol 2018). As adults, common human acts of altruism towards strangers
such as giving to charity or donating blood have an intuitive emotional
basis rather than being calculated responses (Marsh 2019). Moreover, those
of us with a greater density of oxytocin receptors, and so more responsive
to the action of this important bonding hormone, are more likely to carry
out extraordinary acts of altruism, such as donating a kidney to a stranger
(Brethel-Haurwitz et al. 2017).
What seems a relatively straightforward maternal response to distress
in young has formed the neurological and hormonal basis from which
our empathy in a whole range of other situations has evolved (Decety
et al. 2012). Of course, some mammals only respond empathetically to their
own infants and not to other infants or other individuals. However, social
mammals who depend on collaboration to survive, such as social carni-
vores, show a similar empathetic response to closely related adults in their
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 23
group who are injured or who need food. Collaborative mammals respond
not only to their own young but to the young of other parents, collabo-
rating in infant care (Decety et al. 2016; De Waal and Preston 2017; Frank
and Linsenmair 2017; Kokko, Johnstone, and Wright 2002). Much of the
complex collaboration in highly social mammals depends on being able to
sense how others feel and respond by helping them appropriately (Decety
et al. 2016).
The neurobiology of human empathy links our responses to this shared
mammalian heritage. The same brain areas that are responsible for attend-
ing to vulnerable infants and are common to mammals as a whole have
been co-opted in human empathy (Decety 2015; Decety et al. 2012; Pank-
sepp and Panksepp 2013). There are many things that mark humans as
distinctive. For humans, however, our empathetic responses can be trig-
gered in a far wider range of situations than in any other animal, from our
response to seeing photographs of our babies to our response to accounts
of people in need. Nonetheless, our mind responds with the same brain
regions (conserved neural circuits connecting brainstem, basal ganglia,
insula and orbitofrontal cortex) and with a similar system of hormones as
that in other animals (Decety 2015; Decety et al. 2012; Tousignant, Eugène,
and Jackson 2017). Neuropeptides such as oxytocin and dopamine play
particularly important roles (Madden and Clutton-Brock 2011). Oxytocin
regulates lactation and maternal infant bonding in mammals as a whole,
as well as some social behaviours in adults, such as teaching in meerkats
and food sharing with non-kin in chimpanzees (Madden and Clutton-Brock
2011; Wittig et al. 2014). However, in humans this same hormone also
plays a role in generosity, trust and altruism between non-related humans
(Barraza and Zak 2009; Baumgartner et al. 2008; Kosfeld et al. 2005; Zak,
Stanton, and Ahmadi 2007). Higher levels of oxytocin, in turn, have a posi-
tive eect on health (Gouin et al. 2010). Whilst oxytocin is a good example,
other hormones are, of course, also important. Vasopressin plays an impor-
tant role in caring behaviours, and dopamine drives reward-seeking behav-
iour that can be important in fostering repeated helping behaviours (Marsh
2019), as discussed in more detail in Chapter 6.
We would, of course, be wrong to see human empathy as simply about
inherited neurobiology and hormonal responses. We know that our emo-
tional responses to people around us, and our decisions to respond to
24 HIDDEN DEPTHS
others’ distress or to act in generous ways, are far more complex than our
biology. We are inuenced by our moral judgements about others (Decety
et al. 2012), our strength of trust or emotional commitment to them (explored
in Chapter 3), and even wider social and cultural norms and assumptions
(Becker, Hartwich, and Haslam 2021), as well as our conscious choices
and decision-making. Nonetheless, our biology, and our involved capacities
deriving from our distant evolutionary past, still play an important and often
overlooked role in how we feel about other people and, in turn, how we
behave. Moreover, the relationship between biology and culture is a com-
plex one. As discussed in Part 2, our sensitivity to social and cultural context
itself has a biological element, with this sensitivity an important way in which
our minds can be primed for survival in caring or competitive contexts.
From empathy to constructive help
Empathy alone does not necessarily motivate any specic behaviour. Rather,
it is only through a sequence of often complex feelings and thoughts that
we can empathetically respond to others’ needs. Through empathy we
identify how others feel and, in some cases, our motivations to help them
translate into compassion (Gilbert 2015; Goetz, Keltner, and Simon-Thomas
2010), whilst deciding what to do may involve many higher-level processes
(Decety et al. 2012; Marsh 2019).
A lot goes on in our minds when we sense someone else’s fear, distress or
needs and respond to them. From feeling an empathetic response to con-
structively helping someone involves several levels of neurological pro-
cessing (see Figure 1.2 and, for a fuller explanation, Decety et al. 2016). We
identify someone’s emotional distress according to factors such as our own
Figure 1.2: Illustration of emotional and cognitive responses leading from
empathy to helping behaviour. Penny Spikins, CC BY-NC 4.0.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 25
experience, our interpretation of their gestures or expressions, and our
social context. This can then lead to a change in our own emotional state,
often under the inuence of a hormonal response such as that directed by
oxytocin release, towards a motivation to help. This can then lead to the
action of helping, depending on our cognitive appraisal of the circum-
stance and whether helping is constructive. Helping behaviours can lead
to a reduction in our emotional stress (we feel better), a hormonal response
(or ‘warm glow’), or a sense of reward or achievement (under the control of
dopamine), which leads to a reinforcement of helping.
Whilst we all share common inherited capacities to empathise and respond
to others’ needs, these several levels of response are also dierently aected
by our immediate context, past experience and individual dierences. These
include inherited dierences (such as in oxytocin receptor densities; Marsh
2019), our immediate intimate social environment and the extent to which
this has fostered a sense of security and trust (discussed further in Part 2),
and the attitudes of our surrounding culture and our individual beliefs. While
most of us respond intuitively as infants when people need help, our dier-
ent cultures guide how we behave as adults and whether or not we squash
our intuitive empathetic responses (Rajhans et al. 2016). Most of us help
out someone when we ‘warm to them’, when we feel we can, and when we
feel that their distress is genuine and undeserved, but none of us responds
to the distress of vulnerability all of the time.
There are times in everyone’s lives when we fail to be compassionate to
others around us. This is not just because stress, anxiety or depression can
hamper our abilities to connect emotionally to others. Though we cannot
remember it, we have all experienced a time as infants before we devel-
oped our capacity to respond compassionately to others. Whilst our journey
from infancy to adulthood cannot be taken as a model for our evolutionary
journey as humans from a distant mammalian past, it does give us some
insight into potential stages in our abilities to connect to others’ feelings
and respond to them.
Growing into our empathy: progressively complex responses
through childhood development
If we could only remember our infancy better than we do, how we felt when
we were babies and infants might give us a fascinating insight into dierent
26 HIDDEN DEPTHS
stages in human emotional connections to others and capacities to reach
out and help.
As babies, we all start life at the simplest level of empathy – capable simply
of emotional sharing, but nothing more complex. Emotional sharing or emo-
tional contagion is the simplest element of empathy. Emotional sharing is
driven by a sense of another’s emotions through an association with a repre-
sentation built on our own experience – the perception–action mechanism
or PAM (De Waal and Preston 2017). As human babies, we show emotional
contagion when we respond to hearing the cries of other babies by crying
ourselves and illustrate a basic element of empathetic capacity in doing so.
However, whilst this capacity illustrates a certain sensitivity to the feelings
of others, simply sharing others’ feelings is neither true empathy nor of con-
structive help. For example, when a peer is distressed monkeys display emo-
tional contagion by screaming in turn in excitement (de Waal 2008). Whilst
this emotional sharing is the basis of our emotional connection to those
around us, it is not necessarily actively helping the individual in distress. In
fact, in the case of the screaming monkeys, behaviours prompted simply
by emotional contagion may actually make the distress worse – screaming
alongside an individual in distress is not necessarily helpful and monkeys
may even react by jumping on the distressed individual. A room of crying
babies demonstrates a certain sensitivity, but, as many of us may have expe-
rienced, generally makes everyone, from the adults to the babies them-
selves, feel worse.
Thankfully, we quickly progress during infancy to more sophisticated levels
of emotional connection. Diering levels of empathetic response are often
thought of in terms of increasingly complex ‘shells’ – from the simplest emo-
tional contagion to empathic concern and consolation and an integration
with higher-level cognitive functions leading to more complex perspective-
taking and targeted helping (Figure 1.3; for a discussion of diering levels of
empathy, see De Waal and Preston 2017).
Empathetic concern and consolation are somewhat more cognitively com-
plex and involve an ability to withstand both our own emotional reaction
(our emotional or aective empathy) and that of others without being over-
whelmed and to respond appropriately. By the time we are one year old, we
are able to respond with empathetic concern and show some attempts at
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 27
consolation. Apparently cute attempts by one-year-olds to provide some
emotional support through touch or sympathy illustrate quite a complex
advance in their emotional skills.
Consolation may seem a relatively simple form of compassionate behaviour
towards others; however, even this ability tends to be restricted to highly
social mammals. Elephants, for example, respond to those who are in dis-
tress with physical contact and vocalisation (Plotnik and de Waal 2014).
Wolves (Canis lupus) appear to ‘feel for’ the losers in a conict, even if they
were ‘bystanders’ and not involved, and console them through behaviours
such as body contact, play or social licking (Palagi and Cordoni 2009).
Patterns of consolation are widely recorded in apes, who ‘hug’ the losers of
conicts (Romero, Castellanos, and de Waal 2010). Bonobos (pygmy chim-
panzees), in particular, seem notably attuned to others’ distress and willing
to respond with gestures of comfort (Clay and de Waal 2013); see Chapter 7.
These types of sensitivity to others’ feelings and capacity to ‘reach out’,
physically calm distress and diuse social tensions, with consolation in pri-
mates being shown to reduce anxiety (as seen in scratching) and heart rate
(Aureli, Preston, and de Waal 1999; De Waal and Preston 2017; Fraser, Stahl,
and Aureli 2008). Highly social animals that depend on each other’s help
to survive tend to show greatest tendencies to respond to others in the
group, and to be the most aliative and aectionate to each other (Snow-
don 2011). Pair-bonded marmosets are often found sitting with their tails
twined together, and frequently turn to each other for aection and a sense
of security. Though we tend to think of social carnivores like wolves, lions
(Panthera leo) or hyenas (members of the family Hyaenidae) as erce (and
they certainly may be so towards us), they are highly aliative and aection-
ate amongst themselves even as adults. That they feel a pleasurable sense of
contentment at this aection towards each other, and also crave closeness
Figure 1.3: Levels (or shells) of empathetic abilities we experience from our
earliest infancy to later childhood, and share with some other social ani-
mals. Penny Spikins, CC BY-NC 4.0.
28 HIDDEN DEPTHS
and strong aection of bonds, keeps them together as a cohesive group.
This same reassurance of emotionally sensitive touch is equally important
to us (Suvilehto et al. 2019). Though we like to feel that, as humans, we are
exceptional, much of the biology of our consolation behaviours connects us
to other social animals.
A reassuring touch is helpful but what about actual practical help? More
complex cognitive appraisal (more complex thinking processes) is needed
to move from empathy to more constructive compassionate action that
goes beyond reassurance. This involves empathetic targeted helping. Empa-
thetic targeted helping may be something we do every day in the smallest of
ways when we open a door for someone, help them with something heavy,
or the slightest of everyday actions. However, quite complex emotional and
cognitive abilities underlie these behaviours. Typically, from around one
to two years old we will start to be willing and able to help constructively
(Vaish, Carpenter, and Tomasello 2009). In order to actively assist someone,
we often need to place ourselves mentally ‘in their shoes’ (cognitive empathy
or perspective-taking) and formulate an appraisal of what might help. We
might, for example, notice that something is out of someone’s reach and
get it for them.
Targeted helping is somewhat rarer than consolation in the animal king-
dom but is not unique to humans. Highly social animals will often respond
to explicit pleas for help, such as responding to begging for food. Active
response to distress has been recorded in several highly social mammals
such as dolphins, wolves, elephants (members of the family Elephanti-
dae) and rats (members of the genus Rattus) (Pérez-Manrique and Gomila
2017). Provisioning of ill or injured adults has also been recorded in a range
of animals including mongoose (Helogale parvula) (Rasa 1983) and otters
(Pteronura brasiliensis) (Davenport 2010). Social carnivores have even been
known to provision ill or injured individuals with food for some consider-
able time, with a case of a wounded lioness being provisioned by others for
nine months (Hart 2011; Schaller 2009). Behaviours that help are often more
instinctive than explicitly thought through – tending wounds, for exam-
ple, is a common extension of grooming behaviour that improves heal-
ing (Hart 2011). Provisioning of food to ill and injured peers or attending
to their wounds may be an extension of the type of care typically given to
vulnerable infants but nonetheless may signicantly improve their chance
of survival.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 29
Sometimes a response to distress appears to involve a more clearly explicit
appraisal of the situation and of what might help. Chimpanzees, for example,
will sometimes spontaneously help someone who needs something out of
reach (Melis and Tomasello 2013; Warneken et al. 2007). There are reports
of chimpanzees occasionally providing food for others without simply acqui-
escing to a demand (Boesch 1992; Pérez-Manrique and Gomila 2017). In one
case, an adolescent male helped a mother to carry her infant for a period of
two days when illness forced her to drop behind the group (Pruetz 2011).
Dolphins (members of the family Delphinidae) will support another injured
dolphin at the surface so that it can breathe, for example, and elephants
will lift another elephant who has fallen or cannot stand (Douglas-Hamil-
ton et al. 2006; Pérez-Manrique and Gomila 2017). They may understand
the distressed animal’s need and desire to be supported or lifted, and how
they themselves can make that happen, although, of course, it is always dif-
cult to be sure whether surrounding animals are acting in intuitive ways
as if their peer were a vulnerable infant or if they truly understand the situ-
ation. Evidence for a level of appraisal of the situation nonetheless exists
in some instances. Rats who have been taught how to use a lever to get a
food reward will choose to free a familiar rat in distress over the opportu-
nity to press for chocolate (Bartal, Decety, and Mason 2011). In eect, the
rats are making choices about dierent outcomes, taking into account their
emotional responses to the distress of a cage-mate as well as their cognitive
appraisal of how to help. When we respond to someone who needs help, it
might feel like a simple act, but even simply helping involves a sophisticated
emotional attunement and motivation to help, as well as cognitive appraisal
of what would be helpful.
Few of us have any idea when we rst reached out to help someone else
who was in distress or needed help, or when we helped others without any
cues. We tend to pay particular attention when infants rst start to speak,
or when they show some kind of complex spatial intelligence. However, the
point at which we rst understand that someone else needs our help and
we reach out to help them is an often-overlooked but possibly far more sig-
nicant turning point in our development. That we share this turning point
with other animals makes it no less remarkable.
Most of the occasions when we connect emotionally to people around us,
comfort someone close to us, or share our joys or sadnesses, leave no trace.
For some helping behaviours there is at least some possibility, nonetheless,
30 HIDDEN DEPTHS
of surviving material evidence from the past, such as the remains of people
who might never have recovered from their illnesses or injuries without
some help from others, explored in Chapter 2. We also nd material evidence
for how people treat those who have died, or mortuary practices. A more
complex relationship, however, exists between empathy and responses
to death.
How does empathy for the living relate to how we treat people after death?
The emotional meaning of responses to death in other animals is something
that is often hotly debated. When does empathy end? Many mammals,
such as dolphins, sea otters and elephants, as well as other apes, continue
to express nurturing behaviour even to dead individuals (Gonçalves and
Biro 2018; Reggente et al. 2016). This type of behaviour is most common
with deceased infants. There are well-known examples of chimpanzees at
Boussou, Guinea, carrying the mummied remains of their dead infants
for several weeks (Biro et al. 2010; Fashing and Nguyen 2011; Fashing et al.
2011). It is also recorded with dead adults. Apes can show distress at the
death of an adult group member, particularly in the cases of traumatic
death, spending time with or handling the body (Anderson, Gillies, and Lock
2010), behaviour also seen in species such as elephants (Bearzi et al. 2018;
Douglas-Hamilton et al. 2006) and free-ranging dingoes (Appleby, Smith,
and Jones 2013). Of course, in strict evolutionary terms, given all the costs
involved in raising an infant and that there may be conditions or illnesses
from which infants will recover with continued care but from which they
may lose consciousness or appear to be inanimate, it may only make sense
not to give up too soon.
Whilst continuing to show some signs of nurturance after death is not com-
passionate helping as such, it may be inuenced at least in part by gener-
alised empathetic responses to an individual who appears to be vulnerable
and in need of support. Attitudes to death in other animals are nonethe-
less extraordinarily dicult to interpret. We cannot, after all, ‘get inside their
heads’ to understand what they are thinking and feeling. The reactions of
animals to dead members of the group illustrate some of the diculties
we have in interpreting what apparently similar behaviours expressed by
animals to ourselves actually mean, or indeed what any mortuary practices
in the very distant evolutionary past might have meant. It seems certainly
reasonable to conclude that many animals, not only other apes and other
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 31
primates but also elephants or dolphins, show a level of emotional connec-
tion to others, and are distressed by the death, and that this may reect a
sense of loss (Reggente et al. 2016). This is not the only explanation, how-
ever. Their responses may also be related to the psychological incongruity
of something that is usually alive and yet is inanimate (unmoving) (Gon-
çalves and Biro 2018). We remain uncertain to what extent non-human ani-
mals understand what ‘death’ means. It is clear that the death of a close peer
feels disturbing, but exactly what goes on in the minds of animals who are
clearly upset is a question that remains largely unresolved. Likewise, though
closely related human species to our own, such as Neanderthals, must have
experienced a very similar sense of loss to our own, when far more distantly
related humans deposit a body of their dead kin somewhere particular they
clearly feel some sense of loss, but what that death means to is something
of a complex mystery.
Disentangling evolutionary mechanisms
Why did we evolve to care so much? Disentangling the evolutionary basis
for complex caring behaviours can be challenging.
We can be reasonably condent about some of the key processes that drive
general tendencies towards altruism in humans as well as other animals
(described below), even though the relative importance of dierent pro-
cesses may not be entirely clear. However, when it comes to specic behav-
iours, such as reactions to the death of peers or care and provisioning of ill
or injured adult group members, the selection pressures mechanisms that
lead to this behaviour can be dicult to understand or disentangle. Some
behaviours are strongly inuenced by learning and culture. For example,
chimpanzees from a particular region of Guinea have been recorded car-
rying around the corpses of their dead infants for some time after death,
although this is only very rarely observed in other regions, suggesting that
the behaviour is not just about genetic inheritance (Biro et al. 2010; Lonsdorf
et al. 2020). Their distress seems to be translated into this particular behav-
iour because they have observed it and learnt this as the usual response,
and other behaviours in chimpanzees, such as particular types of grooming
or uses of tools, are similarly subject to cultural dierences (Vaidyanathan
2011; Whiten et al. 1999). In other cases, it is dicult to know whether any
particular behaviour has been subject to specic selection pressures for
32 HIDDEN DEPTHS
precisely that behaviour, or is part of far more general tendencies. Contin-
ued nurturance of infants, even when they appear to be inanimate, may be
a behaviour that is specically selected for. Mothers who behave in this way
over long timescales have the potential to be more reproductively success-
ful because of the cases of apparently unresponsive infants who eventually
recovered. However, this behaviour might equally simply be a side eect
of far more general responses to vulnerable infants, rather than specically
selected for in its own right. In the same way, care and provisioning of ill
and injured group members may just be a side eect of general tendencies
to help out vulnerable individuals, rather than being specically selected
for, even if this behaviour does have a notable impact on future survival,
perhaps of family members, and we can construct a plausible explanation
for its emergence (as discussed in Chapter 2). Our plausible evolutionary
explanations do not necessarily prove that the selection pressures that we
might imagine were the critical ones inuencing any particular behaviour.
Plausible arguments, or ‘just-so’ stories, without any evidence, are not neces-
sarily correct just because they appear to make sense.
Far from being, as we often imagine, a process that leads to increasingly per-
fect forms, evolutionary selection pressures often create apparently strange
traits or behaviours that are dicult to explain. Particularly famous amongst
these is the case of the peacock’s tail, created through male competition to
attract females who themselves judge the quality of a potential mate on
the basis of their resplendent but highly impractical tailfeathers. Male pea-
cocks (members of the family Phasianidae), despite being rather beautiful,
are very far from being well adapted to practical survival. Before he under-
stood processes of sexual selection, Darwin found explaining the exotic and
impractical plumage of the male peacock a notable challenge (Richards
2017). Whilst we understand a great deal, there are still many processes that
remain an area of debate.
Why be kind? The evolutionary advantages of compassionate
helping behaviours
The reasons why any animals, and we as humans, might develop extensive
and in-depth emotional responses to help others have been the subject of
much research in biology.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 33
It is not dicult to explain why selective pressures encourage a maternal
response to infants’ needs. However, we might wonder why the cost of eort
on behalf of an adult could ever be an advantage, how empathy beyond
that for vulnerable young might have evolved, and why this tendency is
more pronounced in some species (particularly our own) than in others.
The proximate (or immediate) cause of helping behaviours lies, as we have
seen, in the particular neurological, hormonal and cognitive capacities that
govern responses to others’ distress. However, the ultimate (or longer-term
evolutionary) cause of such behaviours lies in how selective pressures aect
the ways in which the emotional and cognitive capacities of dierent spe-
cies evolve. In certain ecological and social contexts, responding to others’
needs may be benecial in an evolutionary sense, and thus these contexts
exert selective pressures on existing capacities.
In dierent contexts, emotional motivations to help others can benet
those with such capacities in several dierent ways (see Table 1.1).
In many cases, helping directly improves reproductive success such as
when the recipient is a close relative and, in this case, helping (or kin-based
altruism) makes evolutionary sense as a way of safeguarding one’s genes.
This is the case not only in care of the young but for many social mammals
who parent collaboratively or share proceeds from collaborative hunting.
The benets of helping each other in the context of a dependence on work-
ing together and sharing food to survive places evolutionary pressures on
emotional motivations and cognitive abilities to respond altruistically to
other group members. Some social carnivores, such as grey wolves, not only
parent and hunt collaboratively but provide for, and even defend, sick or ill
group members as they would ospring (i.e. by regurgitating food; Barber-
Meyer et al. 2016), as well as taking risks to defend other adult pack mem-
bers (Cassidy and McIntyre 2016; Jouventin, Christen, and Dobson 2016).
These kinds of behaviours (and so the proximate cognitive-emotional basis
underlying them) tend to ‘pay o’ in the long term.
Collaborative or mutualistic altruism can also benet individuals who are not
closely related. In such cases, the ‘costs’ of helping are often rewarded in dif-
ferent ways such as with food that might otherwise have been impossible to
34 HIDDEN DEPTHS
access alone. Common chimpanzees who collaborate to hunt monkeys may
not be closely related (though sometimes will be); however, their eorts in
collaborating ‘pay o’ in their share of the proceeds.
One more complex way in which helping can pay o is when favours are
specically remembered and returned at a later date, eectively following
the tactic to ‘help someone who has helped you before’ or reciprocal altru-
ism. Returning favours (or ‘direct reciprocity’) makes it possible to translate
limited help in the present into help in the future, when it might be desper-
ately needed, and to develop mutually benecial collaboration even where
the individual beneting does not carry your genes. Reciprocity is even
more cognitively complex than simply helping any individual in need, as the
individuals themselves and the favours they rendered need to be remem-
bered. However, direct reciprocity avoids ‘wasting’ help that might not be
returned and allows pairs of individuals who are not kin to get help from
each other when in need (and be prepared to provide it). This type of ‘tit-
for-tat’ reciprocity is recorded in highly social animals who can be altruistic
to close peers, including coyotes (Canis latrans) (Romero and Aureli 2008),
rats (Dolivo, Rutte, and Taborsky 2016) and vampire bats (member of the
subfamily Desmodontinae) (Carter and Wilkinson 2015), and is particularly
common in primates, as in ‘tit-for-tat’ grooming, for example. Favours can be
remembered for several months in chimpanzees (Schino and Aureli 2010),
for whom such helping, whilst limited to ‘low-cost’ eort, includes not only
sharing food or helping instrumentally (to achieve a goal) but also in tak-
ing risks to help out others in conicts (Engelmann, Herrmann, and Toma-
sello 2015). Favours need not be explicitly remembered as discrete events
but rather as a pervasive inuence reecting how each partner feels about
(and feels sympathy towards and wishes to help) the other. Remembering
of favours, and helping in return, uses dierent brain circuitry and hormo-
nal responses from caring-based altruism (Marsh 2019). As we shall see in
Chapter 3, remembering favours and making judgements about the pro-
pensity of others to act in our interests is an early basis for relationships
based on trust and emotional commitments to another’s wellbeing.
Whilst kin-based helping, mutualistic helping and reciprocal helping are
explained through evident benets, not all helping in social animals has any
direct or indirect ‘pay o’ in such terms. Highly social animals are sometimes
emotionally motivated to help non-kin who may never help them in return.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 35
Generalised reciprocal altruism, helping others if you yourself have been
helped, was thought to be restricted to humans, but has, however, been
recorded in species such as rats (Dolivo, Rutte, and Taborsky 2016), vampire
bats (Carter and Wilkinson 2015) and marmosets (Burkart et al. 2007). Work-
ing dogs (Canis familiaris or Canis lupus familiaris) also tend to help each
other when they themselves have been helped and without expecting any
direct reward (Gfrerer and Taborsky 2017). It may be that sometimes a more
generalised tendency to help others in one’s group pays o by helping the
survival of the whole group in contrast to others (group selection) or in less
direct ways (Taborsky, Frommen, and Riehl 2016). In vampire bats, a willing-
ness to donate blood to unrelated individuals who would otherwise starve if
they were unsuccessful at nding food increases the likelihood of survival of
the group in general (Carter and Wilkinson 2015). Equally, a tendency to help
vulnerable group members in need may, by necessity, be so cognitively gen-
eral as to be expressed in many dierent situations. Many dierent mammals
adopt infants of other species, responding as if they were their own, and
adult male chimpanzees have been recorded ‘adopting’ unrelated orphan
infants, for example, with no clear benet to themselves (Boesch et al. 2010).
At various points in our evolutionary history, any or all of the mechanisms
described above will probably have had important selection pressures on
human emotional motivations towards altruism. There may also be selec-
tion pressures and processes unique to humans. Sexual or mate selection
Type of helping
behaviour
Basis of behaviour Example
Kin-based altruism ‘Help your relatives’ Shared parenting in
wolves
Mutualistic altruism ‘Help with a task which
benets everyone’
Hunting in chimpanzees
Reciprocal altruism ‘Help someone who has
helped you before’
Chimpanzee returning a
favour of food, grooming
or defence
Generalised reciprocal
altruism
‘Help someone if someone
has helped you’
Domestic dogs who work
together
Table 1.1: Dierent types of helping behaviour according to evolutionary
drivers.
36 HIDDEN DEPTHS
can inuence the evolution of emotional capacities, for example. Generosity
seems to confer advantages in nding a mate, with more generous people
generally rated as physically more attractive (Zhang et al. 2014), as well as
tending to have more children (Eriksson et al. 2018). There has even been
speculation that selection for partner altruism became so important in our
evolutionary past as to reach ‘runaway’ levels (where the trait is so extreme
as to endanger survival; Nesse 2009). Our tendencies to heroism may, like
the peacock’s tail, be a price to pay for attracting a mate. As we shall see in
Chapter 3, there also seem to be social benets to being someone that oth-
ers trust and having a ‘good’ reputation that make a tendency to compas-
sion and generosity worthwhile in a more general social context. There may
also be other complex processes at work. The evolution of human altruism
may have depended on the ‘policing’ of cheats, for example, who might oth-
erwise exploit naïve altruists (Egas and Riedl 2008; Fehr and Gächter 2002).
Moreover, there are good arguments that culture itself plays a key role in
how our emotional capacities have evolved. Humans become independent
of the physiological limits of their bodies on where they survive, such as
by tools or clothing or re, by around a million years ago (Mondanaro et al.
2020) and the importance of how we learn and how we t in has also had
an important inuence on how we involved (Heyes 2020). We might never
entirely disentangle the relative inuences of these dierent mechanisms,
but we can at least hope to gain important insights into how these factors
played a role in how we feel today and potential stages in the evolution of
our caring emotions.
Animal comparisons: stages in the evolution of human empathy,
compassion and generosity
Studies of animal behaviour do not just reveal interesting examples of
empathy, responses to distress or helping. They can provide important
insights into how human emotional motivations may have emerged.
Studies of our nearest living relatives, chimpanzees and bonobos, have
been a particular focus of attention. This is not surprising as the behaviours
of these apes can potentially give us important insights into the emotional
capacities that our shared common ancestor, living around 7 to 8 million
years ago, may have been likely to have possessed. This common ancestor is
often seen as the ‘starting point’ of our human evolutionary journey.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 37
Whereas most studies of cognition focus particularly on chimpanzees,
understanding the evolution of our emotions demands considering more
distantly related animals. There are ways in which distantly related but
highly interdependent animals show emotional capacities and behaviours
that are more similar to humans than those of other apes, suggesting that
human evolution has been more complex than any straight line we might
draw between chimpanzees and ourselves.
Comparing non-human apes and humans: emotional capacities and
helping behaviours of human ancestors 7 to 8 million years ago
It might seem rather odd to compare ourselves to other apes. However, such
comparisons help us to understand the most signicant transformations
that have taken place in our own evolutionary past.
There is a certain inescapable human-like quality to some of the social rela-
tionships we see in our nearest relatives. Apes in general, and chimpanzees
and bonobos in particular, are highly social animals, spending a lot of time
resting and grooming each other (Figure 1.4). Grooming releases positive
opiates, rearms alliances and helps negotiate their roles in a complex
dominance hierarchy, with touch showing similar eects in humans (Suvile-
hto et al. 2019). Further, being part of a large and complex social group is
associated with high degrees of social intelligence – you need to be socially
savvy to work out how to get along (Dunbar 2003). Many of the behaviours
we see in chimpanzees and bonobos that demonstrate their capacity for
empathy are familiar to us – such as contagious yawning, sensitivity to oth-
ers’ emotions, sympathetic concern, consolation behaviours and active
helping (Clay, Palagi, and de Waal 2018). Moreover, chimpanzees and bono-
bos are highly socially astute and intelligent, and show a remarkable cun-
ning, demonstrating behaviours that have even been compared to those
seen in human politics (de Waal 1998).
We can be reasonably condent, therefore, that a certain social astuteness,
with a sensitivity to others’ feelings and capacity to respond to distress, was
already present in the last common ancestor between ourselves and other
apes. Of course, chimpanzees and bonobos followed their own evolutionary
pathway since the split between their lineage and our shared ancestor liv-
ing around 7 to 8 million years ago, and many features of their thinking and
38 HIDDEN DEPTHS
social relationships must have been ‘derived’, that is, developed, during this
period of separation. Moreover, chimpanzees and bonobos followed dis-
tinct evolutionary pathways from around 2 to 3 million years ago and devel-
oped distinctive features after the split (discussed in Chapter 7). On a broad
level, their shared capacities to read others’ emotions and motivations, to
respond to distress, and to navigate complex social worlds nonetheless give
us some important insights into how our distant ancestor may have been
able to think and feel.
Of course, we are also vastly dierent from any chimpanzee or bonobo.
In many ways, comparing ourselves to non-human apes can seem rather
bizarre when we possess so many emotional and social traits that seem to
mark a vast gulf between ourselves and our nearest living relatives. Love,
poetry, imagination, complex beliefs and ideologies, and abilities to under-
stand abstract concepts or communicate in complex ways and understand
Figure 1.4: Chimpanzees grooming. Like humans, chimpanzees are intensely
social creatures. Grooming releases positive opiate based hormones and
is the main means by which chimpanzees and bonobos arm and nego-
tiate social bonds. Chi King, CC BY 3.0, via Wikimedia Commons: https://
commons.wikimedia.org/wiki/File:500px_photo_(188689963).jpeg.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 39
philosophical debates are but some of the many apparently fundamental
distinctions that divide us.
The marked dierences between ourselves and other apes in emotional
capacities and behaviours are important, however, and perhaps more inter-
esting than the similarities. If we can take them apart into some of the key
constituents, they tell us about the important transitions that must have
taken place after our lineage split from other apes. In fact, whilst many
of the ‘golden barriers’ supposedly separating humans from other apes
have broken down over the past decades, it is in the realm of emotional
sensitivity, empathy and altruism that we perhaps see the most marked dis-
tinctions. If we can begin to understand what transformations have taken
place, and why changes in emotional capacities might have been impor-
tant, our understanding of what was signicant about our human evolu-
tionary past may also change.
It seems obvious, but human motivations to help others are more in-depth
and more extensive. At an intimate level, we routinely respond to the needs
not only of our own infants but also our partners and families and friends.
Moreover, whilst chimpanzees’ infants are cared for almost solely by their
mothers, fathers often play a signicant role in parenting in human societies,
with grandparents and wider kin, and even friends, also playing an impor-
tant part. Beyond this intimate scale, we respond to the needs and feelings
of friends, wider social groups and even distant strangers. Chimpanzees are
predominantly self-focused, only rarely reaching out to console others, or to
share food. Whilst humans have been characterised as hypercollaborators
(Tomasello 2014), the rigid hierarchies of chimpanzees are based on com-
petition, with only rare collaboration. Our emotional sensitivities to others’
feelings and our level of emotional connection are also far greater. We can
identify others’ feelings from even the slightest of facial expressions, indicat-
ing emotions from joy and fear to bewilderment and surprise. On the other
hand, chimpanzees, in particular, are far less aware of how others feel. They
are less sensitive to faces and instead pay more attention to body postures
(Clay, Palagi, and de Waal 2018). For chimpanzees, being powerful is more
important than being sensitive. Moreover, we respond empathetically to a
far greater range of situations and vulnerabilities. We respond to not only
vulnerable young but also vulnerable adults we know, vulnerable adults we
do not know, entirely dierent species (discussed in Chapter 6) and even
40 HIDDEN DEPTHS
apparently vulnerable objects that seem to need our help and nurturance
(discussed in Chapter 7).
We are also far more socially astute. We identify others’ motivations with
remarkable accuracy from the slightest of facial expressions, and are nely
tuned to others’ distress (Grossmann, Missana, and Krol 2018; Marsh 2019).
This astuteness combines with empathy and an understanding of others’
minds to produce many apparently uniquely human feelings, such as grati-
tude or awe, guilt, pride or shame. Gratitude, for example, plays a key role
in inspiring generous behaviour, which cascades along networks of social
interactions and, moreover, makes people more emotionally resilient. Grati-
tude seems to be a uniquely human emotion, depending on sucient cog-
nitive empathy to accurately interpret whether someone has selessly acted
on our behalf. It is only late in childhood (around 11 years old) that we start
to feel and express gratitude (Emmons and McCullough 2004). Gratitude is
inuenced by our biology (vanOyen Witvliet et al. 2018) but also profoundly
aected by our sense of attachment to our caregivers (discussed in Part 2),
as well our culture, experience and deliberate choices (Mendonça et al.
2018). Other complex human emotions, such as awe, are equally dependent
on both emotional and cognitive capacities.
Psychological experiments have illustrated that important dierences
between ourselves and other apes emerge in early human childhood. Of
course, we do not all develop at the same rate, and dierences in our herita-
ble sensitivities to others’ distress make up the very variability on which evo-
lutionary changes work (Marsh 2019). Nonetheless, general developmental
changes are common to most of us. At only seven months old we will show
attention to fearful faces, with altruistic tendencies emerging by around
14 months (Grossmann, Missana, and Krol 2018). By only two years old, we
will already show strong motivations towards altruism and a willingness to
help others, and, moreover, more sophisticated helping behaviour than any
adult ape (Tomasello 2014; Warneken and Tomasello 2007); see Table 1.2.
How these marked dierences in helping behaviours emerge through our
infancy and childhood gives us some particularly useful insights into the
complex relationship between social thinking skills, and emotional moti-
vations and the potential stages through which our ancestors may have
passed en route to being human.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 41
As humans, we have exceptional capacities for anticipating others’ needs.
Even as young infants, we are more willing to help others and far bet-
ter able to anticipate the needs and goals of someone whom we wish to
help. Indeed, the most obvious dierence in helping that we might notice
between human infants and non-human apes is that infants can give unso-
licited help (without explicit cues or demands). Unsolicited help (i.e. help
in response to a need but without a cue being provided) is extremely rare in
apes. Apes will typically help someone reaching for an object (Warneken
2016; Warneken 2018) and chimpanzees can even, in some situations,
understand another’s goal and adapt their helping towards it (such as
selecting the appropriate tool an individual needs for a task to give to them;
Yamamoto, Humle, and Tanaka 2012). However, even chimpanzees tend to
only specically act on a cue that help is needed (Warneken 2016). Chimpan-
zees will, for example, (sometimes) respond to another’s hunger or desire
for food when they overtly beg, such as by reaching out towards the food,
but not foresee that an individual may need food or give them food because
they are aware that they do not have any. Human infants will, in contrast,
infer what help is needed unsolicited. If someone loses something to a bully,
yet remains stoic and shows no sign of distress, for example, we will want to
comfort them from around 18–24 months of age, appreciating that the situ-
ation is one in which we ourselves will be likely to be upset (Vaish, Carpen-
ter, and Tomasello 2009). By two years old, we will tend to give something
to someone who is ‘empty-handed’ without any cue or request (Warneken
2018). Unsolicited helping of this kind demands aective empathy (an
emotional response to another’s situation) as well as a sophisticated level
of perspective-taking. Debates exist over the extent to which non-human
apes, and chimpanzees in particular, possess theory of mind (the ability to
understand what another individual is thinking) (Call and Tomasello 2008).
However, whether non-human apes possess a true theory of mind or not, it
is clear that at one and a half to two years old we show a more sophisticated
mental model than any adult ape of what others think and believe, and use
this when helping others.
A further signicant dierence is that, even as young infants, we can direct
our help towards long-term goals, rather than immediate desires, something
not seen in any other animal. If adults wanting a cup of water ask for a cup
that an infant knows will leak, then three-year-olds will pass the adult not
the cup they ask for but one without a hole in order that they can drink
42 HIDDEN DEPTHS
Helping
behaviour
Primate species Example Human
develop-
ment
Example
Consolation Apes, monkeys
and some highly
social mammals
Adult chim-
panzees
hugging the
loser of a ght
Infants in
their rst
year
Touching
or hugging
someone in
distress
Targeted/
situational
helping
Apes, some
monkeys and
some highly social
mammals
Adult chim-
panzees pass-
ing someone
an object that
is out of reach
Infants
from one to
two years
old
Passing an
object that
has been
dropped
Unsolicited
helping
Rare – bonobos in
an experimental
setting
Helping
another
individual gain
food without
an explicit clue
Infants
from two
years old
Giving a toy
to some-
one who
is ‘empty-
handed’
Helping
towards
long-term
needs or
goals
Rare – potentially
seen rarely in
some types of
collaborative
hunting
Hunting in Taï
chimpanzees,
where certain
individuals
assume par-
ticular roles
Infants
from three
years old
Passing a cup
without a
leak to drink
water, even
when asked
for a leaky
cup
Morally
discriminate
helping
Not recorded –
(though apes
preferentially help
allies according
to remembered
favours)
— Infants
from two to
three years
old
Helping a
‘nice’ adult in
preference to
a ‘mean’ one
Table 1.2: Stages in empathetically motivated helping seen in apes and
human infants.
eectively from it (Martin and Olson 2013). Making a distinction between
what is requested and what is actually needed is cognitively complex, but
particularly signicant in terms of being able to act in the best interest of oth-
ers. In this case, infants have identied the ultimate long-term goal and what
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 43
will achieve that goal, they have also been motivated to help and, moreover,
they have overridden a direct request, putting the best interests of another
above pleasing them. Even as infants, we show sophisticated abilities to
coordinate dierent actions towards an end goal, such as when one individual
performs one task and another does something else, both contributing to
the shared goal (Warneken 2018). To do this we use both a mental represen-
tation of the end goal and one of how dierent activities contribute to it,
combined with our notable emotional motivations to help.
Both unsolicited helping and helping towards long-term goals might appear
simple but they require both aective concern for others, and complex cog-
nitive abilities, and both types of helping inuence the type of collaboration
which can take place. Without unsolicited helping, someone who is ill or
injured and may not be able to make an explicit request for help is likely to
perish, for example. Likewise, helping towards an end goal through dier-
ent activities opens up possibilities for new types of collaboration.
It might seem a little bizarre to compare human infants with fully adult chim-
panzees. However, the distinctions that we see between helping behaviours
in fully developed adult chimpanzees and those of young human infants
give us some important insights into potential stages in the human evolu-
tionary past. Our own development of children does not, of course, in any
way replicate the way in which we have evolved, but it does give us some
insights into the possible sequence of changes in emotional and cognitive
capacities that might have taken place in the past and how they may have
inuenced social relationships and communities.
Actively helping others depends on both social understanding and emo-
tional motivations (or social cognition and aective cognition).
Cognitive empathy
It is our social thinking skills or cognitive empathy (broadly speaking, ‘theory
of mind’ abilities; Dunbar 2003) that has attracted the most research atten-
tion. Though our understanding of others’ thoughts and that of others’ feel-
ings inform each other, they are distinct, and are related to dierent brain
functions (Eres et al. 2015; Stietz et al. 2019; Watanabe et al. 2014). Cognitive
empathy helps us to understand others’ beliefs about us (for example, our
44 HIDDEN DEPTHS
reputation in their eyes), whilst aective empathy helps us to emotionally
relate to how they feel.
In simple terms, comparisons between other apes and human infants illus-
trate that, in our development, we increasingly outsmart other apes in terms
of our abilities to help using our cognitive empathy, that is, by taking others’
perspectives and using our complex executive functions to better under-
stand others’ needs, as well as how we can help. Certain key stages seem to
be evident (see Table 1.2 and Figure 1.5).
Aective empathy
The evolution of our emotional cognition through aective empathy (or
emotional empathetic response) has received far less research attention
than our social thinking skills. This is perhaps, at least in part, because
emotional motivations are often seen as ‘woolly’ and dicult to research.
Figure 1.5: Increasingly complex cognitive empathy seen in humans com-
pared to some other social animals. Penny Spikins, CC BY-NC 4.0.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 45
Moreover, it is hard to ignore the possibility that we also feel rather more
ambiguous about whether our emotional capacities are ‘something to be
proud of’ or something more of a weakness (as discussed in the introduc-
tion to this book).
There is a more complex issue, however. A further complexity is the lack
of a clear link towards our nearest relatives. Considering potential stages
in the evolution of our emotional motivations to help others presents us
with a rather dicult and surprising paradox. Chimpanzees are remark-
ably self-focused and it is other far more distantly related animals who
show a much more human-like ability and tendency to connect to others’
feelings, respond to others’ needs and to help when required. This seems
counterintuitive. Chimpanzees and bonobos are the animals that are most
closely related to us. Yet other, much more distantly related species behave
in more human-like ways where altruism towards members of the group
are concerned. These include species such as distantly related primates
(as discussed in the introduction to this chapter) and even more distantly
related animals such as social carnivores. Capacities that link more to wolves,
hyenas or squirrel-like monkeys seem not to be so elevated as are more ana-
lytically social thinking skills.
This paradox tends to receive little attention (it is inconvenient, after all).
Rather than our nearest relatives, we nd that some of the most distantly
related primate species to ourselves, New World monkeys of the family Calli-
trichidae, are those who seem to connect most deeply to those around them
and are the most aectionate and altruistic to their peers. As we have seen
in the Introduction, these monkeys, including marmosets and tamarins, are
tiny, and remind us more of squirrels than chimpanzees. However, they
are pair-bonded, and collaborate to raise ospring, with infants cared for not
only by parents but also by other helpers (Rapaport 2011). As a result of this
close interdependence, they respond much more widely to others’ needs
and show a much greater aective empathy than do most other primates.
Marmosets and tamarins, for example, show not only a concern for fairness
(Yasue et al. 2018) and capacities to share but also loyalty to their mate and
great investments in eorts in shared care of ospring. Certain brain areas in
males are active when recognising their mate (Bales et al. 2007), associated
with pleasurable hormonal responses due to the release of the hormones
46 HIDDEN DEPTHS
oxytocin and dopamine, as we also see in humans (Abraham and Feldman
2018; Feldman 2017). Many argue that, in their willingness to be generous
and in the sharing of care, they are a better analogy for early humans than
are much more closely related chimpanzees (Burkart and Finkenwirth 2015;
Erb and Porter 2017).
Pair bonding has arisen in many very distantly related species, and there
may be dierent selection pressures and ecological and social situations
which make mutual investments in ospring worthwhile. Amongst New
World monkeys, the wide distribution of females, and threats to the sur-
vival of ospring looked after by only one parent, may have been particu-
lar factors in selection pressures on males, in particular to be much more
emotionally invested in their mate and ospring. Cooperative breeding
increases in harsher environments (Smaldino et al. 2013). Human pair bonds
and, moreover, collaborative infant care may have been a response to eco-
logical demands of challenging environments, though responses to particu-
lar social structures may also have been important (Rooker and Gavrilets
2016). Pair bonding and collaborative parenting are likely to have played a
signicant role in changes in emotional dispositions in humans, as well as
allowing increasingly vulnerable young with a larger brain size to be raised
successfully (Burkart, Hrdy, and van Schaik 2009; Hrdy 2011).
Collaborative defence also plays a role in increasing emotional investments
in others’ wellbeing and willingness to take risks on behalf of the whole
group in some, more distantly related, mammals. Meerkats, for example,
collaborate to raise ospring and defend their group, and to teach valuable
skills to the next generation (Rilling 2011). Many argue that collaborative
defence evolved after the split with other apes, as early humans moved into
more open environments with many predators (Hart and Sussman 2011).
However, even more distantly related animals seem even more similar to
humans in terms of their motivations to help others in their group, to share
what they have and to respond to their needs.
Though we are apes, there is good reason, in terms of our emotional motiva-
tions, to see similarities between ourselves and more distantly related mam-
mals – social carnivores such as wolves and lions (Thompson 1975).
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 47
Social carnivores help others within their group much more extensively
than do apes – as we have seen above, highly social mammals collaborate
to look after their ospring, hunt together, share food and even in some
cases provision those who are sick or injured. Social carnivores are highly
interdependent, depending on each other for their basic food necessities,
and sharing infant care, as well as showing each other frequent gestures of
warmth and aliation. From modern hunter-gatherers to people in modern
industrialised societies, like social carnivores (and unlike apes), we look after
others’ ospring, depend on shared food and care for the ill and injured.
Wolves and hyenas may have a bad reputation for being erce and
aggressive, but their willingness to be generous and emotional motiva-
tions towards altruism within their own group are remarkable (Jouventin,
Christen, and Dobson 2016). Groups of hyenas may operate in ways that
share similarities with highly collaborative early humans. Spotted hyenas
collaborate between kin and non-kin to hunt and to defend their group
from competitors or predators, for example (Smith et al. 2012). Despite their
far greater separation from humans in phylogenetic terms, they can poten-
tially contribute to our understanding of the evolution of human generosity
and compassion (Schaller and Lowther 1969; Smith et al. 2012).
Wolves are also a particularly good example of highly intelligent mammals
who have strong emotional connections to others in their living group and
help each other in remarkably costly ways (Smith et al. 2012). As social car-
nivores, wolves hunt together, risk their own lives to defend others, willingly
share food, care for each other’s ospring and can also care for the sick and
injured, regurgitating food as they would for pups. Thus, empathetically
motivated helping within any group of wolves is far more costly than that
seen within groups of chimpanzees. Like humans, wolves also thrive on fre-
quent gestures of care and aliation between each other (Figure 1.6). They
have evolved to be highly sensitive and responsive to each other’s emotions,
displaying their own facial and body expressions (Beko 2002), and some
traits of a theory of mind (Horowitz 2011). Like other apes, and humans, they
also display yawn contagion, a response related to empathising (Romero et
al. 2014). They also have large brains, low levels of sexual dimorphism and a
sophisticated social cognition that exceeds that of their near relatives who
do not need to collaborate to survive (Borrego and Gaines 2016). As we shall
48 HIDDEN DEPTHS
see in Chapter 7, it may be no surprise that the animals that we choose to
share our lives with are descendants of wolves, rather than closer primate
relatives. Social carnivores are far happier to share our social rules, form
close attachments with us, and see us as part of their close-knit social group.
Perhaps surprisingly, wolves are not even the most social of canids and their
relatives. African painted wolves (Lycaon pictus) are even more strongly col-
laborative and interdependent. They are even more hyper-carnivorous, and
so more dependent on collaborative hunting, than wolves, and routinely
support and provision their ill or injured pack members. African painted
wolves often attract less interest or attention than other canids because
they have less expressive facial expressions, yet they are no less expressive
of their feelings or attentive to those of others. It is simply that, on their
particular evolutionary branch, emotional communication occurs more
through vocalisations, body postures and ear positions (Creel and Creel
Figure 1.6: Wolf photographed at Polar Zoo, Norway. Wolves show remark-
able generosity to others in their pack – taking risks on others’ behalves,
sharing food, and displaying strong, aectionate and often playful alia-
tive emotions to each other. Johannes Jansson/norden.org, CC BY 2.5 DK,
via Wikimedia Commons: https://commons.wikimedia.org/wiki/File: Varg
_fotograferad_pa_Polar_Zoo_Norge_(15).jpg.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 49
2002). Their level of interdependence can bring disadvantages, with African
wild dogs being threatened with extinction since their highly collaborative
care for young means that they depend on more than a single breeding pair
to successfully bring up ospring. This issue of dierent types of communi-
cation, and the eects of high levels of interdependence on vulnerability to
extinction, is also relevant within our own evolutionary past, particularly in
contrast with Neanderthals (Chapter 8).
No one would suggest that we are just like wild canids such as wolves; how-
ever, these highly social and interdependent species may give us a far better
insight than our closest relatives into how human generosity, compassion
and empathy evolved. It goes without saying that humans show additional
extended capacities in responding altruistically in more extensive ways to
non-kin and strangers, to other animals, and even to inanimate objects
(Figure 1.7). However, highly collaborative species and those that parent
Figure 1.7: Increasingly extensive aective empathy seen in humans com-
pared to some other social animals. Penny Spikins, CC BY-NC 4.0.
50 HIDDEN DEPTHS
collaboratively and appear bonded tend to give us a better indication of
intermediate stages in the evolution of human social emotions.
Evolutionary pressures on emotional motivations
How could distantly related social mammals be more similar to us in terms
of emotional motivations than those that are far more closely related?
One answer may lie in a combination of the inuence of ecology on selec-
tion pressures acting on social behaviours and the speed with which ten-
dencies to particular hormonal responses can change in evolutionary time.
The relationship between hormones and behaviours is complex, and car-
ing behaviour, for example, is inuenced not only by inherited genetics but
also by factors that inuence the expression of particular genes (epigenet-
ics), personality, experience and culture (see Figure 1.8; for a more detailed
discussion, see Marsh 2019). However, subtle evolutionary changes in
hormone systems can have far-reaching eects on emotional motivations
and behaviour (discussed in more detail in Chapter 7). Moreover, there are
Figure 1.8: Some of the factors associated with variations in caring motiva-
tions and behaviours. Penny Spikins, CC BY-NC 4.0.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 51
common patterns across species in factors inuencing care, and how these
inuence neuroendocrine function.
Heritable changes that inuence the production of particular hormones
have a key role to play in directing dierent types of social behaviours. Evo-
lutionary changes in bonding hormones such as between dierent species
have far-reaching eects on emotional responses and caring behaviours
(Carter et al. 2008).
Changes in genes that aect oxytocin production or uptake is one example.
As we have seen, mammals all share a nurturing response to our young that
is mediated by oxytocin. This means that mammalian mothers feel a similar
sense of warmth when nurturing their young, as we do. Their empathetic
responses to their infant’s needs are rewarded by oxytocin release (Decety
et al. 2012). Oxytocin is also key to pair bonding across a range of social
mammals. It mediates the feel-good response many men feel on seeing
their partner’s face (Scheele et al. 2013), and pair bonding in a wide range of
species such as marmosets (Smith et al. 2010) and prairie voles (Carter et al.
2008). Oxytocin also has an important role to play in collaboration beyond
maternal/paternal and pair bonds. Oxytocin is implicated in peaceful group
associations within mammals in general (Romero, Onishi, and Hasegawa
2016) and is part of hormonal systems, also including hormones such as tes-
tosterone (discussed in Chapter 6), which promote collaboration in primates
and humans (Trumble, Jaeggi, and Gurven 2015). Sharing food, including
with non-kin, is mediated by oxytocin in wild chimpanzees, for example
(Wittig et al. 2014).
Articially changing levels of oxytocin has particularly interesting eects
on social behaviour. In dogs, elevated levels of oxytocin increase social
play (Romero et al. 2015), for example, and, in meerkats, elevated levels of
oxytocin increased social teaching behaviours (Madden and Clutton-Brock
2011). Many social behaviours in mammals, beyond nurturance such as play
(Romero et al. 2015) and social learning (Madden and Clutton-Brock 2011),
are also inuenced by oxytocin-mediated social bonds. In humans, oxytocin
also plays an important role across many dierent human social bonds, from
close romantic relationships to family bonds (Ten Velden, Daughters, and
De Dreu 2017). Articially increasing oxytocin increases interpersonal trust
52 HIDDEN DEPTHS
(Baumgartner et al. 2008; Kosfeld et al. 2005), generosity (Zak, Stanton, and
Ahmadi 2007) and gratitude (Algoe and Way 2014), and oxytocin is also
implicated in empathy for strangers (Barraza and Zak 2009). Mutual gazing
increases oxytocin levels between humans and dogs (Nagasawa et al. 2015).
Even quite subtle changes in these hormones have far-reaching eects on
emotional responses and social behaviours, including caring behaviours.
The eects of evolutionary changes in hormonal responses can be
complex. There is, for example, a darker side to the group altruism brought
by oxytocin, once dubbed the ‘cuddle hormone’. Elevated levels of oxy-
tocin can also enhance motivations towards defending an in-group against
out-groups that appear threatening (De Dreu et al. 2011). For this reason,
oxytocin has been seen as a hormone that makes people more sensitive to
social clues, rather than more prosocial per se. It is associated with stimu-
lating motivations to ‘tend and defend’ one’s loved ones, even where the
defence may involve aggression (Ne’eman et al. 2016). In many ways, oxy-
tocin is more about emotional commitments, and support of particular
loved ones, rather than being friendlier or simply more altruistic. There is
some evidence that, for females, oxytocin can promote more of a ‘tend and
befriend’ response than ‘tend and defend’, promoting motivations to reach
out to develop stronger relationships and so strengthening, rather than
disrupting, networks of relationships (Taylor et al. 2000). Whether these
responses are cultural or genetic remains to be resolved but, evidently, feel-
ings of warmth towards certain others, stimulated by oxytocin, can aect
how we actually behave in diering ways. As we shall see in Chapter 6, the
impact of changes in testosterone are equally complex.
Subtle changes in inherited genetics that inuence hormones like oxytocin
(such as oxytocin receptor densities in the brain) can have quick and far-
reaching eects on emotional responses and social behaviours. Many spec-
ulate, for example, that hormonal changes in oxytocin and in vasopressin
are likely to have been key to changes in the role of fathers in infant devel-
opment in human evolution (Abraham and Feldman 2018; Feldman 2017)
and other changes in these hormones, later in human evolution, may have
been important in changes in intergroup tolerance (discussed in Part 2).
We can be condent that changes in hormonal responses to particular
situations played a key role in changes in human emotional responses.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 53
However, in the absence of directly identifying genetic signatures related
to particular hormones (discussed for later human evolution in Chapter 7),
precisely which hormones, and how they may have changed, remains an
area of debate. Recent research suggests a related opioid β-endorphin may
be important in maintaining long-term relationships through feelings of
trust, calmness and relaxation in the presence of long-term mates, kin and
allies, for example (Pearce et al. 2017). Crosstalk or an intimate relationship
between oxytocin and dopamine in striatum, combining motivation and
vigour with reward-seeking social focus, may also be important (Feldman
2017: 80). Whilst oxytocin provides the soothing and tranquillity necessary
for bond formation via its eects on the hypothalamic–pituitary–adrenal
(HPA) axis, dopamine provides a sense of anticipated reward and pleasure,
and inuences drives to reconnect and act to maintain long-term bonds,
potentially important in early human origins (DeLouize et al. 2017). Changes
in other hormone systems are also implicated in increasing collaboration.
Pair-bonded mammals, for example, typically show a reduction in testoster-
one, as eorts in competition for mates become less worthwhile (Trumble,
Jaeggi, and Gurven 2015). However, much as oxytocin plays several roles,
testosterone can play a role in in-group collaboration ‘against’ out-groups or
in defence. The precise nature of hormonal changes promoting greater col-
laboration in dierent species is likely to have been subtly dierent.
Ecological changes putting selective pressures on increased collaboration,
whether this be due to a need to defend against predators, to collaborate
to exploit resources (such as collaborative hunting in social carnivores)
or to collaborate in childcare, can exert selection pressures on hormonal
responses and, in turn, inuence changes in typical emotional responses to
vulnerable infants or other group members.
Social carnivores illustrate this eect. They need to work together in order
to survive. This is because social carnivores typically have to hunt collabo-
ratively to be able to tackle prey that would be impossible for individuals
alone, collaborate to defend themselves from predators that might other-
wise overcome any individual in isolation, share food and share the care of
vulnerable young to give their ospring the best chance of survival. All of
these behaviours involve extended caring responses beyond maternal infant
bonds and group aliations. As a result, selection pressures have acted on
existing mammalian empathy and other traits present in the ancestors of
54 HIDDEN DEPTHS
social carnivores to create neurological and hormonal responses, not only to
one’s own young but also to other adults in the group, and other ospring
(Decety et al. 2016). Emotional motivations to help others in the group ‘pay
o’ because, over the long term, such eorts improve evolutionary success.
This is most obviously the case where group members are predominantly
kin who carry shared genes; however, altruism towards group members can
pay o even in groups including or made up of non-kin where each indi-
vidual is important to group survival (and helping them improves one’s own
survival chances) (Frank and Linsenmair 2017); see Figure 1.9.
Selection pressures act most particularly on neuroendocrine responses,
which may change relatively rapidly, often responding far more quickly
than changes in hard skeletal morphology or more complex areas of cogni-
tion. Where sharing behaviours, caring or generosity pays o, therefore, we
Figure 1.9: Selection pressures acting in highly collaborative social mam-
mals, and particularly social carnivores, towards the extension of empathy
to all group members. Penny Spikins, CC BY-NC 4.0.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 55
expect brain and communal responses to favour individuals more prone to
be generous or compassionate to other group members. For this reason,
in ecological situations in which individuals are highly dependent on other
members of the group for their own survival, responding to others’ needs
and being prepared to give generously and to share start to feel pleasur-
able. This mechanism is likely to have been as signicant for early humans
as for any other social collaborative animal. As Allen explains, ‘generosity
produced pleasurable feelings in certain humans – and thus made those
humans more likely to be generous again – they thereby became the ones
who are more likely to survive’ (Allen 2018: 11).
Implications for the evolution of human empathy,
compassion and generosity
Pulling the above together, we can see that comparisons both with our
nearest living relatives, chimpanzees and bonobos, and with more distantly
related species that share human emotional motivations towards vulnerable
infants and group members, suggest that certain key distinctive transforma-
tions in human empathy, compassion and generosity, and the strength of
our emotional connections, took place during the last 7 to 8 million years
of human evolution.
In very simple terms, we can imagine these changes as additional ‘shells’ of
particularly human cognitive empathy and aective empathy (Figure 1.10).
These particularly human capacities are not widely seen in our nearest rela-
tives, so are likely to have emerged after our split with other apes around 7
to 8 million years ago. These are, however, likely to have been inuenced by
contexts we share with other highly social animals, which place pressures on
Figure 1.10: Additional levels of uniquely human developments in aective
and cognitive empathy building on capacities shared with some social
animals. Penny Spikins, CC BY-NC 4.0.
56 HIDDEN DEPTHS
collaboration, as well as probably uniquely human selection pressures oper-
ating through culture, complex cognition or reputation (discussed in Chap-
ters 2 and 3). Ecological changes, or movements into new ecological niches
in which survival is based on group interdependence (e.g. for defence against
predators or when hunting dangerous animals), would have placed selective
evolutionary pressures on emotional responses to others’ needs, for example.
Of course, this characterisation is bound to be an oversimplication. More-
over, no one would pretend that we can summarise the complexities of
what makes being human distinctive, such as the depths of how we feel
about each other or our love or emotional connection, in such simple terms.
Nonetheless, an abstract model such as this may help us to understand
some of the potentially key stages to how our particularly human emotional
connections and caring motivations evolved.
Relatively subtle changes aective or cognitive empathy can have far-
reaching eects on social relationships and communities. Caring behav-
iours directed towards others’ infants or vulnerable adults have a signicant
impact on both infant survival and recovery from illness and injury, for
example. Abilities to think through helping towards long-term goals or
without particular requests also have signicant impacts on the complex-
ity of resource-seeking behaviours and sharing. Furthermore, concerns over
fairness and justice, and willingness to punish antisocial behaviour, provide
the basis for a transformation from competitive hierarchies in which the
strongest survive to egalitarian collaborative social systems based on inter-
dependence and give and take.
There is, nonetheless, a catch to any simplication such as this. It is always
tempting to see evolutionary changes and adaptations, particularly those in
humans, as a progression towards something better. However, we should be
wary of seeing ourselves as some pinnacle of progress (as discussed in the
introduction to this volume). We are simply just another unique species, no
matter how remarkable our caring responses and emotional connections
to others may be. We have to remember, rstly, that adaptations are always
compromises. There is a cost to complex cognitive processing in terms of
the costs of brain enlargement of the energetics of brain development,
and to emotional responses to care for others in terms of the individual
energetics of such care, as well as the emotional costs of responding to
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 57
others’ distress. As we discussed in the Introduction, our tendencies to care
deeply about our loved ones make us vulnerable, even as they make our
close group stronger. Our aective and cognitive empathy comes at a price.
Secondly, there will be options and branches even in our own evolution,
and dierent options of emotional responses that were neither better nor
worse (discussed in Chapters 8 and 9), many of which have failed to leave
traces visible today through often chance processes, rather than any simple
line to ourselves. If we want to get away from the idea that there was some
predetermined process that elevated humans, we have to better under-
stand these compromises and options.
Many questions remain.
It is dicult to explain the in-depth and extensive nature of human altruism.
Why might we, unlike other animals, be motivated to help strangers and to
respond to the distress of other species and even nurture inanimate pos-
sessions? Moreover, we cannot help but wonder when key transformations
took place and what happened. How far back can we trace distinctively
human motivations to connect emotionally to others and respond to their
needs? How signicant were these motivations in our evolutionary history?
And what types of selection pressures were particularly important in driving
the evolution of our unique emotional capacities?
Only by turning to the material record to provide clues to how human behav-
iour has changed over the last few million years, in Chapter 2, can we begin
to better understand why and how our most human emotions emerged.
Conclusions
Our gut feelings and emotional reactions play a key role when we react
with compassion or generosity to others’ needs, from giving blood to eve-
ryday acts of kindness. We rarely consider this biological basis to our emo-
tional connections, perhaps preferring to see ourselves as purely rational
beings, yet it is genuine emotional connections that form the basis for our
strongest bonds. This biological basis has emerged because of the complex
selection pressures acting on our ancestors, from long-distant early forms
of social mammals to more recent ape ancestors. Because of this, our near-
est living relatives, chimpanzees and bonobos, share many emotional and
58 HIDDEN DEPTHS
social characteristics with humans, and give us important clues as to the
emotional capacities of our last shared ancestor. However, neurobiological
changes can occur quickly in an evolutionary context, and subtle changes
can have far-reaching eects. Other social mammals who are more depend-
ent on each other for survival, and who share food, share infant care or col-
laborate to defend themselves from predators or nd food, can sometimes
be more human-like in their willingness to help each other. Some of the
most signicant changes in human social relationships and societies over
the last few million years may derive from subtle but important changes
in emotional motivations (aective empathy) and social thinking abilities
(cognitive empathy), some of which we see in other animals and some of
which are unique to humans.
Perhaps surprisingly, it is distantly related primates such as the marmosets,
discussed at the start of this chapter, or even social carnivores such as
hyenas or wolves who can give us important insights into the evolution of
our close emotional relationships to those around us. Whilst we may identify
changes in aective and cognitive empathy since our separation from other
apes, we would be wrong to conclude that such changes brought a certain
superiority over other species. Many of the changes taking place bring us
closer to other animals such as these rather than further away. Our social
lives within highly collaborative groups, the willingness to defend our kin,
share care for our ospring and look after the vulnerable, make us more
similar to many social carnivores, for example (explored further in Part 2).
By considering the material record for human behaviours (in Chapter 2), we
might begin to understand why and how these important transformations
took place in human emotional motivations after the split with other apes.
Key points
• There is a signicant biological basis to the building blocks of our emo-
tional connections in human empathy, compassion and generosity.
• Individual social behaviours are inuenced not only by our biologi-
cal responses but by other factors including our cognitive appraisal of
particular situations, personal experience and beliefs, social relation-
ships and culture as well as by specic circumstances.
THE EVOLUTIONARY BASIS FOR HUMAN EMPATHY 59
• Selection pressures towards altruistic motivations lead to several dif-
ferent forms, including kin-based altruism, mutualistic altruism, recip-
rocal altruism and generalised reciprocal altruism. All of these, as well
as uniquely human selection pressures, such as pressures to develop a
positive social reputation or specic mate selection pressures, are likely
to have been inuential in our evolutionary past.
• Comparisons with our nearest living relatives, chimpanzees and bono-
bos, can provide insights into the emotional and social capacities of our
last shared ancestor around 7 to 8 million years ago. They also provide
insights into key changes in aective and cognitive empathy that have
taken place during human evolution.
• More distant relatives of social mammals who depend on collabora-
tion for survival can provide us with analogies for human altruistic
motivations towards vulnerable infants, vulnerable adults and mates.
Our emotional connections are in some ways more similar to these far
more distantly related social mammals than to our nearest relatives.
• Subtle but important changes in human emotional responses to vulner-
able infants, adults and mates and in abilities to make long-term com-
mitments and be concerned with fairness and justice are likely to have
had far-reaching eects on the character of human social relationships
in the evolutionary past.
60 HIDDEN DEPTHS
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CHAPTER 2
Material Evidence: caring for
adult vulnerabilities
Abstract
What can archaeological evidence contribute to our understanding
of the origins of human empathy, compassion and generosity?
We have seen in Chapter 1 that our human capacity for compassion
and our tendencies to help others have an important evolved bio-
logical basis. Here, we focus on what the preserved material evidence
of early humans and their behaviours can contribute to our under-
standing of how our emotional motivations to help others emerged.
We particularly consider often-overlooked archaeological evidence
for care for adults made vulnerable by illness or injury. This evidence
demonstrates a deep past to human emotional motivations to help
those around them. Furthermore, changing emotional motivations
are a response to wider context and selective pressures, similar to
those also seen in some other social mammals. A critical appraisal of
evidence for responses to illness and injury suggest that signicant
changes in helping behaviour and responses to vulnerability may
(Abstract continued on next page)
How to cite this book chapter:
Spikins, P., 2022. Hidden Depths: the origins of human connection. Pp. 71–127. York:
White Rose University Press. DOI: https://doi.org/10.22599/HiddenDepths.c.
License: CC BY-NC 4.0
72 HIDDEN DEPTHS
have taken place around 2 million to 1.5 million years ago – around
the time of key ecological changes and a transition to a new hunt-
ing niche. Responses to vulnerability and motivations to help may
have been a central element to cognitive-emotional changes that set
humans on a track that is distinctive and much more interdependent
than that of other apes. Considering the archaeological evidence for
care allows us to add a time depth and an explanation for the model
of changes in cognitive and aective empathy outlined in Chapter 1.
An understanding of the potential signicance of care prompts fur-
ther questions, such as around dierent evolutionary pathways in
emotional motivations, the relationship between biology and cul-
ture in care for illness and injury, the extent of human dependence
on such care, and its signicance in terms of extended lifespans.
Nonetheless, it is clear that an extension of human empathy, com-
passion and generosity from at least 2 million years ago played a
much more signicant role in our evolutionary origins than is usually
accepted, prompting us to reconsider the driving factors leading to
human evolutionary success.
Following on from the signicance of interdependence, we consider
the formation of relationships based on emotional commitments
and trust, and the increasing importance of social reputation, in
Chapter 3.
(Abstract continued from previous page)
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 73
Introduction
Our image of our distant past often tends to be rather a brutish one. Even
if we no longer imagine thuggish cavemen wielding clubs and surrounded
by dinosaurs, we certainly assume that our distant past was a battle for sur-
vival in which there was no time for ill health, and few people were in any
way kind.
The archaeological evidence does not support this image. In fact, it paints
a very dierent picture. Whilst the infectious diseases that plague large and
settled communities were rare, people throughout the Palaeolithic period
(from the time of the earliest recovered stone tools, over 3 million years ago,
to the end of the last ice age around 10,000 years ago) frequently suered
general wear and tear on bones and muscles, as well as injuries sustained
hunting and gathering resources. Most skeletal material from that period
shows signs that people were commonly living with the eects of illness
and injuries. However, recovery from even severe injuries or illness, or at
least survival despite them, was common, suggesting willing care from
Figure 2.1: Left: Shanidar 1. Osama Shukir Muhammed Amin FRCP(Glasg),
CC BY-SA 4.0, via Wikimedia Commons: https://en.wikipedia.org/wiki
/Shanidar_Cave#/media/File:Shanidar_I_skull_and_skeleton,_c._60,000
_to_45,00o_BCE._Iraq_Museum.jpg. Right: Reconstruction of a Neander
thal male. Neanderthal Museum, Mettmann, CC BY-SA 4.0, via Wikimedia
Commons: https://commons.wikimedia.org/wiki/File:Homo_sapiens
_neanderthalensis-Mr._N.jpg.
74 HIDDEN DEPTHS
others for adults who could not care for themselves. This dierent picture
may help to reframe our ancestors as interdependent, and often vulner-
able, people whose emotional connections to each other were key to their
shared survival.
One famous skeleton, found in Shanidar cave in Iraq, illustrates particularly
well the extent to which evidence for caring behaviours has changed our
assumptions about the character of our ancestors. This particular skeleton,
Shanidar 1, or ‘Ned’, has been the subject of much debate about the emo-
tional dispositions of Neanderthals (Homo sapiens neanderthalensis) and the
extent to which they were kind or callous (see Figure 2.1).
Ned had certainly had a very rough life. He lived around 45,000–70,000
years ago and survived a remarkable level of injury and impairment. His
bones were excavated between 1957 and 1961, and demonstrated many
dierent injuries. Probably, as a young adult, he had suered a blow to the
left side of his face, resulting in blindness or only partial sight in one eye. He
also had a hearing impairment; a withered right arm, the lower part of which
had been lost after a fracture, and possible paralysis; deformities in his foot
and leg, leading to a painful limp; and advanced degenerative joint disease
(Crubézy and Trinkaus 1992: 411–12; Kent 2017; Trinkaus 1983; Trinkaus and
Villotte 2017; Trinkaus and Zimmerman 1982: 61–62). How he suered his
eye-watering range of injuries is not entirely clear, though there has been
speculation that he may have been injured in a rock fall.
What was remarkable about this individual was not his injuries themselves
but the length of time over which he had survived despite them. He had
been injured at least 10 to 15 years before his death, with the curvature of
his right leg compensating for injuries to the left (Trinkaus and Zimmerman
1982: 67–68). Yet Ned lived until he was aged between 35 and 50, relatively
old for a Neanderthal, despite his range of debilitating impairments. These
restricted mobility, ability to perform manual tasks, and perception (Spikins
et al. 2018). Solecki (1971), and later Trinkaus and Shipman (1993), argued
that he could not have survived without daily provision of food and assis-
tance. Trinkaus and Zimmerman even commented (1982: 75) that Nean-
derthals ‘had achieved a level of societal development in which disabled
individuals were well cared for by other members of the social group’. Aside
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 75
from Ned himself, there are many other cases suggesting care against the
odds. We now have a wealth of evidence for Neanderthal care, with more
than 20 cases of probable care for illness or injury recorded (Spikins et al.
2019). In many, it is clear from the severity of illness or injury and evident
lack of possibility of recovery that only genuine caring motivations rather
than any calculated reasons explain the help the injured received (Spikins
et al. 2018).
After his treatment in life, Ned was also carefully buried after death. He was
one of many Neanderthals who were either buried or given a specic mor-
tuary treatment (such as disposal in pits or clefts) at death (Pettitt 2013), the
meaning of which remains a topic of much debate (Pomeroy et al. 2020).
Ned seems to provide almost incontrovertible evidence for the emotional
motivations of Neanderthals, who seem to have cared deeply for their group
members. His care must have been quite extensive, possibly requiring help
beyond simple provision of food and water, and perhaps also including aid
to keep up with the highly mobile lifestyle of his fellows. The combination of
our image of Neanderthals as thuggish with our assumptions about a com-
petitive and individualistic past constrained academic willingness to accept
the evidence from Ned, and from other examples, of apparently extensive
care, however. His extensive care seemed to contrast with every assumption
about our human past as being individualistic and competitive. Davies and
Underdown (2006: 148–49) commented that ‘the extensive intragroup care
needed to sustain such inrm members is surprising unless they provided
some valuable service’. Such evidence, portraying Neanderthals in a very
dierent light from traditional tendencies to see them as some kind of brut-
ish ‘other’ (Madison 2020; Wragg Sykes 2020), has only recently been widely
accepted. As we shall see in this chapter, its implications for our evolutionary
origins have not yet been fully discussed.
Building on Chapter 1, in which we identied important transformations in
human emotional connections, and in compassion and generosity, in the last
few million years of human evolution, here we consider what the material
record might contribute to our understanding of when and how these
changes took place. Further, we consider the implications of these changes for
our understanding of the role of care for the vulnerable in our human origins.
76 HIDDEN DEPTHS
Archaeological evidence for the emergence of human
compassion and generosity
The material record of past behaviour, and the chronology it provides about
changes in human behaviours, emotions and motivations, rarely plays
much of a role in discussions about how our emotional minds evolved. It
is common to simply draw an imagined line between our nearest relatives,
chimpanzees, and ourselves and imagine that the emotional and cognitive
abilities of hominins must have lain somewhere along a path between the
two. This can be misleading, giving a false impression of human evolution
as a progressive advancement rather than a series of pathways and options
(as we discussed in the introduction to the volume), and preventing us from
appreciating some of the similarities in emotional connections that we
share with often distantly related animals.
The archaeological record may provide important insights into the key
changes taking place in compassion, generosity and helping behaviours
in the 7 to 8 million years that separate our common ancestor from our-
selves. The most useful source of evidence is, perhaps, the skeletal evi-
dence of survival from illness and injury, like that demonstrated by Ned
(described above), and what this implies about the changing nature of care
individuals received from others. However, making sense of this record is
not necessarily straightforward and demands critically appraising alter-
native explanations for recovery from illness and injury, developing an
understanding not from any one single case but from the pattern of cases,
and considering the ecological and social context and other evidence for
responses to vulnerability.
Taking these provisos on board, we nonetheless see a more extensive care
for others than we may have imagined. Moreover, this material record is
important, as it gives us an opportunity to better understand changes that
have taken place since our last common ancestor with other apes, and how
these changes relate to distinctively human capacities for aective and cog-
nitive empathy we considered in Chapter 1. At the simplest level, the mate-
rial record suggests a progression through time from the earliest possible
cases of care for the vulnerable, which represent early developments in cog-
nitive and aective empathy, to both a greater frequency of care and a more
complex relationship between intuitive responses, long-term planning and
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 77
cultural traditions. Care for illness and injury may have been both more eco-
nomically and more socially signicant then we tend to imagine.
These developments are reviewed and discussed from the earliest stages
of the earliest beginnings of care to evidence for care around the time of the
emergence of ‘humans’ (early members of the genus Homo) to later periods
of human evolution incorporating archaic and modern humans.
Before two million years ago: earliest beginnings?
Some of the earliest evidence for possible care for illness and injury come
from pre-human contexts over 2 million years ago. Evidence from our
hominin ancestors (members of ‘tribe’ Hominini, or extinct and modern spe-
cies of humans and pre-human ancestors) suggests that, even as early as 3
to 4 million years ago, australopithecines were already becoming notably
social in their orientation compared to their nearest relatives. Canine size,
often an indication of the extent of male aggression, is much reduced in
Ardipithecus, for example (Hare 2017). There is also some evidence, albeit
contentious, that sexual dimorphism, another measure of male aggression,
had also reduced (Plavcan 2012; Plavcan et al. 2005). An increasing need
to collaborate to defend against predators may have been a key selection
pressure, making it more advantageous to help others than to hinder them
(discussed in Chapter 1).
The earliest potential example of helping behaviour for injured or diseased
individuals comes from skeletal remains of two australopithecines found in
South Africa. The rst case is that of a probable Australopithecus africanus
from Sterkfontein in South Africa (Stw 363), dated to around 2 to 2.5 mil-
lion years ago (Pickering and Kramers 2010). Remains of the foot bones of
this hominin show damage to the foot (compression fracture of the calca-
neus, with the talus driven into the upper surface of the calcaneus), which
is likely to have led to severely impaired mobility for at least six weeks after
the break (Fisk and Macho 1992). The second case, an Australopithecus sed-
iba boy (around 12 to 13 years old) from Malapa (MH1), dating to around
2 million years ago, showed evidence of a bony tumour of the spine
(a primary osteogenic tumour, which aected the right lamina of the sixth
thoracic vertebra). This tumour is likely to have limited movement of the
shoulder and upper right part of the back, as well as causing chronic pain
78 HIDDEN DEPTHS
and muscle spasm (Randolph-Quinney et al. 2016). Given the continued
arboreal component of mobility in Australopithecus sediba, this is likely to
have limited mobility. Both cases may suggest some element of at least food
provision given continued survival with the conditions. Figure 2.2 shows a
reconstruction of this hominin.
These earliest cases of potential evidence for helping the ill or injured indi-
viduals suggest a notable survival despite injury that would aect mobility
for at least several weeks if not months. Clearly, severe injuries and illnesses
that aect mobility make it dicult not only to move to nd food but also to
nd water, and to defend oneself or escape from predators.
There are, however, debates over how to interpret such nds. The extent to
which survival despite injury or impairment can condently be interpreted
as implying help from others rests on the implications of impairments for
assistance from others or, conversely, whether these individuals could have
survived independently (for a detailed discussion, see Tilley 2015b). In many
ways, in making inferences about the likelihood that any individual would
have been cared for, we are dealing with a balance of probabilities with
Figure 2.2: Australopithecus sediba. Reconstruction of Australopithecus sed-
iba. Copyright Neanderthal Museum, Holger Neumann.
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 79
dierent factors to take into account. The injuries themselves are implied
from skeletal material, with a certain degree of uncertainty, and their impli-
cations for impairment can vary according to the individual, and within a
context in which our understanding of the physiology and anatomy of past
hominins is far less developed than it is for modern humans. Their interpre-
tation demands a fuller consideration than it might get if we were dealing
with modern peoples.
Doubts about implications?
An important part of the debate over how to interpret the signicance of
injuries in past hominins in terms of helping from others has been analo-
gies with injuries in other primates. In cases of limb and spine injuries, such
as those of the australopithecines described above, it has been argued that
even serious injury may not necessarily imply care, since there are cases
of modern primates who appear to have been able to survive severe inju-
ries unaided (Dettwyler 1991). If the australopithecines were able to survive
unaided, despite injuries that we would usually expect to demand care, then
the potential evidence for helping behaviour would be cast into doubt.
Certainly, modern primate populations can often include individuals with
limb impairments still managing to forage independently (Munn 2006).
Turner et al. (2012) noted, for example, that female Japanese macaques with
limb deformities at Awajishima Monkey Centre, Japan, were equally able to
climb trees or groom others through compensating with posture or use of
other limbs. Individual accounts, such as that of a one-armed gibbon still able
to brachiate (swing between the trees) eectively (Sayer, Whitham, and Mar-
gulis 2007), also point to remarkable abilities to adapt to limb impairments.
The existence of primates surviving limb injuries may appear to suggest
remarkable individual resilience without care. However, there are several
reasons why such studies of non-human primates may not be relevant anal-
ogies for the impact of past hominin injury on survival.
Perhaps the rst, and most obvious, is that non-human primates have a far
greater resilience to limb (and back) injury than do our own bipedal ances-
tors, as their hands and feet can be co-opted to support mobility or manip-
ulation, depending on which limb is damaged. The one-armed gibbon
80 HIDDEN DEPTHS
(above), who was able to brachiate eectively, did so by using their lower
limb ‘instead of’ one arm. There are cases of chimpanzee populations, for
example, where up to 20% of individuals have survived a serious injury and
manage to cope with injured limbs (Munn 2006). However, these are unu-
sual extremes. Moreover, their use of a hind limb to compensate for loss of
use of a forelimb, or vice versa, plays a key role in their adaptations, a luxury
not available to bipedal hominins.
The types and rates of injury in modern primates are not a good analogy for
early hominins either. Particularly high rates of injury typically relate to unu-
sually high rates of intra group violence in common chimpanzees, which
are unknown in other primates, as well as being much higher than in mod-
ern hunter-gatherers (Wrangham, Wilson, and Muller 2006). Thirteen of 20
individuals from chimpanzee populations at Kanyawara and Ngogo showed
healed trauma, for example. However, this is largely due to bites from intraspe-
cic aggression (Carter et al. 2008). Anthropogenically induced injuries
through traps and snares are also common in non-human primates (Stokes
and Byrne 2006), as well as those caused by introduced diseases. In wild pri-
mates in general, injury rates of around 1% are more typical (Turner et al. 2012).
A further confounding factor is that many primate comparisons come from
zoos or provisioned wild populations. Turner, for example, documented
notable survival despite disability in a provisioned population of macaques
(Turner et al. 2014). However, whilst these individuals may cope despite dis-
abilities, impairments in populations who are not provisioned by humans
are known to have a notable eect on their risk of mortality. Disabilities that
slow foraging can reduce food intake at times of resource stress and aect
time available for social grooming (Turner et al. 2014). Deformations aect-
ing symmetry can alter the pace of injured animals. Furthermore, general
deformations potentially increase mortality risk from climbing (Turner et al.
2012), added to which, predators will actively target injured individuals who
are less able to escape.
Trinkaus and Villotte (2017) concluded that comparisons with the level of
independence, despite injury of primates such as those in zoos and those
who are provisioned by humans, underestimates the impact of injury
and impairment on survival unaided in the wild. An image from modern
primates of common, severe injury being survived without care in early
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 81
hominis is not supportable. Focusing on adaptations to impairments in oth-
erwise healthy individuals also overlooks the issue that perhaps the most
signicant eect of injury is in the risk of mortality during a period of inca-
pacitation, rather than how individuals cope after healing has taken place.
For hominins, being incapacitated for a notable period, under a threat of
predation and unable to nd food and water, would have been likely to be
life-threatening without help. Even severe restrictions on mobility are likely
to have brought considerable risk of mortality in a context of high predation
and limited adaptability of forelimbs to improve mobility.
The nature of helping in australopithecines
Given the injuries, it is probable that some level of helping, at least with food
resources and potentially protection from predation, seems likely in the
case of Stw 363, who would have had diculty walking for at least six weeks,
and quite possibly also in the case of MH1.
There are a number of reasons why it may have begun to make sense for
australopithecines to be motivated to help each other. Though there were
various dierent species of australopithecines, they all were small (around
1.2 to 1.5 m high) and bipedal, making them rather defenceless, living in
a more open habitat than their ancestral forest-dwelling relatives. Though
bipedal, they still retained a capacity to hang from trees (as shown by their
curved ngers). The earliest stone tools, dating to around 3.3 million years
ago (Harmand et al. 2015), as well as cut-marked bones from a similar time
period (McPherron et al. 2010), show that australopithecines probably used
such tools to scavenge meat, sinews or marrow from animal carcasses.
Exploiting carcasses would have put them in confrontation with dangerous
predators, placing selective pressures on means to defend themselves as a
group, and thus on collaboration, communication and prosociality (Bicker-
ton and Szathmáry 2011).
The cognitive complexity of helping implied by either of the australopithe-
cine cases need not necessarily have exceeded the complexity seen in other
apes, however. Neither of the australopithecines was fully incapacitated and
they were thus likely to be capable of reaching a water source unaided (even
if more slowly). Most signicantly, they were capable of requesting food.
Food begged from others, or provisioning by kin, could have been enough
82 HIDDEN DEPTHS
to keep these hominins alive for some time. Nonetheless, willingness to
undertake more costly helping behaviour than we have seen in non-human
primates by around 2 million years ago may nonetheless be an indication
of changes in aective empathy to include adult group members, and have
been important in how empathy and social relationships developed in later
hominins; see Figure 2.3.
After two million years ago: the emergence of ‘humans’
Ecological contexts may have been playing a role in increasing inter-
dependence and, with it, probable selection pressures on aective
empathy (described in Chapter 1), around the time when the earliest
‘humans’ emerged.
As environments became increasingly variable and heterogenous, between
about 3 million and 1.8 million years ago (Potts 2012; Potts 2013; Potts
and Faith 2015), an opening up of new opportunities, as well as new con-
straints, seems to have led to a proliferation of dierent hominin forms.
These included the earliest members of the genus Homo or ‘human’ spe-
cies, with at least three species contemporaneous around 2 to 1.5 million
years ago (Antón, Potts, and Aiello 2014), as well as other contemporary
non-Homo species. It is dicult to know how the adaptations of any of
these dierent species dier from each other. Nonetheless, many argue
that a selection for exibility and adaptability in response to highly variable
environments seems to have been a signicant factor in the emergence of a
distinct early human cooperative adaptation (Antón, Potts, and Aiello 2014;
Figure 2.3: Possible implications of the material evidence for care for levels
of cognitive and aective empathy shown in australopithecines. Penny
Spikins, CC BY-NC 4.0.
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 83
Domínguez-Rodrigo et al. 2014; Grove 2011). Environmental variability,
resulting in year-to-year, monthly or even shorter-term changes in the types
and quantities of resources available, places a particular challenge on sur-
vival. As shortfalls in resources become more frequent, increasing any indi-
vidual’s risk of mortality or of failing to reproduce, it makes more and more
sense to share resources according to needs (Barkai et al. 2017; Domínguez-
Rodrigo et al. 2014; Smith et al. 2012). Seen as one of the most signicant
periods of transformation in human evolution, biological changes include
marked brain expansion, slower maturation and changes in body form that
have been interpreted as a response to changes in ecological niche involv-
ing a greater dependence on meat eating (Balter et al. 2012; Foley 2016;
Roach et al. 2018; Schroeder et al. 2014).
The precise changes and pressures at these key points of transition in human
evolution remain debated. Whether ecological changes were the key prime
mover encouraging hominins to move into an increasingly meat-eating
niche, or whether increasing reliance on hunting was in any case a pro-
gressive change already taking place within the Pan/hominin lineage, or
whether it was a rather unique combination of pressures towards interde-
pendence from predation alongside an existing ape social intelligence that
led to new types of hominin collaboration, remains unclear. However, there
is general agreement that hunting, risk-taking and sharing food underlies
this transformation in early members of the genus Homo. Changes in emo-
tional relationships, rather than simply cognitive capacities to plan or come
to agreements, seem to lie at the heart of these transformations (Hrdy and
Burkart 2020; Spikins 2015).
Although attention tends to focus on what are seen as our ancestors, within
the earliest members of the genus Homo there were other alternative tra-
jectories or other journeys along which alternative ancestors may have trav-
elled. Alternative forms were also around during this period. The robust aus-
tralopithecines seem, particularly, to have responded to ecological changes
by specialising increasingly on the exploitation of plant food, in potentially
less risky and more wooded environments (Cerling et al. 2011; Towle, Irish,
and De Groote 2017). Their rough diets led robust australopithecines to
develop a bony crest to support jaw muscle, huge strongly built jaws and
large teeth to process tough vegetation. We can certainly imagine that
relying for subsistence on plant materials is likely to have been much less
84 HIDDEN DEPTHS
demanding of social or emotional understanding than relying on meat (the
exploitation of which would require working together whether confronting
predators or hunting). The buttressing of robust australopithecine faces has
even been suggested to be an adaptation to violent confrontations using
sts (Carrier and Morgan 2015), though other explanations more rooted in
supporting large jaws suggests that this maybe goes a little too far.
As far as early members of the genus Homo, or true ‘humans’, are concerned
there is clear material evidence for greater interdependence. The earliest
evidence for stone tool use comes from around 3.3 million years ago (Har-
mand et al. 2015), when stone tools seem to have been used for scaveng-
ing meat from bones left by higher-level predators. However, stone tool
marks on large animal bones are found from around 2.6 million years ago
(Domínguez-Rodrigo et al. 2005) and provide clearer evidence of being used
in early access to carcasses. The butchering of small antelopes at Kanjera
South in Kenya, around 2 million years ago, has been interpreted as evi-
dence of active hunting (Plummer and Bishop 2016). This hunting of animals
larger than the hominins themselves has been seen as good evidence for
collaborative hunting and, in turn, the sharing of hunted meat (Domínguez-
Rodrigo et al. 2014). By 1.3 million years ago, faunal assemblages at BK at
Olduvai suggest active hunting of not only small and medium-sized prey
but also large ungulates (Domínguez-Rodrigo et al. 2014). Early humans
even hunted extremely dangerous giant gelada baboons at Olorgesailie by
around half a million years ago (Isaac and Isaac 1977; Shipman et al. 1981).
Thus, regular consumption of meat from large mammals has particularly
been associated with the emergence of Homo (Balter et al. 2012; Pante
et al. 2018). Physiological adaptations to increased meat eating were appar-
ent from at least 1.5 million years ago, at least on the basis of the appear-
ance of hyperostosis, indicating anaemia through lack of iron, in a child
1.5 million years old (Domínguez-Rodrigo et al. 2012). Longer periods of
infant dependency point to increasingly collaborative childcare alongside
other major changes such as brain expansion (Burkart et al. 2014; Hrdy and
Burkart 2020).
Evidence for care of the ill and injured
Within this broader picture of sharing, not only of meat but of risks in hunt-
ing and time and eort in childcare, we also see emerging evidence for care
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 85
for the ill and injured. The earliest potential evidence for extended care in
early Homo occurs at around 1.8 million years ago. This evidence comes
from the survival of a near toothless hominin from Dmanisi in Georgia
(D3444/D3900) (Lordkipanidze et al. 2005). The individual had lost all but
one tooth (the left canine) several years before death, identiable through
bone resorption. Soft animal foods, such as brain, may have been easier
for this individual to eat, and it is thus plausible that others provisioned or
even processed (chewed) their food for them. The excavators interpreted
this specimen as evidence of care for those who were ill (Lordkipanidze
et al. 2005). DeGusta (2002; 2003), however, argued that toothless homi-
nins could have survived by nding their own foods, drawing on evidence
for survival in similar cases seen in primates. Certainly, primates with quite
severe tooth loss have been recorded surviving, such as a surviving tooth-
less bonobo (Surbeck 2020) or a healthy baboon from Kibale National Park
who was missing the premaxilla and most of the maxilla and nasal bones
(Struhsaker et al. 2011). This individual, however, possessed third molars,
which will have at least made cutting and chewing of food possible. No sur-
viving primate is recorded with the extent of tooth loss seen in the Dmanisi
specimen, nor for this lengthy a period (Thorpe 2016). Trinkaus and Villotte
(2017) noted that, in several cases, including the Dmanisi individual, tooth
loss is accompanied by severe inammation and periodontal disease. Whilst
managing to nd sucient soft food without help for several years despite
being unable to chew may have been possible, on the basis of analogies with
living primates, surviving a period of this type of systemic illness is a more
reliable indicator of care from others. Individuals in this state will have felt
extremely ill and would have been in pain. Toothlessness remains a dicult
issue to interpret in terms of care (Gilmore and Weaver 2016); however, the
Dmanisi evidence, with systemic infection, can be cautiously interpreted as
likely evidence of care from others.
Two particularly convincing examples of care that clearly go beyond that
recorded in non-human primates also emerge after 1.8 million years ago,
however. Both are from East Africa – an adult female Homo ergaster (1808)
from Koobi Fora, and a young male Homo ergaster/Homo erectus (WT1500)
from Nariokotome.
The Homo ergaster female from Koobi Fora (Lake Turkana, Kenya) is by far the
most famous. Dating to around 1.6 million years ago, this partial skeleton of
86 HIDDEN DEPTHS
a probable Homo ergaster was recovered in 1974. The most notable feature
of her skeletal remains is a build-up (as much as 7mm in places) of coarse
woven bone in the limb bones, with sub-spheral lacunae within this bone
accumulation (Walker, Zimmerman, and Leakey 1982: 248). The cause of this
pathology has been debated. The eect on the bones is, however, typical
of hypervitaminosis. One possibility is that of an excessive consumption of
carnivore livers (something experienced by Arctic explorers who resorted
to eating their sled dogs) (Walker, Zimmerman, and Leakey 1982), another
being an overconsumption of bee brood larvae (Skinner 1991). Hypervit-
aminosis would have caused this individual to have suered from health
implications including peeling skin, vomiting, diarrhoea, headache, con-
vulsion, oedema, inammation of the optic nerve, muscular stiness, itchy
rash, and inammation of the nail beds, as well as periods of unconsciousness
and severe pain for several weeks or, perhaps more likely, even months
before her death (Skinner 1991; Walker, Zimmerman, and Leakey 1982). She
will have been extremely vulnerable throughout this time.
What is clear is that 1808 was unable to nd food for herself or defend her-
self from predators for a substantial period and, for at least some of the time
while she was ill, was unlikely to have been able to give clear cues as to her
needs. She would, however, have needed providing with food and water
and to be protected from predation (Walker, Zimmerman, and Leakey 1982).
In cognitive terms, her care is likely to have demanded instrumental help-
ing (of providing a safe place to rest), proactive sharing (of food), as well as
responses to unsolicited cues (such as for food and water despite any severe
pain, lack of consciousness etc.). Help in this case would have been not
only unsolicited but also extensive and costly, suggesting both more exten-
sive aective empathy (emotional response) and more complex cognitive
empathy (higher-level functioning) to infer what help would be needed to
keep this individual alive than is seen in any non-human primate.
Care for a young male Homo erectus/Homo ergaster (WT 15000 or ‘Nar-
iokotome Boy’), dated to 1.6 million years ago from Nariokotome, would
also have necessitated complex cognitive and aective empathy. This indi-
vidual, who was around eight years old at death (Graves et al. 2010), had a
herniated disc and suered extensive remodelling of part of the spine (the
articular processes of L4 and L5) several months before their death (Schiess
et al. 2014). As a result, he would have suered from disabling backache
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 87
and recurrent sciatica, which would have restricted walking, bending and
other daily activities. It is dicult to see how he could have foraged success-
fully or kept up with a mobile group. Hausler et al. argued that this case also
provides evidence for advanced social care and nursing at this time (Haeu-
sler, Schiess, and Boeni 2013: 3). Figure 2.4 shows a reconstruction of this
individual. An example of possible dental treatment in a further Homo erec-
tus individual from Swartkrans in South Africa has also been seen as possible
evidence for care from others (Ripamonti et al. 2020).
Extended provisioning of the ill and injured, and unsolicited help, would
have been an important element in keeping small collaborative groups of
Homo erectus viable in conditions with high injury risk, and may even have
been a key factor making the colonisation of northern temperate zones
possible (Spikins et al. 2019). Control of infectious diseases is unlikely to
have been a key factor in the emergence of healthcare practices, given evi-
dence that early hominins lived in small inward-focused social groups (dis-
cussed in Chapter 4) and the prevalence of injuries and degenerative rather
than infectious diseases in the palaeopathological record. Nonetheless, at
Figure 2.4: Turkana Boy (detail). Reconstruction of Nariokotome (Turkana)
Boy, typical of a Homo erectus/Homo ergaster. Copyright Neanderthal
Museum, Holger Neuman.
88 HIDDEN DEPTHS
a later date, as populations became larger and more connected, care may
also have been important in managing infectious diseases (see Kessler 2020;
Kessler et al. 2017).
Whether this care represents as complex a level of cognitive or aective
empathy as we identied as characteristic of humans today remains a ques-
tion. We can be condent that early members of the genus Homo had some
abilities to provide unsolicited help (such as for the female Homo ergaster,
who will have spent some time unconscious and unable to request help
but yet need protection) and towards long-term goals (such as through
providing water), and helping is costly, though not lifelong. However, there
is as yet little evidence for helping of non-kin or strangers or discriminate
helping (Figure 2.5). Of course, such more emotionally extensive and
cognitive complex care may have existed at this time but not leave any
material evidence.
The signicance of even intuitively motivated care, much like that for vul-
nerable young, is nonetheless clear. We can see how important simple pro-
visioning and protection becomes to survival through considering modern
hunting and gathering societies. For modern hunter-gatherers, even with
the benets of a modern mind, reduced risks of predation seen in early
humans and complex technologies including projectiles, care for illness and
injury is still essential to maintaining survival. Sugiyama (2004) reported
that, amongst the Shiwiar hunter-gatherers, for example, around 50% of
adults had been incapacitated and unable to forage for at least a month,
and would not have survived without provisioning and care from others.
Figure 2.5: Possible implications of the material evidence for care for levels
of cognitive and aective empathy shown in early members of the genus
Homo. Penny Spikins, CC BY-NC 4.0.
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 89
Care as part of increasing interdependence
Social transformations around this time have typically been viewed from
the perspective of biological changes in the body, or as an example of
increased intelligence overall, or social and collaborative intelligence. How-
ever, changes in emotional dispositions may have played a key role in how
humans aected a transformation from being individuals within a loose
group to highly collaborative bands. Individuals who had begun a jour-
ney to being more interdependent could now work like a ‘single predatory
organism’ (Whiten and Erdal 2012).
Increased meat consumption provides direct fuel for brain expansion, but
changes in emotional dispositions leading to cooperative breeding may
also be critical to being able to support ever larger brains by reducing the
energetic costs to mothers of raising large-brained infants (Hrdy 2011). This
involvement of fathers and others in childcare may have been key to allow-
ing humans to break through a ‘grey ceiling’ of limits to social and cognitive
intelligence that aect other species (Isler and van Schaik 2012).
Through sharing risk, foodstus and care via tendencies to mutual generos-
ity, humans will have reduced the risks of individual failure as well as being
able to hunt larger game (see Figure 2.6). Moreover, modern foragers both
hunt and gather, with the former giving higher returns but the latter being
more reliable. Starchy foods, such as tubers, may have played an important
complementary role, perhaps as fallback foods (Hardy et al. 2015; Marlowe
and Berbesque 2009). A social carnivore-like level of collaboration also pro-
vides potential means of adapting to risk in other ways. Hyenas, for example,
hunt food and collaborate to defend their group with non-relatives (Schaller
and Lowther 1969; Smith et al. 2012), and group sizes can alter according to
the season or ecological context. If early humans also lived in exible groups,
this could have been important to adapting to seasonal or longer-term
ecological changes. This exibility of community may have been particularly
important as a means by which human communities adapted to ecological
changes (Grove, Pearce, and Dunbar 2012).
The care for illness and injury described above is most probably the most
archaeologically visible element of extensive emotional motivations to help
90 HIDDEN DEPTHS
others within one’s group (Hrdy and Burkart 2020; Spikins 2015). However,
interdependence and increasingly strong emotional connections, sup-
ported by changes in particular brain regions as well as bonding hormones
(discussed in Part 2), will have aected many dierent behaviours (includ-
ing the sharing of food, shared care of ospring and collaborative defence
and resource gathering; Feldman 2017), much like changes in the helping,
sharing and aection that also developed in increasingly interdependent
social carnivores.
Support for the primacy of emotional and social changes before other areas
of cognition comes from one particularly notable alternative human adap-
tation. Studies of crania of Homo naledi, from the Rising Star Cave system in
South Africa (Berger et al. 2015), demonstrate that this species had a com-
plex forebrain, in common with other members of the genus Homo. Endo-
casts showed frontal parts of the brain associated with processing emotions
and understanding social relationships such as the pars orbitalis, which
involves Brodmann’s area 47, associated with the recognition and produc-
tion of social emotions, social inhibition, and emotional learning (Holloway
Figure 2.6: Selection pressures on aective and cognitive empathy driven
by increased meat eating. Penny Spikins, CC BY-NC 4.0.
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 91
et al. 2018: 5741). However, Homo naledi had a very small overall brain size,
similar to that of the australopithecines. Their emotion processing capaci-
ties seem to be ancestral to Homo and may explain behaviours such as the
deliberate deposition of their dead in the Di Naledi chamber. Emotion pro-
cessing, rather than brain size, seems to be key, not only to complex social
practices such as these but also to some degree of adaptive success, with
Homo naledi surviving alongside other large-brained hominins until at least
300,000 years ago. The late existence of this small-brained but socially and
emotionally complex human is interesting, not only in demonstrating dif-
ferent evolutionary pathways and dierent ways of being human but also
when we consider what it may mean about possible constraints. Whilst
Homo naledi remained successful despite larger-brained contemporaries,
there are, as yet, no known hominins making a living with a large brain
but underdeveloped social and emotional processing areas. This may add
additional support to the signicance of emotional connections, rather than
analytical processing capacities, to what made us human. Care for illness
and injury may have had other consequences, aside from forming the basis
for complex areas of cognition, particularly in its inuence on human cul-
tural evolution and our dependence on the cultural transmission of ideas.
After half a million years ago: later periods
of human evolution
By around half a million years ago, we see diverse species of humans occu-
pying northern latitudes, including Europe, as well as Africa and Asia. These
species were quite dierent in form. One broad type included humans who
were very robust with prominent brow ridges, such as the northern-latitude
and Asian group including Neanderthals, Denisovans or Homo longi.
Another broad type was of much smaller- and small-brained humans,
such as Homo oresiensis or Homo naledi. A third type of humans, appear-
ing in Africa from 300,000 years ago, were more gracile, with reduced brow
ridges. The latter, gracile type includes the ancestors of our own species. Despite
their dierences, interbreeding occurred between these dierent forms and
all are generically termed archaic or pre-archaic Homo or Middle Pleistocene
Homo, though, as we shall see in Part 2, some dierences between these
types may be signicant in terms of tolerance and emotional sensitivity. It is
in this period that we see the earliest evidence for long-term commitments
from the group as a whole, suggesting a sense of collaborative investment
92 HIDDEN DEPTHS
in care, as well as uncalculated care for even the most severe of injuries
and illnesses.
At Sima de los Huesos in northern Spain, at least three of the around 28
individuals of pre-archaic/Neanderthal populations deposited in a mor-
tuary pit appear to have been supported through particular pathologies
( Carbonell and Mosquera 2006). The best-known of these cases of extended
care, that of an eight-year-old child with craniosynostosis, a torsioning of
the crania, is perhaps not particularly surprising (Gracia et al. 2009). Mater-
nal care for infants, even those who are ill or dierent, is recorded in apes,
such as an infant chimpanzee with Down’s syndrome in Mahale Mountains
National Park, who was carefully looked after by their mother (Matsumoto
et al. 2016). Moreover, craniosynostosis does not always have noticeable
cognitive implications. However, the continued survival for several years of
a dierent individual, an elderly man with a deformed pelvis who would
only have been able to walk with the aid of a stick (Bonmatí et al. 2010; Bon-
matí et al. 2011), does point towards support of the vulnerable, regardless
of whether they could contribute in an economic sense. A further hominin
with possible hearing impairment (Trinkaus and Villotte 2017) is at least sug-
gestive of a certain level of accommodation for dierence.
It is, however, in descendants of the Sima de los Huesos populations that
we see the most widespread evidence for extended care (see Figure 2.7).
Neanderthal populations, the occupants of Europe from around 300,000 to
30,000 years ago, who are discussed in more depth in Chapter 8, provide us
with many notable examples of care for the ill and injured.
Life was most certainly challenging for these populations. Famines were
not uncommon and, in the often cold and arid environments in which they
lived, nding food seems to have demanded high levels of mobility, with
resultant stress on their bones. Though it is dicult to interpret injury rates
precisely, given the nature of the archaeological record, it seems from the
skeletal material available to us that illnesses and injuries appear to have
been frequent, with most Neanderthals suering a severe injury of some
kind before they reach adulthood (Berger and Trinkaus 1995; Pettitt 2000).
Healthcare may have been part of the adaptations that allowed occupation
in such dicult conditions, particularly given a heavy reliance on hunted
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 93
meat and small group sizes, all of which will have made the survival of each
person signicant to the whole group (Spikins et al. 2018).
Shanidar 1 was not alone in surviving severe injury and lasting impairment.
An individual from La Chapelle-aux-Saints was also cared for despite a range
of impairments and, perhaps most importantly, with no real hope of recov-
ery (Bouyssonie, Bouyssonie, and Bardon 1908; Dawson and Trinkaus 1997;
Trinkaus 1985), later being carefully buried (Dibble et al. 2015; Rendu et al.
2014; Rendu et al. 2016); see Figure 2.8. Tilley (2015a) described his patholo-
gies in detail, including extensive tooth loss and severe, chronic periodontal
disease; temporomandibular joint arthritis; severe osteoarthritis in lower
cervical and upper thoracic vertebrae, and moderate to severe degenera-
tion of lower thoracic vertebrae; osteoarthritis in both shoulder joints; a
rib fracture in the mid-thoracic region; degeneration in the fth proximal
interphalangeal joint of the right foot; and severe degeneration and likely
chronic osteomyelitis in the left hip (Tilley 2015b: 228). Most particularly,
degenerative disease in the spine and shoulders would have aected his
upper body movement, whilst his diseased left hip would have imposed
Figure 2.7: Homo sapiens neanderthalensis. Reconstruction of a Neander-
thal. Copyright Neanderthal Museum, Holger Neumann.
94 HIDDEN DEPTHS
signicant pain and restricted the use of his left leg to bear weight. Underly-
ing infection, both localised and systemic, would also have taken a progres-
sive toll on his health and strength over the last year of his life. We can only
imagine how ill and vulnerable he must have felt.
Both La Chapelle-aux-Saints 1 and Shanidar 1 would have been unlikely to
have survived lengthy and severe impairments without involvement from
the whole group in their care. Moreover, given that improvements would
evidently have been unlikely, such care must have been uncalculated. Even
provisioning a single individual who was immobile, or with severely impaired
mobility, for a short time would have been dicult. However, the extended
provisioning and care in place (which in the case of La Chapelle-aux-Saints
1 can best be described as nursing) would also have demanded a sharing
of responsibility. That care was uncalculated, irrespective of whether these
individuals would recover or ever return the investment in them, is evident,
changing many of our preconceptions of Neanderthals.
Figure 2.8: The La Chapelle-aux-Saints Neanderthal burial. Musée de La
Chapelle-aux-Saints, Corrèze, France. 120/V. Mourre, CC BY-SA 3.0, via
Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Recon
stitution_sepulture_Chapelle-aux-Saints.jpg.
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 95
Other cases of serious injury, such as fractures of weight bearing bones, are
also likely to imply a period of provisioning. La Ferrassie 1 (Tilley 2015a) and
Tabun 1 (Abbott, Trinkaus, and Burr 1996) have recovered from severe breaks
to their main leg bones, for example, and Shanidar 3 a break or sprain of the
right foot leading to marked osteoarthritis (Trinkaus 1983). La Ferrassie 2,
a young female adult buried in close proximity to La Ferrassie 1, displayed
evidence of a proximal fracture of the right bula that is completely healed,
although with signicant distortion (Heim 1976). Wynn and Coolidge (2011)
argued that those with lower leg injuries ought to have been too much of a
burden to sustain and may have been abandoned, and Berger and Trinkaus
(1995: 138) commented that ‘abandonment of older individuals who could
no longer move with the social group is likely to have been common.
This would have occurred especially in cases of severe lower limb injury’.
The healed injuries in these individuals point in contrast, however, to care
despite immobility. It is possible that human populations routinely adapted
their mobility patterns around the need to leave the vulnerable or young
to be cared for in particular locations. It has been argued that Wonderwerk
cave in South Africa could be one such location. This cave was apparently
used extensively for shelter, with evidence for the use of re without any
intensive use of stone tools (Chazan 2021).
Might immobile individuals, or those with restricted mobility, have been
able to contribute to tasks suitable to their abilities? This would have
been unlikely in cases of severe pain or systemic infection. However, in
other cases we might expect some activities to be possible. We do not
know whether Neanderthals felt only certain people could perform particu-
lar tasks. Some authors have argued for a lack of gender-based division of
labour in Neanderthals (Balme and Bowdler 2006; Kuhn et al. 2006). However,
recent evidence from dental microwear suggests that at three sites, l’Hortus
(France), Spy (Belgium), and El Sidrón (Spain), females were chewing dier-
ent materials, perhaps indicating preparation of hides (Estalrrich and Rosas
2015). Even so, cold, arid and high-latitude environments demand substan-
tial time investments in making all the kinds of things that are needed to
survive (Bleed 1986), and, whether this is the manufacture of clothing or
tools, there will have been sedentary occupations providing possibilities for
those with limited mobility to contribute. Moreover, groups of Neanderthals
will have included within them children, many of them vulnerable and with
reduced mobility themselves due to their age. Neanderthal children did not
96 HIDDEN DEPTHS
reach adulthood until approximately similar ages to modern hunter-gath-
erers (Ponce de León et al. 2016), and at least half of any group was likely to
consist of children (Shea 2006). As well as sedentary contributions by mak-
ing things (such as clothing or tools), opportunities to contribute to child-
care are likely to have existed for those who could not travel far. Further, the
lengthy period of dependency of Neanderthal children carried other impli-
cations for care provision. Rather than any radical change to mobility or pro-
visioning, healthcare for those with reduced mobility may have tapped into
existing adaptations to care for vulnerable young.
Even where individuals remained mobile, many conditions may have required
some care or accommodation. Individuals with breaks to major bones in the
arms will also have needed at the very least an accommodation of suitable
tasks, for example. The serious arm injuries of Neanderthal 1 (Feldhofer)
(Schultz 2006), Krapina 180 (Eddie 2013) and La Quina 5 are likely to have
aected their ability to forage independently, for example. As discussed,
unlike other primates, humans cannot use either arm or leg as alternative
limbs (for weight bearing or manipulation). Other injuries such as the pro-
jectile point injury to the ninth rib of Shanidar 3, speculated to be a result
of interaction with modern humans (Churchill et al. 2009), will also have
aected health and mobility. Furthermore, head injuries can also require care
depending on severity. St Cesaire 1 (Zollikofer et al. 2002) and Krapina 37
(Russell 1987) suered severe head wounds that had afterwards healed, in
the case of the St Cesaire Neanderthal over a period of several weeks.
Toothlessness, as previously discussed, remains a rather more dicult case.
Primates with quite severe tooth loss can survive unaided for some time.
Nonetheless, Trinkaus argues that it is likely to have had more signicant
impact, with severe inammation, as seen in Aubesier 11 and Guattari 1
(Trinkaus and Villotte 2017). Other conditions also had a lifelong eect, like
that of an archaic human woman from Salé in Morocco with congenital tor-
ticollis who reached adulthood, despite the condition, which is associated
with reduction mobility of the neck as well as other debilitating symptoms
(Hublin 2009).
The level of care given to those in need, even where there will evidently be
no direct ‘pay o’ (as is the case with Shanidar 1 and La Chapelle 1) argues
that care was in no way calculated but a genuine immediate response to
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 97
vulnerability. These were likely to be societies with strong bonds based on
empathy and high levels of trust, promoting the kind of social and emo-
tional environments that foster a willingness to take risks and costs on oth-
ers’ behalves.
Care amongst Neanderthals also implies a sophisticated level of
knowledge and planning. High rates of healing and low rates of infection
(Trinkaus and Zimmerman 1982: 75) argue for planned care practices for
the injured. Bitter-tasting plants with no nutritional value found in dental
calculus provide evidence for possible medical consumption, for example
(Hardy 2018; Hardy 2019; Hardy et al. 2012). Poplar in the dental calculus
of a Neanderthal with a dental abscess from El Sidrón may have been used
as a painkiller as it contains salicylic acid (which acts as a painkiller in aspi-
rin) (Weyrich et al. 2017). Ochre may also have been used as an antiseptic
(Velo 1984) and tar may also have been chewed for the same reason, as well
as in maintaining the teeth (Aveling and Heron 1999). Toothpicks were also
used, in the case of an individual from Cova Foradà in Spain to apparently
attempt to treat periodontal disease (Lozano et al. 2013). Medicinal knowl-
edge is likely to have been handed down over generations and culturally
variable in dierent regions. Whilst particular practices of care tend to be
culturally specic, a knowledgeable, organised and caring response is typi-
cal from archaic humans onwards. Though there is no direct evidence, we
reasonably assume that birth assistance was widely practised – Neanderthal
babies were born with a modern human pattern of head rotation at birth
(Ponce de León et al. 2008), demanding assistance, and birth assistance has
even been recorded in bonobos (Demuru, Ferrari, and Palagi 2018).
As we shall see in Part 2 of this volume, there are important dierences
between societies of archaic humans and the descendants of these
populations who left Africa after 100,000 years ago – modern humans, ana-
tomically and cognitively identical to ourselves. Care for the ill and injured,
however, shows only subtle dierences.
There continue to be examples of uncalculating care for those in need,
regardless of any possible direct ‘pay o’, as well as care that must have been
shared between many individuals. The Ohalo 2 individual, from the Upper
Palaeolithic of south-west Asia dated to 23,000bp, for example suered a
thoracic injury causing ossication of the sternum and adjacent cartilage. He
98 HIDDEN DEPTHS
would have struggled to have breathed actively, making anything more than
very short bursts of activity impossible. Care from the rest of his group would
have been likely to have been needed to support him (Trinkaus 2018a). Like
other key Upper Palaeolithic examples in Europe, such as Barma Grande 2,
Brno 2, Cro-Magnon 1, Dolní Věstonice 15, Rochereil 3, Romito 2, and Sung-
hir 2 and 3 (Trinkaus 2018a), his level of survival despite injury or impairment
provides good evidence for empathetically motivated care from the small
hunting and gathering groups of which these individuals were a part.
Where we see subtle dierences is around a certain unusual attention to
disability and impairment. Individuals with impairments were apparently
selected for particular burial in Upper Palaeolithic Europe (around 30,000
to 10,000 years ago), for example (Formicola 2007). Examples include the
Romito child, with dwarsm, buried under a depiction of an aurochs (Mal-
legni and Fabbri 1995), two juveniles at Sunghir in Russia, one with severely
bowed legs and another with severe facial abnormality (prognathism),
interred with elaborate burial goods, including 16 mammoth ivory spears
(Trinkaus and Buzhilova 2018), the central individual of an elaborate triple
burial at Dolní Věstonice who had severe limb abnormalities (Trinkaus et al.
2001) and a woman from the same site with a facial deformation (buried
under the scapula of a mammoth, and covered with red ochre). In the latter
case, a gurine with the same facial deformation as the woman was also
found from the same site, suggesting that her facial dierence made her in
some way special.
We can see various types of accommodations for illness or injury in mod-
ern hunting and gathering populations. Amongst the modern-day Baka,
individuals with severe mobility impairments take on important social roles
(Toda 2011). Whilst the dierentiation of individuals with disabilities remains
enigmatic, it best represents in general terms the signicance of reputation,
with the determination of disabled individuals to overcome adversity gain-
ing them a certain respect.
To some extent, some forms of social dierentiation may be apparent in
archaic populations, even if less visibly so. We may see a dierent treatment
of dierent people in Neanderthal populations in mortuary practices, where
older males with injuries may be more likely to be buried after death, and
in distinctive practices around children, such as the burial of a child with
possible grave goods at Dederiyeh in Syria (see Spikins et al. 2014).
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 99
It is clear that archaic and later humans were capable of complex planning
around care, and had the emotional capacities which prompt us to costly and
lifelong acts of care for those we love (see Figure 2.9). A dierent treatment of
dierent people provides us with evidence of discriminate helping, one
of the more complex features of cognitive empathy identied in Chapter 1.
The question of an extended aective empathy, prompting an extension of
helping to non-kin and strangers familiar to modern societies is, however,
almost impossible to identify from survival from illness and injury and is a
topic we turn to in Part 2.
It is not dicult to identify a broad pattern of changing responses to vulner-
able, ill and injured individuals, from possible early examples, perhaps not
dissimilar to those practices seen in other mammals and particular social
carnivores, to more widespread, long-term and knowledgeable care later in
human evolution. Interpretations of care, and of what behaviours mean
in terms of the emotional motivations underlying such care, particularly if
we try to focus on individual cases, are not without their issues, however.
There have been a number of issues raised with interpretations of care that
warrant discussion.
To what extent can archaeological evidence be used to infer
key changes in emotional connections and capacities
for compassion?
There are several key challenges to address in making inferences from
skeletal records of recovery from illness and injury. Firstly, there are many
biases aecting the archaeological record that may inuence our interpre-
tation. Secondly, there are a number of unknowns. Most particularly, it can
be dicult to infer the extent to which any individual may have been able
Figure 2.9: Possible implications of the material evidence for care for capac-
ities in cognitive and aective empathy in archaic and modern humans.
Penny Spikins, CC BY-NC 4.0.
100 HIDDEN DEPTHS
to survive alone or tolerate particular conditions, particularly when we are
dealing with hominins who were anatomically and perhaps even physio-
logically dierent from ourselves. Lastly, evidence for helping, particularly
in the complex societies of cognitively modern humans, is not always evi-
dence of compassionate motivations – helping can be motivated by calcu-
lated intentions rather than genuine empathy or compassion.
The issue of bias is a pervasive one when dealing with archaeological evi-
dence. Only certain types of materials are preserved, under particular condi-
tions and in particular places. Human and animal bones can sometimes be
preserved where the conditions are suitable for their preservation. Some
of our best-preserved skeletal records come from particular contexts, most
notably burial practices, which may not be a representative sample of the
people at the time (Spikins et al. 2014; Spikins et al. 2018). Moreover, we
can sometimes question the reliability of inferences from a small number
of individuals spread out over large areas of time and space. Neither can
modern biases be discounted: until recently, fragile infant bones were only
rarely recovered on excavations, further biasing the record. Interpretations
can never be entirely straightforward.
Inferring implications in terms of care is also dicult. We usually underes-
timate the prevalence of injuries and illnesses requiring treatment as even
quite severe injuries and illnesses often leave no trace on the human bones.
In fact, well over 90% treatments for illness or injury in wilderness loca-
tions, many of which would have contributed to saving lives, would leave
no indications on skeletal evidence (Spikins et al. 2019); see Figure 2.10. Our
evidence of illness and injury is thus only a tiny window onto the actual inju-
ries, illnesses and impairments that people experienced in the past.
Whilst the restricted visibility of most pathologies requiring care means that
our estimates of care are underestimated, other factors may elevate our
impression of the care that was given to particular individuals. It is often dif-
cult to infer exactly the nature of injury or illness. Few skeletal remains from
the distant past are complete and most are missing many elements, which
makes inferring the implications challenging. Alternative explanations for
the pathologies seen in 1808 include yaws (Treponema pertenue) (Roths-
child, Hershkovitz, and Rothschild 1995) and sickle cell anaemia (Jeerson
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 101
Figure 2.10: Medical treatment in wilderness locations. National Outdoor Leadership school’s incidents requiring medical
attention in wilderness activities in Wyoming, Alaska, Arizona, Washington, Idaho, Mexico, Chile and the Yukon Territory; 1051
individuals (average age 22 years) 1998–2003. Data from McIntosh et al. 2007. Penny Spikins, CC BY-NC 4.0.
102 HIDDEN DEPTHS
2004), for example, though hypervitaminosis best ts the bone pathology
(Dolan 2011). We also have to bear in mind that our modern analogies may
not be as relevant for early hominins as we might hope, and individuals in
the past may have been more independent than we might give them credit
for (Degusta 2002; Dettwyler 1991). Cowgill (Cowgill et al. 2015), for exam-
ple, noted that a young female buried at Sunghir during the Upper Palae-
olithic showed extensive evidence for sustained mobility despite notable
bowing of her legs, demonstrating that she kept up with the group despite
this impairment. Self-care and self-medication may also be a factor. A Homo
erectus from Swartkrans with probable intentional removal of an M3 molar
that is likely to have been infected and shows subsequent bone regrowth
around the side might conceivably have removed this tooth by themselves
rather than needing help from others, for example (Ripamonti et al. 2020).
These issues mean that the less severe cases of pathology are more debat-
able in terms of care from others.
Making inferences about emotional motivations from past behaviours,
themselves inferred from material evidence, is also subject to a number of
challenges.
It is clear that were all born with a capacity for compassion, generosity and
a whole range of helping behaviours (as we have seen in Chapter 1), and
that helping and provisioning of group members is unsurprising given its
appearance in highly independent mammals such as many social carni-
vores, African painted wolves being a particular case.
A broad capacity for compassion is not, however, enough to infer that this
must have been a motivation in the past in any particular instance. A par-
ticular challenge to interpretations of archaeological evidence for helping
in the past is, however, the possibility of particularly human motivations of
deception, adherence to norms, or concerns with status rather than genuine
empathy (Figure 2.11). Other animals do not deceptively help individuals
that they do not care about, nor do they help because of a social or cultural
norm, so we reasonably assume that their helping reects an immediate
emotional response. Modern humans and by implication potentially earlier
species besides are much more complex in their decision-making, however.
At one extreme, a response to distress that is always calculated (rather than
genuine) would be considered a disorder in humans; nonetheless, in large
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 103
human societies where relationships of dierent kinds are formed with many
dierent people, helping others on a day-to-day level can be motivated by
all kinds of complex social factors. These can include motivations such as a
desire to improve social standing, or for recognition, as well as calculated
self-interest (Böckler, Tusche, and Singer 2016). Moreover, tendencies to
compassion can be blocked by stress, depression or anxiety (Gilbert 2005).
In fairness, our experience in modern industrialised societies is not neces-
sarily a good analogy for the past, as small-scale hunting and gathering
societies operate far more intimate social relationships where deception or
a lack of genuine motivations cannot be ‘pulled o’ for long (Boehm 2012).
Even so, even in such highly intimate contexts there will be occasional
deception or self-oriented motivations. Serious selshness or exploitation is
strongly resisted, even to the point of assassination (Boehm 2012). However,
in modern hunter-gatherer contexts, many people can ‘get away with’ a low
level of individualistic motivations or deception at certain times. Peterson
described, for example, how the Australian Pintupi uphold the common
hunter-gatherer ethic of food sharing, yet tolerate a certain level of hiding
food to prevent others from asking for it (Peterson 1993). Likewise, Hadza
men consume more food away from campsites, where they are not seen,
rather than visibly eating something that might be shared (Berbesque et
al. 2016). Equally, whilst people may not always feel like helping others’
infants, sharing food or caring for the ill, unlike other animals we recognise
that social reputation is aected by not seeming generous of time or eort.
Moreover, even in the most collaborative of setting there will still be some
Figure 2.11: Alternative motivations for helping in response to others’
needs or distress. Penny Spikins, CC BY-NC 4.0.
104 HIDDEN DEPTHS
people whose attachment insecurities will inuence how genuinely they
are about others’ wellbeing. The modern Inuit, for example, acknowledge
that orphans tend to be more competitive (and less genuinely motivated by
others’ needs) than those who have experienced a more secure upbringing
(Briggs 1970).
These limitations mean that we can rarely place too much emphasis on any
isolated example of helping behaviour. Broader patterns remain reliable,
nonetheless. Genuine motivations are far more prevalent than calculated
ones, and the most parsimonious (and simplest) explanation is that of an
immediate uncalculated response, meaning it is reasonable to infer genu-
ine compassion when we see widespread evidence for care of the injured
(Flack and de Waal 2000). This does not mean that there are no exceptions.
Capacities to be cunning, deceptive and calculated in response to others’
needs clearly evolved in a constant and complex dynamic alongside those
to convince others of genuine intentions, to detect deception and to pun-
ish cheats (de Quervain et al. 2004); see Chapter 3. These will certainly be
present in cognitively modern humans and quite possibly much earlier.
Sustained care for others, and other prosocial collaborative behaviours such
as widespread food sharing, can only be sustained where the majority of
individuals are genuinely altruistic, based on shared emotional responses
to those in need (Egas and Riedl 2008). Nonetheless, a certain realism about
human nature suggests that some will always be ‘cheating’ and no one is
genuinely compassionate all of the time.
These potential complex variations imply that we should be careful not
to make interpretations based on any single instance of probable care,
though broad patterns occurring over long periods of time, as outlined
above, withstand scrutiny. Moreover, these broad patterns of interdepend-
ence and response to vulnerability are reected in other areas of the archae-
ological record.
Other realms of material evidence for helping those in need
We have focused here on evidence for care for illness and injury. However,
whilst survival from injuries is the most obvious realm of evidence for care
and compassion, it also ts within other realms of evidence.
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 105
In broad terms, evidence for extended helping of those with illnesses
and injuries ts with other lines of evidence for key social changes. These
include evidence for extended childhoods, implying collaborative infant
care, as well as evidence for the hunting and sharing of large game, requir-
ing collaborative eort. These dierent elements of responses to needs and
vulnerabilities imply emotional attunement, sharing and generosity were
emerging as a response to increasing interdependence from at least 2 mil-
lion years ago (Smith et al. 2012; Whiten and Erdal 2012).
There are also more specic lines of evidence indicating closer emotional
relationships and empathetic responses. The most obvious are mortuary
practices. There is potentially some evidence of mortuary ritual as early as
3 million years ago, though evidence becomes more frequent after half a
million years ago (Pettitt 2013). In some cases, it is hard to avoid the sense
of emotional connection in life shown by the care aorded to the deceased.
One example of such is the careful burial of a Neanderthal child at Dederi-
yeh Cave, Syria, with a int ake carefully placed on their heart and stone
above their head, likely as a collective response to a sense of loss (Spikins
et al. 2014). As we have seen in Chapter 2, aective empathy for the living
is often linked to particular grief-like attitudes at death, shown in species as
widely separated as jays (Iglesias, McElreath, and Patricelli 2012), dingoes
(Appleby, Smith, and Jones 2013) and chimpanzees (Biro et al. 2010).
A response to vulnerability is also evident beyond relationships with
other people. Later in the archaeological record we see direct evidence
for something we might see as animal companions, in the form of animals
such as dogs buried with people or as if they were people (Morey 2010)
(discussed in more detail in Chapter 6). However, even around the time of
early Homo groups, animals were more than just an objectied food source.
Handaxes made from elephant bone, found from about 1.4 million years
ago, for example, are less practical than their stone counterparts and sug-
gest that elephants had some particular meaning (Barkai 2021; Zutovski
and Barkai 2015). Humans might even have recognised their empathy and
capacity to care for others. By the time of archaic humans, such as Neander-
thals, several dierent types of artefacts suggest a more complex relation-
ship with animals, including the use of raptor talons and feathers presum-
ably as decoration (Romandini et al. 2014).
106 HIDDEN DEPTHS
It is also particularly notable that the earliest examples of what we term
‘art’ show the characteristic infant-like proportions that prompt empathetic
responses today. The Makapansgat pebble, for example, not created by
humans but carried several kilometres by an australopithecine to the site of
Makapansgat in South Africa, has baby-like face proportions. Similarly, the
Berekhat Ram gurine from Israel, dated to 250,000–700,000bp, has infant
proportions, and the rst construction of a human face, the Roche-Cotard
mask, made by Neanderthals and dated to 33,000bp, also has infant-like
proportions. This form suggests that, whatever their appeal as ‘art’, a response
to vulnerability was also important in the creation and use of these objects
(Spikins et al. 2014). These may be evidence of the sensitivity that is critical
to human attachment and learning. Attachment processes and a drive to
care for objects may even be an unrecognised part of how much handled
items of Upper Palaeolithic portable art may have provided comfort, much
like treasured jewellery today (Bell and Spikins 2018), discussed in Chapter 5.
The eects of a drive to care for things in the world around us can be felt in
far more varied spheres than we might imagine.
Implications: a long evolutionary history of human
vulnerability, compassion and interdependence
There are a number of implications arising from evidence for care for ill-
ness and injury and its association with other changes taking place during
human origins.
Care for adults who are vulnerable, over either the short or the long term,
aects the whole structure of communities (see Figure 2.12). On a biological
level, care for injury and illness changes the parameters over which selec-
tion pressures operate. Assisted childbirth, for example, increases infant
survival and changes pressures on female pelvis size and shape, whilst sup-
port to allow bone breakage can reduce selective pressures on robusticity
(see, for example, Stieglitz et al. 2020). On an economic and ecological level,
recovery from injury allows humans to move into niches with high injury
risks, such as those involving hunting dangerous animals (Spikins et al.
2019). Socially, care for vulnerable adults leads to increasing life expectancy,
generating older individuals able to provide extra care for infants or sup-
port parents, and able to pass on important knowledge and skills (Spikins
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 107
Figure 2.12: Implications of care for adults with vulnerabilities for other human traits. Penny Spikins, CC BY-NC 4.0.
108 HIDDEN DEPTHS
et al. 2019). Older men amongst the Aché of Paraguay, for example, have a
much higher rate of hunting eciency, despite being less physically strong
than their younger counterparts, as hunting requires much skill, learnt over
many years or even decades (Koster et al. 2020; Walker et al. 2002). Being
able to support occasional vulnerabilities also opens up possibilities of sup-
porting individuals with conditions incurring occasional dependencies on
others, including emotional challenges or cognitive dierences (discussed
in Chapter 3). Care also makes trust important to facilitate give and take, and
opens up the possibility of developing communities with a sense of social
safety (also discussed in Chapter 3).
Care for vulnerable adults also changes how we view our evolutionary
past and suggests that we need to reappraise our narrative of human
independence to one of interdependence, vulnerability and response. A
fundamental interdependence, of which care for others’ health and a reli-
ance on others for our own is only part, seems to have been part of our
evolutionary history from as far back as 2 million years ago. Much as we
might like to portray an image of ourselves as physically invulnerable and
independent, the average human from at least 2 million years ago onwards
is likely to have suered a range of illnesses and injuries, many of which
required help from others. Almost all skeletal remains demonstrate a range
of such pathologies (Trinkaus 2018b). Moreover, shared resilience comes
with compromises in terms of individual emotional vulnerability – suscep-
tibility to others distress and a desire to help, and a certain other-focused
emotional sensitivity.
We can see these interdependencies and vulnerabilities today. A funda-
mental dependence on others for survival is evident in modern hunt-
ing and gathering societies. For these societies, survival itself depends on
willing care from others at times of need. Amongst the Aché of Paraguay,
adult males are typically provisioned or cared for by others for 21% of
potential hunting days when unable to hunt due to injury or illness (Gurven
et al. 2000; Hill and Hurtado 2009), for example, and similar rates have been
recorded amongst the Efe of the Ituri forest (Bailey 1991). Seventy-ve per
cent of adults amongst the Tsimane were unable to get out of bed at least
once in a three-month period, for example due to being incapacitated by
illness or injury (Hill and Hurtado 2009), and this period of illness lasted
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 109
more than three days in over 90% of cases (Gurven et al. 2012). It is also
common to experience longer periods of incapacitation and care. Eighty-
ve per cent of men in the Arroya Bandera Aché had been ill or injured for at
least a month over a seven-year period and would not have survived with-
out care from others (Hill and Hurtado 2009). Willing care, regardless of the
probability of survival, makes a signicant dierence to recovery. Healthcare
provisioning signicantly reduced juvenile mortality amongst the Shiwiar
forager-horticulturalists, with half of the adults being incapacitated and
unable to nd food for themselves for at least a month (Sugiyama 2001;
Sugiyama 2004).
Sharing health by caring and provisioning the ill and injured is only one
aspect of a life fundamentally based on sharing in these societies. Sharing
of food resources has a function for survival, minimising any individual’s
risk of starving themselves or being unable to provide for infants, and
enhances survival of the whole group in similar ways (Ringen, Duda, and
Jaeggi 2019). Most hunter-gatherers hunt collaboratively, and share the pro-
ceeds with other members of the group that they live with, and not just their
kin, according to their needs. This means that, though some individuals tend
to benet more than others, overall everyone benets from being buered
from days when they fail to bring home enough food for themselves or their
family (Chapais 2013). The vulnerable consistently receive more food than
the most able (Wood and Marlowe 2013). Meat, in particular, is shared both
within families and between them, according to needs rather than previous
contributions or status and despite how hungry the giver may be (Dyble
et al. 2016; Wood and Marlowe 2013). Sharing food, however, is also about
promoting harmony in social relationships (Lavi and Friesem 2019) and
demonstrating self-control on others’ behalves (Green and Spikins 2020).
A reliance on other people may not be as obvious in modern industrialised
societies as it is in modern foragers but it is no less signicant. We are all
physically vulnerable at dierent stages of our lives, from infancy, preg-
nancy and childbirth, illness or injury and old age. More than this, we are
also emotionally vulnerable (discussed in Part 2), and susceptible to loneli-
ness, anxiety or the eects of unfairness or exclusion. The origin of these
vulnerabilities lies in those societies that rst depended on each other to
survive. The more mutual survival depends on motivations to respond
110 HIDDEN DEPTHS
to others’ vulnerabilities and others’ response to our own needs, the greater
human sensitivities to others’ welfare must become.
It might seem surprising that changes in emotional motivations seem to
predate changes in complex cognition, particularly as we like to believe that
our human intelligence sets us apart from other animals. As we have seen, it
was after 2 million years ago that humans developed new and highly eec-
tive types of collaboration, eectively working ‘like a single predatory organ-
ism’ in their new hunting niche (Whiten and Erdal 2012). It is easy to assume,
working from our own ideological norms, that this collaboration was built
primarily on strategic goals, better communication or abilities to plan. How-
ever, in reality, moving into a new ecological niche was much more about
sharing, mutual vulnerability and a human response to vulnerability.
That there is clearly no simple progression of more recognisably human-
like forms might also be surprising. Yet the anatomical record demonstrates
alternative pathways, from those of the paranthropines to that of Homo nal-
edi, and we cannot help but wonder what other branches of ‘human’ remain
to be discovered or, indeed, perhaps might never be found.
Further, whilst it seems reasonable to conclude that a sensitivity to others
and emotional motivations to help are perhaps the most signicant devel-
opment in our evolutionary past, does it follow, however, that this capacity
elevates humans above other animals? Given that a widespread willing-
ness to respond to vulnerable infants in the group, to share risks and food,
and to care for the ill and injured is shared, at least with African wild dogs if
not other social animals besides, this seems dicult to argue. Perhaps those
traits such as complex language or cultural learning that mark us out as dif-
ferent are less critical to our origins than those that might be distinctive for
an ape, but link us to other species rather than dividing us from them. Per-
haps, as Anderson notes, ‘“we” (or at least those of “us” of a Western cultural
tradition) urgently need to overcome the still lingering idea that being
human means rising above our worldly, and indeed our animal existence’
(Anderson 2019: 66).
There are, of course, many questions remaining. It is dicult to determine
how dependent the earliest societies were on care for vulnerable adults for
their survival, for example. Certainly, such care may have been part of their
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 111
abilities to confront predators and hunt dangerous animals whilst living
with the consequences in terms of injury risks. Care for vulnerable adults
almost certainly played a role at some point in our evolutionary past in
allowing longer lifespans and the involvement of grandparents in infant
care, as well as in the cultural transmission of knowledge, but whether
this happened early in our evolutionary origins or rather later remains to
be explored. We may imagine that care extended across a range of vulner-
abilities, including not only physical vulnerabilities but also emotional or
mental health issues. However, the latter typically leave no surviving trace in
skeletal remains, making this dicult to determine. It also seems likely that
care played a social role as well as a practical one, not only forging strong
bonds but also promoting a sense of safety and trust that is essential to a
human willingness to act in others’ interests. This is, equally, a harder area
to assess from the material record (discussed in Chapter 3). Care for adults
made vulnerable through illness or injury is also likely to be intimately
related to care of vulnerable young or vulnerable elderly, though how these
types of care are related to each other remains to be understood. In modern
hunting-gathering societies, bone fractures increase substantially with age.
More elderly members of groups are less physically able to take on some for-
aging tasks, for example, but nonetheless bring important knowledge and
skills in less physically demanding areas such as in tool making (Stieglitz
et al. 2020). It is not only care for adults with temporary vulnerabilities but
motivations to care for anyone who is vulnerable that will have transformed
societies in important and, as yet, not fully understood ways.
Moreover, there is much to reect on. We cannot help but wonder whether a
new narrative of human ‘success’, as based not on individual performance or
intellect but on emotional connection, human vulnerability and response,
might cast some of our modern assumptions about human ‘value’ in terms
of competition or intellectual merit in a new light.
Conclusions
That care for adults who were vulnerable through injury or illness was a
signicant feature of our evolutionary origins is rarely, if ever, mentioned
in accounts of our human origins. Our own discomfort with vulnerability
may partly explain this apparent paradox. In many modern industrialised
cultures, a focus on being independent and competitive can make any
112 HIDDEN DEPTHS
dependence on others feel deeply uncomfortable. However, extensive evi-
dence for care for illness and injury, of which Shanidar 1 is only one example,
suggests that our early ancestors were people who cared deeply for each
other, and were prepared to go to great lengths on each other’s behalf.
These were populations for whom vulnerabilities and sharing responses
from others were common.
As we have seen in Chapter 1, there are adaptive explanations for increas-
ing signicance of emotional dispositions towards helping others and
responding to vulnerability. As well as being fundamental to being human,
the archaeological record for an increasing prevalence and intensity of care
suggests that changes in emotional dispositions were far more key to social
transformation than has been assumed. An apparently simple response, to
care for others in need or distress, becomes in humans an integral part of
how societies work, the so-called ‘glue’ that holds us together. Rather than
our intellectual capacity for language or technological skills making us
human, our emotional connections to others and tendencies to respond to
their vulnerabilities may have been more important.
Extended tendencies to focus on others, and be emotionally motivated
to act on their behalf, did not come without costs. Collaboration based on
emotional motivations comes at an individual cost of sensitivity to others’
distress. Furthermore, in an evolutionary context, the more interdependent
social communities became, and the greater investments made to helping
others, the more important it will have been to know who one could trust
– whose motivations were genuine, and whose were not. Here began our
worries and anxieties about what others think about us, and who we can
trust (explored in Chapter 3).
Key points
• After 2 million years ago, we see evidence for care for vulnerable adult
humans who suer illness or injury. This seems to be part of a critical
process of transformation in emotional motivations within early mem-
bers of the genus Homo and which includes motivations to help others
in other realms such as hunting, food sharing and infant care.
MATERIAL EVIDENCE: CARING FOR ADULT VULNERABILITIES 113
• This signicant transformation towards greater interdependence and
emotional motivations to respond to vulnerability may represent a shift
in response to ecological opportunities or changes, and shares similari-
ties with the emotional responses to other group members seen in ani-
mals such as social carnivores.
• More extended periods of care, and more complex cognitive planning
and knowledge involved in long-term care, appear later in human evo-
lution, particularly in archaic humans. If any dierences are apparent
between care in archaic and modern humans, they are subtle and prob-
ably related to cultural context rather than emotional responses.
• Care for vulnerable adults has potentially signicant implications for
biology, subsistence practices, social relationships, cultures and the
emotional connections within communities. The importance of such
care also suggests a reappraisal of our assumptions about key driving
factors in our evolutionary past.
114 HIDDEN DEPTHS
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CHAPTER 3
Trust, Emotional Commitments
and Reputation
Abstract
How did our uniquely human commitments to our loved ones
develop, and why are we so concerned about what feelings lie
underneath what other people do? In this chapter, we consider the
origins of our long-term emotional connections based on trust, and
how they lead to uniquely human sensitivities to what motivates
other people and how they feel about us.
As we have seen in Chapters 1 and 2, new types of emotional con-
nections, and new ways of collaborating to survive, emerged in early
humans after 2 million years ago. This was a time when changes in
emotional dispositions led to a greater willingness to share with,
and care for, a wider set of individuals. Archaeological evidence
demonstrates care for vulnerable adults, within the contexts of both
food sharing and of collaborative care for increasingly dependent
ospring.
(Abstract continued on next page)
How to cite this book chapter:
Spikins, P., 2022. Hidden Depths: the origins of human connection. Pp. 129–167. York:
White Rose University Press. DOI: https://doi.org/10.22599/HiddenDepths.d.
License: CC BY-NC 4.0
130 HIDDEN DEPTHS
The emergence of strong emotional bonds based on high levels of
give and take at this time laid the basis for human trust, emotional
commitments and love. Yet these long-term emotional connec-
tions also seem to have come at a price. The importance of knowing
who to trust brought with it pressures to be acutely focused on dis-
playing our genuine intentions (or hiding our less genuine ones),
and on identifying the genuine emotional motivations of others.
Considering the importance of relationships based on trust, and
with this emotional astuteness about who could be trusted, may
yield important insights into many debates about our origins. These
include the cultural transmission of ideas, the explanations for an
increasing concern with symmetry and the aesthetics of form in
stone tools after 2 million years ago, and the mechanisms behind
how people who thought dierently may have been integrated into
human populations.
Long-term relationships based on trust and a sensitivity to the emo-
tional connections underlying people’s words or actions may have
been much more important in our distant past than we have previ-
ously recognised.
(Abstract continued from previous page)
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 131
Introduction
Many highly evocative examples of European Ice Age art aect us emotion-
ally. Simply experiencing the depictions of lions at Chauvet cave (Figure 3.1)
seems to transport us to the time, place and mind of the artist who created
them, for example. Realistic depictions like these appear after 50,000 years
ago, not only in Europe but as far aeld as Indonesia. Debates about the
meaning of such depictions have continued for well over a hundred years.
However, beyond the specic meaning of any one painting or artefact, such
art also tells us about a uniquely human sensitivity to how others feel. Even
though all we are looking at is stone and paint, or even, perhaps, just an
Figure 3.1: Our sensitivity to others’ feelings and to who they are as a per-
son prompts us to feel transported into the mind and feelings of the artist
who created these lions from Chauvet cave, France, around 30,000 years
ago. Image from replica at Brno Museum Anthropos (Czech Republic).
Public domain, via Wikimedia Commons: https://commons.wikimedia
.org/wiki/File:Lions_painting,_Chauvet_Cave_(museum_replica).jpg.
132 HIDDEN DEPTHS
image on the screen or paper, we feel intimately emotionally connected to
the artist, despite the many thousands of years between us. We feel that we
are in some way in the moment, and in the mind, of whoever painted this
picture. We get a sense that the artist knew how we would feel in viewing
this image, at least on some level, despite the thousands of years and widely
dierent cultures and experiences between us. We also have some sense of
how they themselves felt when remembering these lions.
Our emotional brains are nely attuned to identifying not just what people
believe but how they feel and the emotions behind why they do what they
do. Yet, despite the complexity of these judgements, we scarcely notice we
make them. Every story, action and item of gossip is subject to our unthink-
ing judgement about its implications in terms of what people feel, and what
they might feel about us. We cannot help being driven to try to understand
what they mean about whether people are trustworthy or not, whether they
are on our side, and even what their emotional motivations mean about the
world as a whole. Because of this sensitivity, we are also almost inescapably
drawn to infer the emotions behind art, a topic we return to in more depth
in Chapter 5.
Why should it matter to be so attuned to others’ feelings and motivations?
Some of the explanations for our acute sensitivities to other people’s feel-
ings lie in changes in recent human evolution over the last 300,000 years
(discussed in Part 2). However, the origins of our attention to what lies
behind other people’s actions seem to lie much further back in time. The
interdependence within groups of early humans, as far back as 2 million
years ago, reected in their willingness to care for adults with vulnerabili-
ties (discussed in Chapter 2), seems to have triggered important changes
in emotional connections. We hardly imagine our distant ancestors as trust-
worthy. However, so much of what kept groups alive may have depended
on trust, whether that was raising vulnerable ospring and protecting them
from harm, nding food together or tackling dangerous animals (Spikins
2019). Only by caring deeply about others would early humans have been
motivated to help them when they were ill, share food with them, or risk
their own lives to defend them from predators. Such willingness to help risks
exploitation, however, perhaps from an individual’s ally or mate who might
abandon them in a time of need. Abilities to make the right choices about
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 133
people and to correctly judge others’ motivations and emotional commit-
ments towards us will have been increasingly important.
The signicance of trust to our evolutionary history may tell us something
important about why we are so acutely attuned to what other people
feel about us, and why it is not just social connections that we need to
thrive today but shared emotional commitments marked by genuine care
and trust.
Trust and a sensitivity to emotional motivations in human
evolutionary origins
Our human drive to understand the emotions behind other
people’s actions
When we consider how human minds and societies developed, we have tra-
ditionally paid a lot of attention to the signicance of our strategic social
thinking or cognitive empathy (see, for example, Dunbar 2003; Noonan et al.
2018), explained in Chapter 1. We often hear about the ‘social brain’ or theory
of mind, how unusually adept we humans are at understanding what others
believe and what they are rationally thinking, and how good we are at the
social understanding needed to maintain many social contacts. However,
the importance of our aective empathy, or emotional attunement to
others’ feelings, and how we use it to understand how they feel about us, is
often forgotten. This attunement to how others feel and why they feel this,
rather than simply to what they think or believe, may have been far more
important in our evolutionary past than we have recognised.
Clues exist today. Looking around us we can see a surprisingly com-
plex attention and attunement to the hidden depths of other people’s
emotional lives.
We are much more sensitive to the emotions of people around us than we
often imagine. As we have discussed in Chapter 1, how others around us
feel aects us deeply. We are acutely sensitive to heroism, cruelty or even
everyday kindness or harshness, for example (Keltner and Haidt 2003; Piper,
Saslow, and Saturn 2015). Even just hearing about acts of genuine com-
passion or heroism can inuence how we treat others around us and what
134 HIDDEN DEPTHS
we believe about the world. Acts of generosity tend to spread to people
down the line, as people feel dierently after hearing about or witnessing
them and ‘pay it forwards’ (Fowler and Christakis 2010). Moreover, we have
extraordinary levels of biological attunement to each other – the heart
rate and gamma brain wave oscillations of mothers and babies and cou-
ples even coordinate in tune with each other, as well as their emotions and
movements (Feldman 2017).
More than this sensitivity, however, we pay great attention to what other
people feel about us, or even might feel about us, and what their feelings
might mean. We have remarkable abilities to make highly accurate infer-
ences about other people’s intentions, even on the basis of the tiniest of
facial expressions or slightest of other indications of what feelings are hap-
pening ‘behind the scenes’ in others’ minds.
There have even been many changes to the human face since our split
with other apes which reect our need to display our feelings and identify
the feelings of others. These include the emergence of blushing and cry-
ing as signs of genuine emotions (Evans 2002), as well as changes in face
shape and appearance (Bastir 2018; Godinho, Spikins, and O’Higgins 2018;
Lacruz et al. 2019). We share a distinctive ability to both express and iden-
tify in others subtle expressions of vulnerability, sympathy or recognition
through movements of our eyebrows, for example, discussed in more detail
in Part 2.
Often without realising it, we constantly track the feelings and intentions
of the people around us, and how they might behave (Thornton, Weaver-
dyck, and Tamir 2019). We may think we pay attention to what people do
but, in fact, the hidden world of their feelings is often more important to
us. Research conrms that we are much less swayed by the outcomes of
people’s actions then we are by the emotional intentions behind them, for
example (Yudkin, Prosser, and Crockett 2018). We may feel more positively
inclined towards an elderly person who kindly gives sweets to a child than
to someone wealthy who gives substantial funds to a major charity, even
though the outcome in the former case may not be all that positive and, in
the latter, may make a substantial contribution to people’s lives. We even
feel more comfortable talking to a stranger who displays their caring nature
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 135
through owning a pet dog than we would if they were by themselves, for
example (McNicholas and Collis 2000). By this small acknowledgement of
their emotional need for a pet, they seem more trustworthy. Our complex
pictures of the emotional motivations of other people even extends to how
they treat not only other people or even animals but also inanimate things
(discussed in Chapter 5).
The eorts our brains make, behind the scenes, to keep track of others’ feel-
ings and what they might mean extend into having profound eects on
our long-term relationships. We may love our children unconditionally, or
at least aspire to, but, in our adult relationships, how our friends, partners
or other people important in our lives feel about us matters deeply. We
keep extraordinary track of the motivations of people close to us through a
constant set of mathematically founded assessments of their ‘trust metric’,
or the extent to which we understand that they will act in our interests above
theirs, for example (Gottman 2011). However much we value rationality in
our business world, amongst our partners and friends we are unimpressed
if they are not prepared to be irrationally driven to sometimes put our needs
above their own when it matters for us (Jordan et al. 2016; Manapat, Nowak,
and Rand 2013). Further, many micro judgements lie at the heart of long-
term relationships. In these relationships, as we trust someone more, we
become increasingly more willing to be generous, and more comfortable
with giving to another person without expecting anything in return (Mana-
pat, Nowak, and Rand 2013).
We start to make these judgements about what motivates other people
from an early age, and they become so routine that we barely notice them.
As we have seen in Chapter 1, these judgements begin in early childhood,
when we are no longer duped by apparently kind acts but become much
more aware of what feelings lie behind what other people do, and why they
matter. This is the point when, even as young children, we help others dis-
criminately, deciding how much eort to put in to help, or even whether to
put in any at all, according to our estimate of the person needing help. From
childhood, it is not sucient just to track what others do. We also need to
know what their underlying emotional motivations are. Even in the play-
ground, we often make decisions to resist bullies and help those genuinely
in need which may not be in our own immediate short-term interest.
136 HIDDEN DEPTHS
We cannot help but wonder why we should devote quite so much time and
eort to understanding what emotions lie underneath others’ behaviour,
and what they might mean.
We do share a certain sensitivity to others’ motivations with many highly
social animals. Chimpanzees, for example, can remember favours that have
been done to them for at least six months (Schino and Aureli 2010). Domes-
tic dogs make judgements about people who have either helped or refused
to help their owners, and will not accept food from the latter (Chijiiwa et al.
2015). Being a social animal involves being astute about how your fellows
are behaving and how it might aect you. It also involves being able to han-
dle emotions rather than immediately act on them, such as through over-
coming the frustrations of having to share food, or controlling impulses to
be aggressive (Green and Spikins 2020; Marshall-Pescini, Virányi, and Range
2015). However, our seeming obsession is dierent. Only humans build up
a complex picture of the emotional motivations of people around us on the
basis of a whole myriad of behaviours, not just those we see in front of us
but also stretching into the past.
The unique problems faced by early humans may give us important insights
into why trust became so important, and why we care so much about what
lies behind what other people do and how they feel about us.
Why early human interdependence made a good reputation matter
As we have seen in Chapters 1 and 2, early humans from about 2 million
years ago survived dangerous predators, brought up vulnerable young
and found food because they depended on each other. Archaeological evi-
dence demonstrates an increasing tendency to care for ill or injured adults
as well as increasingly vulnerable and dependent children, alongside col-
laborative hunting of increasingly large and dangerous animals and sharing
of food resources.
Early human groups at this point took a dierent pathway from other apes,
as we discussed in Chapter 1. Non-human apes may be socially clever,
but they are largely self-focused, with their main emotional bonds being
between mothers and their ospring. However, early human communities
needed to be far more collaborative to survive, and changes in emotional
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 137
Figure 3.2: Judgements of reputation within peer-to-peer alliances are
relatively simple (left) whereas within collaborative groups judgements
of reputation with regard to many potential allies or even the group as a
whole are far more complex (right). Penny Spikins, CC BY-NC 4.0.
connections are likely to have played a key role in enabling this. By being
willing to be generous to others in their group, and to depend on others’
generosity in turn, they will have been able to reduce their individual risks
at a time of increasing environmental unpredictability (Grove 2011). Shar-
ing hunting risks, food, infant care and caring for the ill and injured made
human groups far more resilient to the vagaries of resource shortfalls, inju-
ries or individual misfortune (Gurven and Jaeggi 2015). It was also in these
collaborative contexts, where caring for others was key to bringing up vul-
nerable young, to nding and sharing food, and to looking after vulnerable
adults, that the strength of our human emotional connections, and even
love, emerged.
Two key transformations had to take place. Firstly, collaboration had to hap-
pen across the whole group, rather than just with particular allies as we see
with chimpanzees (Figure 3.2). This meant that being a valuable and trusted
group member began to matter (Tomasello and Vaish 2013). Secondly,
the depth of collaborations, and the extent of give and take anyone might
expect from others, had to increase. From calculated exchanges typical of
other apes, early humans had to develop much more in-depth commit-
ments, such as in taking risks to nd resources or to defend the group from
predators, or in shared care for vulnerable young (Figure 3.3).
138 HIDDEN DEPTHS
These transformations brought new levels of collaboration but, also, new
problems. As we have seen in Chapter 1, whilst it makes simple adaptive
sense to help out members of one’s family, helping out non-family mem-
bers depends on mutual generosity and some kind of assurance that one’s
eorts will be repaid, if not by that person then by someone else. Ances-
tral apes would be fully capable of deception, opening up possibilities for
exploitation. The more interdependent people became, and the more sur-
vival depended on extensive ‘give and take’, so the more serious would be
the consequences of being exploited. There are many situations where a
small amount of help from someone who genuinely cares can make a big
dierence to survival, of which temporary illness or injury is just one exam-
ple. But how could such help be ensured? Without laws or formal repercus-
sions, what would stop a friend, mate or ally from abandoning someone
with a serious injury in time of need?
Figure 3.3: Relationships based on strategic selsh motivations (left) show
lower levels of give and take (denoted by thinner lines) and lack trust
(denoted by T) than those based on genuine caring and mutual generos-
ity (right). Penny Spikins, CC BY-NC 4.0.
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 139
Emotional commitments, fuelled by trust and abilities to discern who is or
is not genuine, solve this problem (Spikins 2019). Genuine emotions act like
an insurance policy, forcing other people to pay a price in terms of emo-
tional pain if they do not act in the best interests of someone they care
about. In this sense, emotions handcu people to act on others’ behaviours
before their own, and vice versa should the situation be reversed. We all
experience this most acutely when we talk about the eects of love, or sci-
entically phrased ‘strong emotional bonds’. Love motivates us to sacrice
ourselves for someone else, and when something bad happens to them
or we let them down love hurts. The extremes of joy and pain through our
emotional connection to people we love create strong bonds, resilience to
life’s challenges and high levels of give and take. However, our tendencies
to care can also be exploited, and the more we care about other people
the more we are willing to sacrice and the more we might lose. The more
attuned we can be to identifying genuine motivations from fake ones, and
at displaying our own genuine intentions, the better we can be at develop-
ing relationships based on mutual trust and so the better we are protected
from deception or cheating. For this reason, early human interdependence
brought with it selective pressures on displaying and identifying genuine
emotions and tracking others’ reputations, with genuinely caring about oth-
ers working almost like a type of currency to ensure willing generosity from
them in turn (Homan, Yoeli, and Nowak 2015; Jordan et al. 2016; Rand and
Nowak 2013; Spikins 2015a).
The more important collaboration became to survival, and the more
interdependent human groups became, the more important relationships
based on trust and long-term emotional commitments were. This, in turn,
meant that having, displaying and being able to identify genuine kindness
became more important also. The potential for exploitation also became
greater, of course. The need to express and identify genuine motivations,
and the possibility of cheating and exploitation, can almost be seen like the
escalation of an arms race, to which we credit both our capacities for love
and our all-too-present concerns with who to trust and what others feel
about us.
We can see the role of reputation aecting other people’s emotional will-
ingness to help all around us even today. Examples abound in modern
140 HIDDEN DEPTHS
hunter-gatherers, as well as in our own society. Amongst the Martu of the
Australian Western Desert, for example, the most genuinely generous hunt-
ers are the ones that are most favoured as hunting partners (Bird and Power
2015) and, amongst the Aché of Paraguay, the most genuinely generous
hunters were most willingly looked after when ill or elderly (Gurven et al.
2000). It is easy to imagine that these judgements might simply be about
actions but instead they rest on judgements of genuine feeling. Amongst
the Jo’huansi of the northern Kalahari, for example, too large a gift is treated
with suspicion – it might indicate that someone wishes to ingratiate them-
selves, rather than genuinely caring (Wiessner 2002). Our intuitive judge-
ments about the feelings behind people’s actions even aect who we nd
attractive. Even in Western industrialised societies, more altruistic men tend
to be rated as more physically and sexually attractive and desirable as dates
than those who are less altruistic (Jensen-Campbell, Graziano, and West
1995), and more genuinely altruistic people also have higher mating suc-
cess over the long term (Arnocky et al. 2016). It is not what people do that
matters in highly collaborative human groups but the hidden depths of the
emotional motivations underlying why they do it.
We tend to imagine that early humans were cunning rather than kind but,
perhaps surprisingly, in a climate of trust within small cohesive societies,
genuinely caring about others can be a more successful strategy than
just being socially clever. We may imagine that collaboration depended
on being socially clever, but social astuteness alone does not foster eec-
tive collaboration. Strategic social thinking can add ‘fuel to the re’ of com-
petition, promoting unethical behaviour (Pierce et al. 2013) and enabling
manipulation. Emotional motivations to care about others’ wellbeing can
be far more important to how people work together eectively than being
socially clever (Smith et al. 2017; Stellar et al. 2017). Our willingness to pun-
ish those who cheat or who are exploitative also acts like a measure of ‘polic-
ing’ people who are manipulative or purely self-interested (discussed in
Chapter 1). Moreover, it is not always an advantage to have more complex
social thinking or theory of mind abilities. Higher levels of perspective-
taking contribute to anxiety about what others are thinking and have been
associated with psychosis (Brosnan et al. 2010). Further, when it comes
to making friends, we are often more willing to trust people who do not
delve too deeply into what others are thinking about them (Jordan et al.
2016; Spikins, Wright, and Hodgson 2016). Being too socially intelligent
can backre if others are focused on your trustworthiness and suspicious
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 141
of social astuteness. We may imagine a ‘successful’ early human as rather a
self-centred and even cutthroat type of person, successful perhaps through
their Machiavellian tactics, but such ideas are purely our own assumptions
(Winder and Winder 2015). The nature of collaboration argues that being
kind may have mattered much more to success than being cunning.
Trust, emotional commitments and the price to pay
for caring about reputation
Collaboration based on emotional commitments, rather than on simple
agreements or loose alliances, may have been even more key to human
evolutionary success than we imagine. Relationships based on trust meant
that collaborative groups could hunt larger and more dangerous prey, as
individuals would be willing to risk their lives for others and also to care
for injured adults. It also meant that vulnerable young could take longer to
reach adulthood, given the security of many adults to care for them, and so
could learn more in the process.
However, there was a price to pay for a dependence on such relationships.
Firstly, depending on the generosity of one’s socially astute peers for one’s
own survival meant that the social and emotional world got a great deal
more complicated. Secondly, an awareness of one’s reputation in oth-
ers’ eyes brought with it emotional vulnerabilities that continue to plague
us today.
There are costs in terms of brain power needed to keep track of who to trust.
It takes a lot of cognitive eort to fully understand others’ emotional motiva-
tions, or their emotional reputation, as this depends on building up a pic-
ture over many dierent moments, not just one individual instance. With-
out building up our understanding of someone else, we are easily duped
by behaviours that appear to be helpful but may hide selsh or harmful
intentions. Moreover, whilst chimpanzees only need to track peer-to-peer
relationships (single sets of allies), people are also concerned with others’
group morality, the extent to which they want to contribute to the wellbeing
of the whole group (Tomasello and Vaish 2013). Understanding what some-
one’s behaviour might mean about their intentions towards you is already
complicated enough, but understanding what their behaviour means about
their intentions and motivations with regard to the whole social group is
even more complex.
142 HIDDEN DEPTHS
There is good reason to argue that it was the heightening stakes on
making the right decisions about who to trust that prompted selective pres-
sures on a better understanding of what other people think or feel, includ-
ing about each other (Homan, Yoeli, and Nowak 2015; Rand and Nowak
2013; Spikins 2015a). Quite simply, early humans needed to understand a
great deal about what others thought and felt, not only about them but
about everyone else, and to get better at building up a picture of others’
feelings and actions over many instances. Moreover, these kinds of pres-
sures may have been key to driving accelerated human intelligence and, as
we have noted in Chapter 2, it may not be so surprising that even the small-
est brained species of early human add enlarged brain areas responsible for
social and emotional processing.
These heightened stakes also set the scene for painful emotions such as
guilt or shame, which prompt us to adhere to moral norms. After all, pain-
ful though such feelings may be, people tend to trust us more when we are
visibly guilty or ashamed for our transgressions. Our emotional self-punish-
ment is dicult to fake, and provides some reliable evidence to others that
we would nd it hard to exploit them. These feelings hardly make our own
lives easier, though, and can often become debilitating. The importance of
reputation within our social relationships means that we are left with deep-
seated concerns and vulnerabilities around what people think about us, and
who to trust, making us vulnerable to shame and depression. It may be a
price worth paying for deep-seated connections, kindness and support in
hard times, but it is not an easy one.
The signicance of trust, emotional commitments and a
concern with reputation to key issues in human origins
The importance of trust, emotional commitments and reputation to early
human collaboration may give us new insights into some of the key ques-
tions about our early origins.
Being kind rather than being cunning
We often base our interpretations on the assumption that people who were
socially clever were the most successful in our evolutionary past, rather than
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 143
those who were emotionally kind or good at forging relationships based
on trust.
It is not dicult to see why we have made this assumption. Our preconcep-
tions about what must have been important for success may have played
a role (discussed in the introduction to this volume). Moreover, drawing a
straight line between our nearest relatives, chimpanzees, and ourselves may
be another inuence. As we have seen in Chapter 1, imagining our ancestors
as existing part way along a continuum between non-human ape and mod-
ern human easily prompts us to ignore the importance of interdependence,
emotionally based collaboration, and response to vulnerability to how early
humans survived.
There are also other reasons why being socially clever, rather than kind, has
been emphasised in our evolutionary origins. Evidence from changes in
the size and shape of the human brain through time seem to point in the
direction of increasingly large, and so socially challenging, human groups
rather than small and cohesive ones. Social understanding or theory of
mind abilities are key to keeping track of many individuals within the type
of large-scale social network such as we imagine characterised an early
human past (Lewis et al. 2011; Noonan et al. 2018). Increases in prefrontal
(neocortex) size through human evolution, alongside comparisons with
other species, were taken to imply a progression towards increasingly
large human social networks (Lehmann and Dunbar 2009). On this basis, it
appeared that selection pressures on the ‘social brain’ and so our abilities to
manage complex social situations, drove expansions in human intelligence.
There are problems with the idea of increasingly socially intelligent humans
adapted to ever larger social networks, however. Whilst neocortex size does
increase throughout human evolution, this may not be primarily indicative
of increasing group sizes, and with this the need to negotiate relationships
with many people, but rather of a need to forge closer and more trusting
relationships with a few.
Firstly, the relationship between neocortex size and group sizes has been
called into question, with clear correlations dicult to identify (Lindenfors,
144 HIDDEN DEPTHS
Wartel, and Lind 2021; Miller, Barton, and Nunn 2019). Secondly, there is little
archaeological evidence for either large groups or large social networks prior
to 300,000 years ago, and archaeological and genetic evidence more clearly
support small close-knit groups rather than large complex social communi-
ties, as discussed in Part 2. An increasing neocortex size may have more to
do with emotional understanding and social emotional relationships than
with simply being socially complex. Theory of mind (understanding what
other people think) and emotional understanding (aective empathy) use
somewhat dierent parts of the brain (Stietz et al. 2019) but both involve
increasing activity in the neocortex.
Social networks and social intelligence, in terms of keeping track of many
people, may be a much less signicant factor in our evolutionary history
than we imagine. We can ‘keep track of’ many dierent relationships with-
out these relationships necessarily having any real depth or signicance in
our lives. Some ‘relationships’ that involve theory of mind and perspective-
taking do not involve any meaningful emotional interaction. For example,
chimpanzees use their social abilities to pay close attention to the calls of
neighbouring groups and what they mean about their politics (Sapolsky
2017), paying more attention to socially surprising sounds (such as submis-
sion by a dominant individual to a lower-ranking one) (Figure 3.4). Ravens
use their social intelligence in the same way (Massen et al. 2014). In each
case, this demands social cognitive complexity. In similar ways, in mod-
ern societies we use our social competence to keep track of relationships
between pretend characters, which feel like they are real but are similarly
not a meaningful part of an alliance network (Lather and Moyer-Guse 2011).
None of these relationships provides allies who are there when needed.
If we redress the balance and take on board the signicance of trust, emo-
tional commitments and reputation to our human origins, we may contrib-
ute to several key debates – from early cultural transmission knowledge to
the explanations for a concern with aesthetics to the mechanisms promot-
ing inclusion of dierent minds into early societies.
Reecting on the cultural transmission of knowledge
Most authors agree that the capacity to pass on knowledge from one gener-
ation to another, or cultural transmission, is a signicant evolutionary step in
our origins. However, in terms of explaining this important transformation,
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 145
Figure 3.4: A group of chimpanzees at Kibale National Park, Uganda, stop
near the boundary between groups and listen carefully to the calls within
their neighbouring group for several minutes before moving on. Photo
copyright John Mitani, reproduced with permission.
we have tended to focus on the role of capacities for social communication,
including language.
There has been a tendency to assume that teaching and learning are primar-
ily about eective communication. From this perspective, passing on knowl-
edge from one generation to another comes about through being able to
communicate that knowledge eectively, both technically in terms of lan-
guage and socially in terms of understanding of how others think. However,
cultural transmission of important innovations and knowledge may be one
example of the often-underestimated role of trust and emotional commit-
ments. Emotional dispositions and abilities may be more critical to learning
and teaching of skills than we imagine.
Abilities to teach new skills to others (particularly stone tool production)
have been related to perspective-taking capacities (Shipton 2010). How-
ever, emotional motivations towards others’ wellbeing may be as much,
if not more important, in learning. There is good reason to suggest that
146 HIDDEN DEPTHS
motivations to teach skills and a sense of safety needed to learn are most
dependent on emotional connections, rather than cognitive skills. Those
social species that are most collaborative and most emotionally motivated
to care about ospring seem most disposed to teach skills to their young,
rather than those that are most socially or cognitively clever. We might
expect our nearest relatives, the chimpanzees, with the highest non-human
theory of mind abilities, to be the most adept at teaching skills to the young.
However, young chimpanzees typically learn only by copying adult behav-
iour rather than by being actively taught. It is amongst far more distantly
related collaboratively breeding tamarins that we see evidence of teaching,
including vocalisations, amending food transfers according to skills and
sculpting of behaviours (Snowdon 2011). Cooperatively breeding meerkats
may not technically be clever but they teach foraging skills to the young,
such as by stunning scorpions to allow young to learn how to kill them
(Thornton and McAulie 2006). Moreover, bonding hormones play a key
role in this activity. Increasing levels of oxytocin in meerkats cause increased
eorts to teach skills (Madden and Clutton-Brock 2011). On a phylogenetic
level, teaching appears to be more associated with cooperative breeding
and emotional motivations to care for other group members than theory of
mind (Thornton and McAulie 2015).
Changes in emotional dispositions as early humans become more collabo-
rative may have had a far greater impact on facilities to learn new skills and
pass on cultures than we think. We have tended to assume that more com-
plex technology associated with the origins of Homo, which must have been
taught across generations, was a product of increasing social understand-
ing, more complex theory of mind abilities, and so abilities to teach oth-
ers, for example. Changing emotional dispositions, aecting motivations to
share knowledge, may have been equally, if not more, important.
Reecting on the inuence of emotional reputation on attention to
the aesthetics of artefact form
The importance of emotional commitments may also cast light on ques-
tions of the earliest concern with aesthetics and symmetry.
Of all artefacts, it is perhaps stone tools that we most tend to associate with
being purely functional. However, even these artefacts may demonstrate
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 147
quite how sensitive our complex emotional brains were, even as far back as
nearly 2 million years ago.
It is handaxes, or bifaces, in particular that have attracted attention for their
potential to inform us about early human emotional capacities. Handaxes
begin to appear in the archaeological record after 2 million years ago,
alongside increased meat eating. They were almost certainly largely used
to butcher meat, remaining in use for over a million years. Research into the
form of handaxes or bifaces argues that these carefully formed stone tools
may demonstrate a certain sensitivity to reputation in their construction
(Green and Spikins 2020; Spikins 2012). Attention has been drawn to these
artefacts as they demonstrate a concern with symmetry and the aesthetics
of form in their construction, usually complying with what appears to be a
mental template of what a nished tool ought to look like in terms of a typi-
cal teardrop symmetrical shape (Figure 3.5).
Figure 3.5: Photograph of a handaxe or biface from Olduvai, dated to around
1.2 million years ago, illustrating attention to symmetry and the pleasing
aesthetic form of these artefacts (on display in the British Museum). John-
bod, CC BY-SA 3.0, via Wikimedia Commons: https://commons.wikimedia
.org/wiki/File:Olduvai_handaxeDSCF6959.jpg.
148 HIDDEN DEPTHS
Two particular characteristics of bifaces suggest that they may have played
an important role as signals of genuine emotional motivation. Firstly, by
imposing an aesthetically pleasing symmetry on an artefact that may be
used by others, early humans may have been demonstrating their other-
focus – the extent to which the feelings and wellbeing of those around them
demonstrably mattered to them. Secondly, early humans may also have
been signalling their abilities at inhibitory control, or overcoming frustra-
tion (Green and Spikins 2020; Spikins 2012). Certainly, it is far more dicult
to impose a preconceived form on a stone tool than simply to create a sharp
edge. Imposing the classic teardrop shape of a biface a int core demands
considerable inhibitory control (or what we might more prosaically call
patience or self-control).
Both of these capacities are plausibly important to collaborative social
relationships and liable to others’ judgements. Any species that becomes
more socially collaborative also needs to develop increased inhibitory con-
trol – the capacity to withstand motivations to act, particularly in one’s own
interests. We use inhibitory control, or patience, when we share food rather
than ‘giving in’ to the temptation to eat it all ourselves. Being able to act
prosocially in response to others’ needs demands not only empathy but also
inhibitory control – our capacity to handle emotions. When we see someone
in pain, for example, we feel an empathetic response, particularly if we care
about them. Without being able to exert some self-control over our emo-
tions, our own empathetic feelings can be overwhelming. Feeling empathy
only leads to compassionate helping behaviour if we can handle dicult
emotions and overcome tendencies to simply act impulsively.
Evolved capacities for impulse control (self-control/inhibitory control),
or more prosaically patience, vary between dierent species, as well as
according to any animal’s experiences. Sometimes, evolved selective
pressures to handle emotional impulses arise simply from the type of
resources dierent animals exploit. Predators need inhibitory control to
resist temptations to ‘pounce’ until the right moment, for example. There
can also be subtle pressures that inuence dierences between closely
related species. Amongst New World monkeys, for example, common
marmosets depend on exploiting sap that oozes slowly from trees and are
more ‘patient’ than cotton top tamarins, which more predominantly exploit
quick-moving insects, requiring greater impulsivity (Stevens, Hallinan, and
Hauser 2005).
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 149
For highly social animals, getting along with others often demands a need to
withstand immediate impulses, such as desires to snatch food from others,
to hit back or even to run away. Social-living primates, such as our nearest
relatives, chimpanzees and bonobos, typically show high levels of self-con-
trol, for example. Chimpanzees and bonobos are able to wait for a greater
food reward rather than impulsively take what is immediately on oer,
suggesting comparable abilities in our shared ancestor (Rosati et al. 2007).
Social carnivores are particularly adept at impulse control as they depend
so intimately on high levels of collaboration for survival (Marshall-Pescini,
Virányi, and Range 2015). Wolves are able to share food, which entails with-
standing the frustrations of being hungry themselves in order that those
they care about can eat (Dale et al. 2017). Moreover, although conicts erupt
often in wolf packs, actual violence is rare, with impulse control allowing
wolves to focus more on a reprimand and typically stop short of actual seri-
ous harm (Marshall-Pescini et al. 2017). In social mammals, play performs an
important function in fostering emotional regulation, providing an arena
to safely practise frustrations (Beko 2001; Linsey and Colwell 2003; Palagi
et al. 2016). In chimpanzees and bonobos (Palagi 2006) and wolves (Cordoni
2009), as well as in humans, social play extends into adulthood.
Self-control in humans shares similar features to that in other animals
(Miller et al. 2010). However, we also have extra levels of emotional regula-
tion. We can also draw on our conscious self-awareness of how we feel, and
our capacities to label (or ‘tame’) our feelings, as well as being able to use
conscious strategies to resist temptation (Hobson 2002). By bringing our
emotions into awareness, sharing them with others, and rationalising and
reframing our emotional experience, we can use our gut feelings as well as
our rational thinking to make decisions (Damasio and Dolan 1999).
Capacities for self-control and emotional regulation have far-reaching inu-
ences on human lives, aecting social relationships, achievement, and pro-
pensity to anxiety and depression (de Ridder et al. 2012; Joormann and Got-
lib 2010; Tangney, Baumeister, and Boone 2004), and predicting academic
performance better than IQ (Duckworth and Seligman 2005). Higher-level
controls on impulses also make it possible to delay gratication over consid-
erable timescales, for example saving money today for a pension many dec-
ades in the future. More than this, however, our abilities to withstand being
carried away by our emotions allow us to translate the intensity of feelings
we have for those we love to help them in pain, loss and grief.
150 HIDDEN DEPTHS
Though it takes extra eort and inhibitory control to overcome the frustra-
tions involved in imposing symmetry on the form of a biface, given the sig-
nicance of demonstrating one’s genuine motivations, this ‘costly signalling’
would almost certainly pay o in terms of fostering stronger social bonds
(Spikins 2012). In modern, highly collaborative societies, material displays of
genuine generosity and inhibitory control in giving away food even when
hungry have been shown to have rewards in later life through the willing-
ness of others to help at times of illness or inrmity (Gurven et al. 2000).
Conversely, material displays of impulsivity, at least in adults, are typically
treated with a certain disdain and loss of status, as seen amongst the Inuit
(Briggs 1970). Almost everything we do betrays how we feel, and the way in
which we create and use objects around us is no dierent. Whilst we tend
to focus on how more complex stone tools, such as handaxes, gave early
humans who used them a technological advantage over other hominins,
their ability to display subtle messages about generosity or trust may have
been equally if not more important. Not only can subtle messages in the
creation and use of material things send signals about positive reputation;
they may also perform a role as signs of comfort, safety and familiarity that
might promote physiological safeness and increase condence to explore
(discussed in Chapter 7).
Of course, there may be far more to handaxe symmetry than simply dis-
playing positive emotional capacities to others who were sensitive to such
indicators. Certainly, an irrational concern with the aesthetic form of bifaces
has been a source of much debate (Gowlett 2011; Gowlett 2020; Hayden
and Villeneuve 2009; Hodgson 2015; Kohn and Mithen 1999; Lycett 2008;
McNabb and Cole 2015; Nowell and Chang 2009; Wynn and Gowlett 2018).
Nonetheless, much like cave art many thousands of years later, it is clear that
these subtle signs of inner emotions can have powerful inuence.
A sensitivity to moral reputation may also be part of social processes that
fostered the inclusion of diverse cognitive styles in the evolutionary past.
Reecting on a sensitivity to emotional motivations and the
integration of dierent minds
An understanding of the signicance of relationships based on trust and of
judgements of reputation may also contribute to our understanding of the
mechanisms driving inclusion of people with dierent minds within societies.
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 151
As we discussed in the introduction to this volume, all too often we impose
an idea on the past of there being a simple progression in human evolu-
tion from one individual being to another, when the real story is far more
complex. We know that human populations are not really many examples
of a single ‘ideal’ mind but are made up of many dierent minds that work
together, but we easily forget this when we discuss our evolutionary past.
The concept of a progressively better individual through time tends to easily
suppress our understanding of the signicance of diversity to human evo-
lutionary success.
One particularly important example of how the interaction between dier-
ent minds may have contributed to our evolutionary history comes from
research on autism. Few people t into the mould of having what we might
think of as a ‘normal’ mind, and the dierences associated with autism pre-
sent us with one of the most interesting, important and hotly debated areas
of cognitive dierence.
Denitions of autism have changed over the years. Nonetheless, there is a
general consensus that people who we say have an autism spectrum con-
dition (ASC) tend to display a constellation of traits related to how they
perceive the world and their social perception. Individuals with ASC tend
to lie at the extreme of perceiving and thinking in terms of high levels of
detail (Happé and Frith 2006), and in terms of rules and systems rather than
intuitive understandings (Baron-Cohen and Lombardo 2017). Their strategic
social thinking is limited, and they tend to have only low levels of theory of
mind (being more likely to fail at the level of second-order theory of mind,
i.e. ‘Y believes that X believes this’; Baron-Cohen 1989). Whilst, in the earliest
cases of autism, the term implied a highly debilitating condition, today only
about 30% of cases of ASCs are associated with intellectual impairment (Ios-
sifov et al. 2014). Autism without intellectual impairment is more common,
and is often seen as more of a dierence than a disability, bringing with
it both talents and vulnerabilities (for a more detailed review, see Spikins
2009; Spikins, Scott, and Wright 2017; Spikins, Wright, and Hodgson 2016;
Wright, Spikins, and Pearson 2020).
For many years, it was assumed that autism was simply a disorder, and
that autistic individuals would not have survived in the societies of the far-
distant past (Bednarik 2013; Bednarik 2016; Pickard, Pickard, and Bonsall
2011). However, relatively recently genetic evidence has proved that this
152 HIDDEN DEPTHS
assumption was wrong. Some of the variants of genes associated with traits
related to autism are present across primates, being identied in macaques,
for example (Yoshida et al. 2016). Autistic traits have also been recorded in
chimpanzees (Faughn et al. 2015). Autism seems to be an essential part of
that evolvability of the human gene, that is, its capacity to adapt. Moreover,
autism has been subject to positive selection (Polimanti and Gelernter 2017)
and there also seems to be a proliferation of genes associated with autism
in relatively recent evolution (Nuttle et al. 2016). Not only were individuals
with ASC present in the past, but there appears to sometimes have been
certain advantages to the condition.
We will probably never identify any individual archaeological artefact made
by someone who we would now identify with ASC. However, there are some
clues as to the involvement in Palaeolithic societies.
How individuals with ASC interact with the material world around us today
show subtle dierences (Spikins, Scott, and Wright 2017; Spikins, Wright,
and Scott 2017; Wright et al. 2021). A far greater percentage of individuals
with ASC today have extraordinary talents in realistic depiction as a direct
result of their enhanced detail focus, for example (Spikins, Scott, and Wright
2017). Extraordinarily talented autistic artists are well known; however,
a tendency to show greater talent in realistic depiction is seen across the
whole population of individuals with ASC. Furthermore, individuals with
ASC tend to be drawn to creating and owning highly technological objects
and ones made with a high degree of precision, a trait that enhances their
abilities to produce highly specialised technology (Spikins and Wright 2016;
Spikins, Wright, and Hodgson 2016).
A focus on technology and detail may have been particularly important
to the ability of past hunting and gathering populations to survive in cold
and highly risky environments. As we see in the modern Inuit today, com-
plex technology is essential for survival in such situations. In these particu-
lar contexts, of which Ice Age Europe is a particularly good example, the
skills associated with autism may have been particularly valued. Similari-
ties between highly realistic depictions in European Upper Palaeolithic art
and that of talented autistic artists today are probably explained by the
involvement of autistic individuals in producing some of the art but also,
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 153
perhaps more importantly, inuencing the style of art (Spikins, Scott, and
Wright 2017).
Given that we know that autistic individuals were present in the Palaeolithic
past, and able to make a contribution, the question then becomes: why and
how were autistic individuals integrated into past societies?
There are many potential advantages to the inclusion of individuals with
autistic talents. ASCs are associated with elevated abilities in various
domains. These include visual perception (perception of detail, identifying
hidden gures; see Figure 3.6), focus, pitch, smell and taste detection, as
well as social skills such as an unemotional response to crisis and concern
with fairness (see Spikins, Wright, and Hodgson 2016).
Many autistic people have remarkable talents in particular domains. In
studies of over 250 autistic individuals, Meilleur, Jelenic and Mottron (2015)
found that over 60% had some special skills. These ‘savant talents’ occur in
several realms, including computational (listed as ‘easily able to multiply
two numbers in the millions together in head; can tell the elevation of both
the sun and the moon at any time on any date without reference to any
book’), calendrical (‘could tell people what day of the week their birthday
would occur and what day of the week they were born on’), memory (‘a few
years ago, he was bought a book which was read to him; this year we read it
to him again after over a year – if we stopped he would nish the rest of the
Figure 3.6: Example of an embedded gure test. Individuals with ASC have
superior abilities at identifying the shape on the left within that on the
right. Penny Spikins, CC BY-NC 4.0.
154 HIDDEN DEPTHS
sentence quite accurately’) and visuospatial abilities (‘successful in painting
portraits of friends, friends’ children and selling them’) (Howlin et al. 2009).
Strategic social thinking is not always important to being successful. In a
study of 840 Cambridge University students, around 2% scored in an autism
quotient range suggestive of having ASC (Baron-Cohen et al. 2001). As
Baron-Cohen comments,
None of those meeting criteria complained of any current
unhappiness. Indeed, many of them reported that within a Univer-
sity setting their desire not to be sociable, together with their desire
to pursue their narrow or repetitive interests (typically mathemat-
ics and computing) was not considered odd, and was even valued.
(Baron-Cohen et al. 2001: 12)
Our own research has demonstrated the same pattern in students at York
(Spikins, Wright, and Hodgson 2016), as well as how the dierent perception
and skills of autistic individuals are reected in unique forms of art (Spikins,
Scott, and Wright 2017), particular preferences for cherished possessions
(Spikins, Wright, and Scott 2017), and certain attributes of the built environ-
ment (Schoeld et al. 2020). Rather than there being a single human mind,
society is in reality a balance of minds.
Although there may be challenges to the integration of autistic individuals,
it is not dicult to see that some of these abilities could be a real advantage
in realms such as hunting, medicine or technology. Such advantages might
even particularly be important in cases of environmental unpredictabil-
ity, when being able to quickly develop new technologies or exploit new
resources may have been vital to survival. Technological abilities may even
have provided the potential for specialised roles, such as around the pro-
duction of elaborate and highly detailed technologies.
Were autistic individuals integrated into prehistoric societies because of
their talents? An understanding of the signicance of emotional motiva-
tions adds a new perspective to this debate. As we have seen above, when
we make judgements of others, we tend to focus on the emotional motiva-
tions behind their actions – whether they intended to help others or not.
An explanation for the integration of autism should probably look beyond
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 155
simply behaviours and abilities to emotional motivations, and the moti-
vations of autistic individuals to make a contribution to group wellbeing,
albeit perhaps in subtly dierent realms.
Motivations to help others are not aected by ASC per se (that is to say,
individuals with ASC are as likely to be motivated to act for the common
good as are individuals who are neurotypical). Whilst empathy for com-
plex emotions may be impaired in autism, empathy for pain remains intact
(Hadjikhani et al. 2014). Most autistic individuals are highly motivated
to make a contribution, albeit often in particular realms such as law or
medicine or justice (Spikins 2009; Spikins, Wright, and Hodgson 2016). For
this reason, the emergence of group judgements based on genuine emo-
tional motivations (collaborative morality) and around contributions to the
group interests seem likely to have been an important part of the process
whereby autistic individuals became an essential part of the balance of
human societies.
Particular roles for autistic individuals may have been most evident in the
later phases of human evolution (discussed in Part 2), potentially as part of a
process that includes occupation of high latitudes, and larger group sizes in
which specialised roles become more sustainable. However, the inclusion of
autism is discussed here as the primary driver for this process seems not to
be strategic skills that autistic individuals may possess, but rather their shared
human capacity to think about the wellbeing of the group above their own.
There is almost certainly more to understand, and disentangling the mecha-
nisms and reasons behind the inclusion of autism into human societies may
continue well into the future. There are, after all, a number of complexities to
this issue. It would be rather convenient for our understanding if genes sim-
ply mapped onto autism, and yet this quite clearly is not the case. The actual
situation is frustratingly complex. Not only are there over a thousand genes
that show some association with autism but also the relationship between
gene variants and autistic traits is certainly not a simple one. Moreover, there
are complex issues such as epigenetic factors, that is, the potential eects
of environmental conditions on the expression of particular genes. Neither
is the presence of any particular dierence within populations necessarily
any indication that it was selectively advantageous; simply not making a
156 HIDDEN DEPTHS
dierence can be enough, as is often the case with hair or eye colour. As we
shall see throughout this volume, we can construct a speculative explana-
tion for why evolutionary changes took place, but may never entirely under-
stand whether our perfectly plausible explanation is the right one. At best,
we hope we are getting nearer to the truth.
We can be condent that autism is not outside of the human evolutionary
story but is very much part of what makes us human. Certainly, the condi-
tion deserves to be seen in terms of its positive attributes, as well as the
challenges it may impose (Wright, Spikins, and Pearson 2020).
Rethinking our societies of the past as ones in which feelings, motivations
and sensitivities to others were centre stage may help us better understand
the changes taking place.
Further questions
Many questions remain. We have seen through the three chapters in Part 1
of this volume that ecological changes after 2 million years ago, and
opportunities to move into new niches involving greater meat eating
and collaborative hunting, placed new selection pressures on human emo-
tional responses. Increasing interdependence placed selective pressures
on group members to care more deeply about each other, and in long-
term ways.
As a result, we share emotional motivations to share with and care for others
in our group with other highly social and collaborative animals. However,
for all the similarities, our human emotional connections, in particular our
long-term commitments and the importance of trust in our relationships,
are markedly dierent to those of other animals. We can recognise that our
human reliance on emotional commitments has its roots in the complex
social brain of an ape placed under pressure to collaborate in more in-depth
ways. Yet there is also much more to understand about the timing and
mechanisms underlying the signicance of trust and reputation to human
emotional connections.
There is also more to understand about who is cared for, trusted and
included. Here we have focused on the inclusion of dierent minds within
close kin and living groups. But what about the inclusion of strangers or
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 157
people who are dierent or unfamiliar in other ways? To address this ques-
tion, in Chapters 4 and 5 we turn our attention to the evolution of increas-
ing tolerance towards those outside of our familiar living groups. Beyond
the question of other people, however, lies that of other animals, or of even
things with which we develop strong emotional connections. These are top-
ics we turn to in Chapters 6 and 7.
What about competing pressures towards self-interest? It would be foolish
to portray human societies as wholly driven by motivations of generosity
and trust. Rather, there seems to be a balance, both at an individual and
a social level, between pressures towards self-interest or exploitation of
others, and those towards generosity, sharing or compassion. A complex
dynamic exists between our emotional desires to share and care and those
to hold and control (Gilbert 2021). In climates of trust, it may pay to be genu-
inely kind, but there are highly competitive climates in which it pays to be
cunning or exploitative. Both contexts may have existed in a certain equilib-
rium within past societies, or even have been expressed dierently in alter-
native evolutionary pathways in the past. The developmental inuences on
this dynamic, and its implications for the future, are discussed in more detail
in Chapter 5.
There are also many other issues that remain to be explored and for which
this discussion is merely a starting point. Our capacities for emotional com-
mitments themselves bring their own constraints, for example. Close-knit
collaboration brings a cost in terms of tendencies to look inwards rather than
out, and may have restricted the capacity of human groups to make large-
scale connections until at least 300,000 years ago. Dierent evolutionary
branches with dierent types of emotional connections are likely to have
existed, as explored in Part 3. Moreover, emotional commitments have a
darker side. The same loyalties and a willingness to take risks on behalf of
others and to make great sacrices for the sake of the group can also moti-
vate some of the darker elements of human nature, including wars, feuds
and vendettas. There is some evidence that conicts may even have been
important in human dispersal events after 100,000 years ago, for example
(Spikins 2015b).
For all that love and trust are some of our human characteristics that we
most applaud, there is much more that might be said about the nega-
tive side of human loyalties. The drives to defend loved ones and to make
158 HIDDEN DEPTHS
sacrices on the behalf of others play an important role in much of human
war and suering (Spikins 2015a). We may have only scratched the surface
of what might be discussed, discovered or explored.
Wired for trust?
Perhaps we have at least begun a journey towards uncovering evidence
for the signicance of kindness, trust and emotional commitments in our
shared origins. Our understanding of our long evolutionary history of living
in close-knit communities connected by warmth, trust and interdepend-
ence may also cause us to begin to reect on the mismatch between today’s
societies and our evolved make-up. In this light, we may be less surprised
that an education system based on competition, judgement and a focus
on quantifying merit fuels an epidemic of mental ill health amongst the
young. Equally, the causes of high rates of depression in the context of ris-
ing inequality and declining social trust may be easier to explain. In begin-
ning to resolve these issues, and to develop the type of society structures
that promote better emotional connections and support the caring side of
our natures, we might be helped by a more accurate narrative of what made
humans successful as a species than one that emphasises cunning and self-
interest above caring and community.
Conclusions
Our acute sensitivity to the feelings underlying other people’s actions seems
most likely to stem from increasing pressures on early humans to be ever
better at judging who they could safely trust. From here, we began a journey
towards extraordinary attunement to others’ emotions and concerns as to
how we might appear to others.
A focus on changes in our emotional brain, rather than on more strategic
social intelligence, explains how strong bonds relying on mutual generos-
ity fostered survival through challenging environments. It also provides
insights into archaeological questions of changes in teaching and learning,
the integration of dierent minds, and attention to the aesthetics of stone
tools. Rather than intelligence or social understanding, it may have been
changing emotional motivations that allowed more eective collaboration
and made changes in intelligence, social complexity and cultural transmis-
sion possible.
TRUST, EMOTIONAL COMMITMENTS AND REPUTATION 159
Other changes taking place over the last 300,000 years, alongside pressures
to look beyond familiar local allies, added further fuel to changes in social
sensitivity, needs for belonging, and motivations to be likeable, as discussed
in Part 2.
Key points
• Changes in aective empathy and in our emotional attunement to others
may have been a more signicant factor in human social evolution than
developments in social thinking skills. Furthermore, rather than strategic
social astuteness, displaying genuine emotional motivations towards
others and being sensitive to genuine emotions in those around us may
have played a greater role in evolutionary success than we imagine.
• Archaeological evidence suggests that a sensitivity to moral reputa-
tion, the pattern of emotional motivations towards others someone
expresses over time, emerged after 2 million years ago, as seen in a con-
cern for symmetry and aesthetics in stone tool form. Furthermore, later
developments in the signicance of genuine emotional motivations to
group wellbeing, and collaborative morality, may have provided a basis
for the cultural transmission of knowledge and for the inclusion of dier-
ent minds within human populations.
• Our human emotional minds developed through compromises between
strengths and vulnerabilities. Collaboration based on trust and emo-
tional commitments came at the cost of individual sensitivities to what
others think or feel about us.
160 HIDDEN DEPTHS
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Part 2
Tolerance, Sensitivity and
Emotional Vulnerability
In Part 2, we consider the development of human tolerance, or changes in
social approach/avoidance behaviours. We consider how and why we
became capable of extending compassion outwards beyond our close kin
and living group, showing tolerance and generosity towards neighbouring
groups and distant friends, and the implications of this for human social
sensitivity and emotional vulnerability.
We begin in Chapter 4 with the evolutionary basis for our physiological and
hormonal responses to unfamiliar people, before continuing in Chapter 5 to
consider the issue of increasing human friendliness and social sensitivity or
human ‘self-domestication’. In Chapter 6, we consider how new social sen-
sitivities and emotional vulnerabilities changed human relationships with
animals, particularly focusing on our increasingly close relationships
with wolves and their descendants, domestic dogs. In Chapter 7, we con-
sider how and why signicant objects came to play an important emotional
role in our lives. We particularly focus our attention on key changes taking
place relatively late in our evolutionary history, alongside the emergence of
anatomically and cognitively modern humans after 300,000 years ago.
What enables us to form strong relationships beyond our immediate fam-
ily? How did we become friendly towards strangers? What made large-scale
regional connections and the emergence of human communities possible?
And what were the implications of human tolerance for our social relation-
ships and emotional lives?
CHAPTER 4
The Evolutionary Basis for Human
Tolerance – Physiological Responses
Abstract
For most animals, unfamiliar members of other groups present
more of a threat than an opportunity, and are best avoided or even
attacked. In contrast, our attitudes are markedly dierent. There is
no denying that we are capable of being hostile to people we do not
know, particularly if we feel anxious or threatened. However, com-
pared to other animals, we are unusually open to new relationships,
and form strong bonds with individuals outside our family group.
Although we tend to focus on the ‘thinking’ part of our minds, or our
cognitive appraisal of social situations, our physiological responses
and emotional reactions play a central role in how we build and main-
tain relationships. Subtle changes in ‘gut feelings’ can have an impor-
tant inuence on our attitudes to people around us, particularly to
unfamiliar outsiders or people we have not seen for some time.
An understanding of how dierent hormones aect social behaviour
in other species, as well as in humans, provides insights into the type
of changes that led to increasing human ‘friendliness’. Genetic and
(Abstract continued on next page)
How to cite this book chapter:
Spikins, P., 2022. Hidden Depths: the origins of human connection. Pp. 171–219. York:
White Rose University Press. DOI: https://doi.org/10.22599/HiddenDepths.e.
License: CC BY-NC 4.0
172 HIDDEN DEPTHS
anatomical evidence documents subtle changes in neuroendocrine
function in recent human evolution after 300,000 years ago that
appear to have played an important role in increasing tolerance of
unfamiliarity, and abilities to forge new external bonds. Being able
to make external connections, and form new relationships based
on give and take despite lengthy periods apart, seems to have been
important to our success as a species. Friends in distant communities
may often have been important to survival by providing resources
or help that could buer the eects of crises and resource shortfalls.
We nd that it is genuine emotional commitments to distant friends,
rather than strategic alliances, that allow modern hunter-gatherers
to survive in times of crisis.
Changes in emotional dispositions towards being less aggressive
and more tolerant of unfamiliar individuals might seem to be pro-
gress, but we should be cautious in thinking in these terms. Increased
‘friendliness’ is not without its disadvantages. It also brings down-
sides in terms of social sensitivities and emotional vulnerabilities that
inuence much of human behaviour.
(Abstract continued from previous page)
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 173
Introduction
In 2017, researchers working with bonobos at LuiKotale, Democratic Republic
of Congo (DRC), documented an apparently unusual encounter between two
dierent communities of bonobos (Figure 4.1 shows an adult male bonobo,
or pygmy chimpanzee, Pan paniscus). Generally, most animals are distrust-
ful of other groups or are even aggressive towards them. They defend the
boundaries of their resources, or at least take great pains to avoid other com-
munities. This only makes evolutionary sense. After all, other communities
are made up of individuals with whom they will share few, if any, kin relations
and it makes little sense to do anything to benet these potential ‘competi-
tors’. In this case, however, not only were bonobos tolerant of each other’s
company but, more than this, they shared food (Fruth and Hohmann 2018).
Figure 4.1: Male bonobo at Lola ya Bonobo, Democratic Republic of Congo.
Evanmaclean, Public domain, via Wikimedia Commons: https://commons
.wikimedia.org/wiki/File:Male_Bonobo_Lola_ya_Bonobo_2008.jpg.
174 HIDDEN DEPTHS
Bonobos can be aggressive (though only rarely violent) at the boundaries
between communities. However, they can also be tolerant, so this peaceful
interaction was not in itself unusual. On this occasion, however, bonobos
from the eastern community (10 adult females, ve adult males and infants)
joined several members of the western community (12 adult females, three
adult males and infants) (Fruth and Hohmann 2018: 96–97). What happened
next was very much worthy of note. One of the western males, a bonobo
called Camillo, caught a forest antelope (a duiker) and over the next half
an hour responded to appeals from the bonobos from both communities
to share the meat, which was widely shared between them. During this
time, one of the females from the west community and one from the east
groomed each other, and an eastern male and western female mated. Such
behaviours would be unthinkable in chimpanzees, and yet these bonobos
were capable of remarkable tolerance to individuals who were eectively
‘outsiders’. Furthermore, further cases of tolerant interactions emerged over
subsequent research, often taking place where resources were plentiful
(Lucchesi et al. 2020). Peaceful interactions can even occur over several days.
These interactions enabled resources at borders to be exploited, rather than
avoided, and gave opportunities for intercommunity mating to occur. More-
over, peaceful interactions avoid the risks of injury or even death recorded in
intercommunity attacks in chimpanzees.
We might imagine that it pays to defend our community boundaries and be
intolerant towards strangers but, in many cases, collaboration can pay o
more (Spikins et al. 2021). Of course, human collaboration across community
boundaries is much more extensive than that of bonobos. Modern foragers
depend on relationships with other communities for access to resources,
such as raw materials for stone tools, medicines or salt (Pisor and Surbeck
2019), and survival in times of famine often depends on being able to visit
and depend on distant allies (Wiessner 2002). However, bonobos may give
us at least some insight into the earliest beginnings of human tolerance.
Intergroup tolerance in the human evolutionary past
We saw in Chapters 1 and 2 that human social relationships within social
groups in our distant past were highly collaborative, but what were inter-
community relationships like?
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 175
Early humans were certainly highly social, with relationships that revolved
around ready responses to vulnerable group members, collaborative infant
care and sharing of food and other resources. However, these responses
may have focused almost exclusively on kin and living groups. There is
good reason to argue that early humans may have been rather socially insu-
lar and, at best, only very weakly socially connected across large communi-
ties and regions.
It is not uncommon to assume that early human societies must have been
connected within large social networks, much like we might recognise
today. All modern societies, from industrialised societies to those living by
hunting and gathering, are linked by social networks that connect many
people and large regions. We easily assume early human societies resem-
bled some watered-down version of what we know. Moreover, our near-
est relatives live in relatively large connected communities. Fission–fusion
societies, like those of chimpanzees, are made up of communities of 50–150
individuals that come together and separate into smaller parties at dierent
times, and these are often seen as a model for our early ancestors. Inspira-
tion for ideas about early human social groups also comes from multilevel
animal societies that join together seasonally and are made up of individuals
with dierent levels of kin relations. An example of this is seen in elephants,
where individuals are related to key older matriarchs (Wittemyer, Douglas-
Hamilton, and Getz 2005). We tend to expect these kinds of socially com-
plex societies in our early ancestors, because we see ourselves as socially
complex. Furthermore, evidence from changes in cranial shapes through
human origins seemed to support ideas of large early human communities.
Increases in neocortex sizes, associated with increasingly complex social
understanding, have been interpreted as implying large social networks
in the distant past. However, as we have seen in Chapter 3, a relationship
between neocortex size and group size has been called into question. There
are also other explanations for increasing neocortex sizes related to keeping
track of other groups, or to more complex types of within-group relation-
ships such as those associated with trust and emotional commitments.
Evidence from movements of raw materials, the sizes of archaeological
sites, inbreeding deformities and genetics, argue that early human social
groups were surprisingly constrained in size and insular in scope, with
176 HIDDEN DEPTHS
interactions beyond the local group relatively rare. In reality, evidence for
intercommunity interactions does not become widespread until much later
in human evolution, and at least after 300,000 years ago.
One area of evidence is from the movements of raw materials used to make
stone tools. If we look at raw material movements, we see that these largely
come from local areas, often within four kilometres, and most likely reect
exploitation by a local group until at least 1.2 million years ago (Marwick 2003).
Even by 300,000 years ago, evidence for raw material movements beyond
what we might expect to see in local catchments is rare (Layton, O’Hara,
and Bilsborough 2012). There are even apparently unexploited boundaries
between territories seen in the raw material transport networks of archaic
humans in the Near East (Belfer-Cohen and Hovers 2020). These unexploited
areas appear to be symptomatic of a desire to avoid other groups.
The sizes of archaeological sites throughout most of human evolution also
accord with small, constrained groups. Analysis of faunal remains at FLK
Zinj (level 22) at Olduvai dating to around 1.8 million years ago suggest
that a group of around 18–28 individuals occupied the site, for example
(Domínguez-Rodrigo and Cobo-Sánchez 2017). This relatively small number
of individuals matches evidence from footprints at Ileret around 1.5 mil-
lion years ago that suggests a similar size of social-living group (Dingwall
et al. 2013).
Most tellingly, evidence of skeletal material showing deformities related
to inbreeding are seen from as early as 1.5 million years ago, and remain
common throughout most of the Palaeolithic record (Trinkaus 2018). Even
in later phases of human evolution, such as from 1 million to 250,000 years
ago, evidence from skeletal abnormalities is common (Ríos et al. 2019; Ríos
et al. 2015; Trinkaus 2018). Moreover, genetics (Castellano et al. 2014) sup-
ports the notion of high rates of inbreeding in archaic humans, which would
be unlikely to occur where social groups were uid and connected. Genetic
evidence for much greater interactions and mating between groups is lim-
ited to the Upper Palaeolithic (starting around 100,000 years ago in Africa
and 70,000 years ago in the rest of the world) (Sikora et al. 2017).
It seems unlikely that there was no interaction between communities in
early humans. Distributions of similar artefacts suggest that something
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 177
like ‘cultures’ existed in archaic humans after around 300,000 years ago,
at least (Ruebens 2013). However, similar ways of doing things might not
imply community connections on a wider scale – similar behaviours could
be maintained though limited mating network interactions, for example.
It is certainly possible that movements between communities were lim-
ited to those related to mating networks and quite possibly also restricted
to females (Lalueza-Fox et al. 2011). Though we tend to assume that early
hominins lived lives connected within large social networks, probably
based on our own experiences and concepts that they must have been
highly ‘social’ in modern terms, there is no good evidence to support this
idea prior to the emergence of our own species after around 300,000
years ago.
Given that the evidence doesn’t support the notion of large-scale regionally
connected human communities before 300,000 years ago, what were com-
munity relationships like? There is a lot that we do not know. It is not clear if
what we might call a community (a set of individuals who know each other
well) was simply a small group of early humans who foraged together, or
made up of several small groups that foraged together or apart at dier-
ent times. Nonetheless, it is unlikely that group sizes were as large as those
of chimpanzees or bonobos, particularly as an ecological niche involving a
dependence on meat eating will have signicantly constrained population
densities. Certainly, for most of our distant evolutionary past, our ancestors
seem to have been living in social landscapes in which they were ‘thin on
the ground’ (Churchill 2014), making encounters between dierent commu-
nities rare to begin with. There is no reason to imagine aggressive or violent
interactions between dierent communities. Rather, the motivations and
willingness to extend social relationships outside of familiar kin and com-
munity members seem to have still been largely lacking until after around
300,000 years ago. We could perhaps imagine rare intercommunity interac-
tions a little like those recorded in bonobos, which can be aggressive, avoid-
ant or sometimes cooperative.
It is only after 300,000 years ago, beginning in Africa, that a novel open-
ness to new relationships, and the capacities and needs to connect to
an extended social group, appear to have emerged (Dunbar, Gamble,
and Gowlett 2014). From bounded groups with constrained mobility
and limited contacts between each other we see the emergence of uid
178 HIDDEN DEPTHS
connections across large social landscapes. In these new social contexts,
supportive alliances provided a social buer for resource shortfalls and
people maintained connections with a wide number of allies (Coward and
Gamble 2008; d’Errico and Stringer 2011; Foley and Gamble 2009; Spikins
et al. 2021). Raw materials and nished artefacts that might previously have
only come within a predicted home range were now drawn from well out-
side this range, sometimes even over thousands of kilometres, suggesting
both higher levels of mobility and a degree of intergroup exchange (Féblot-
Augustins 2009; Layton, O’Hara, and Bilsborough 2012; Marwick 2003).
The explanation for this transformation in intergroup connectivity remains
enigmatic. Explanations have largely focused on changes in social intel-
ligence and capacities to remember an extended set of group members
(Dunbar, Gamble, and Gowlett 2014; Gamble 2008; Gamble, Gowlett,
and Dunbar 2011), or the ways in which cultural objects might be able to
symbolise identities (Coward 2015; Gamble 1998). However, changes in
emotional dispositions towards unfamiliar individuals may have been play-
ing an important role in these changes. Changes in our biology may also
have played a role in changing how we were able to feel about outsiders.
Here we explore the role of our physiological reactions in our reactions to
unfamiliar individuals, and the ways in which these reactions may have
changed throughout our evolutionary past.
The evolutionary background to human physiological
reactions to unfamiliar people
When we discuss our physiological and emotional reactions to unfamiliar
people, it is usually around the negative elements of other biases against
people who look dierent from ourselves.
It is clear that we have evolved emotional reactions to people who are dier-
ent, which are, at best, unhelpful and, at worst, dangerous. When encounter-
ing strangers, it is sadly all too common to make immediate assumptions
about people. We may judge people by a visible physical disability or be
less trusting of people of dierent skin colour to ourselves, for example. We
even react with greater empathy when viewing someone in pain who has
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 179
the same skin tone as ourselves (Sapolsky 2017). Our immediate intuitive
emotional reactions can be at odds with our principles.
These reactions are certainly unwelcome. However, in an evolutionary
context, they are perhaps not entirely surprising. As we have seen, in most
animals, individuals who are not close relatives or who do not belong to
the same social group are usually best avoided. It is not unusual for typical
responses to unfamiliar individuals to be either fear or aggression. Though
we discussed the highly collaborative, and even tender, nature of wolves
within their group in Chapter 1, fearful aggression to outsiders is typical
(see Figure 4.2). In a moment, they can swap from carer to killer (de Bruin,
Ganswindt, and Roux 2016). Even in multilevel societies of animals that live
in close proximity, of which baboons are perhaps the best example, there
will be close-knit subgroups that do their best to have little to do with the
larger population other than to simply put up with their presence (Städele
Figure 4.2: A wolf showing fearful aggression. Denali National Park and Pre-
serve, CC BY 2.0, via Wikimedia Commons: https://commons.wikimedia
.org/wiki/File:Wolf_Snarl_(5300989527).jpg.
180 HIDDEN DEPTHS
et al. 2015). In animals that live in hierarchically organised kin groups that
separate and rejoin, genuine intergroup collaboration between non-kin is
rare, and there are no emotional bonds with non-relatives in neighbouring
groups. This makes clear sense as neighbouring groups are most likely to
be competitors, presenting a threat to one’s own resources or even the pos-
sibility of violent aggression.
More complex perceptual biases against ‘out-groups’ also exist in primates.
Out-group bias, a tendency to view members of other groups as a whole
as lesser or even dangerous, has been recorded in monkeys, for example.
As with humans, their preconceived biases towards members of out-groups
make it harder for them to associate out-groups with positive things or in-
groups with negative ones. Rhesus macaques shown pairings of members
of their own or a neighbouring group and images of fruit (which they like)
or spiders (which they do not like) stared longest at the ‘discordant’ pairing
of their own group members with spiders, or neighbouring group mem-
bers and fruit. This implies that their own group members were associated
more with nice things (fruit) and other group members with nasty things
(spiders) (Mahajan et al. 2011; Sapolsky 2017: 389). Abilities to identify
with one social group in contrast with another seem to predate the split
between Pan and Homo lineages and so are likely to have existed in our
distant hominin ancestor (Moett 2013). Moreover, chimpanzee ‘pant hoots’
show a distinctive group identity (Crockford et al. 2004) and vocalisation of
early hominins are likely to have been similar. In the far-distant past, there
was good reason to be suspicious of ‘outsiders’ and, despite our modern
friendliness, this suspicion can leave its mark, with people typically using
top-down cognitive appraisal (discussed in Chapter 1) to counteract eects
of visible dierences (Sapolsky 2017). Given this evolutionary context, the
occasional sharing across community boundaries seen in bonobos seems
even more remarkable.
Overcoming these reactions, and being able to eectively collaborate with
other communities in a sustained way that goes beyond the occasional
tolerance seen in bonobos, will have been a major challenge for human
societies. The formation of new collaborative social alliances will have
depended, rstly, on individuals being friendly enough to enable encoun-
ters, rather than being fearful or aggressive, and, secondly, on their being
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 181
open to treating less-familiar individuals a lot like family members, even
though their habits, behaviour or ideas may have seemed foreign (Wiessner
2002: 22). Whilst we typically explain changes in the archaeological record
involving new patterns of mobility, new alliances and greater cultural con-
nectivity after 300,000 years ago in terms of changes in cognitive capacities
or cultural change, changes in emotional motivations may be far more sig-
nicant than we have imagined (Spikins et al. 2021).
What might have happened, and why?
To address these questions, we need to build up a better understanding
of how our neurobiology aects how we relate to other people, and how
evolutionary pressures can create long-term changes in hormonal and emo-
tional reactions.
Neurobiology, emotional responses and social behaviour
We might feel that our physiological responses are rather too basic, or
biological, to have played an important role in something as complex as
changes in human social relationships. However, whilst our physiological
reactions in social situations might not determine what we do, they can
have a signicant inuence. Brain, chemical and hormonal systems which
moderate avoidance (such as fear) can prompt us to keep away from certain
people, whilst others that moderate our approach behaviour (such as caring
responses) make us want to be closer, for example.
Social behaviour in mammals in general is mediated through hormonal and,
in turn, physiological responses to particular social situations. As a result,
one of the main ways in which social behaviour changes between species
is through genetic changes inuencing hormone pathways – that is, how
the neurobiology of our brains inuences us physiologically in any particu-
lar social situation or our ‘gut feelings’ (Narvaez 2014; Narvaez et al. 2013;
Zink and Meyer-Lindenberg 2012). Certain social situations may make us
anxious or afraid, others make us excited, and yet others make us feel calm,
connected and secure. Changes over time in the selective advantages and
disadvantages of dierent social behaviours, including behaviours towards
182 HIDDEN DEPTHS
individuals who are rarely seen or unfamiliar, are strongly inuenced by
‘gut feelings’ under the control of hormonal responses. Of course, how we
behave is about far more than simple biological responses. As discussed
in Chapter 1, our perceptions of a social situation inuence our hormonal
responses and, in turn, our physiological reactions, after which we also have
a top-down control over what we think and how we behave. However, how
we feel can have signicant eects on our behaviour towards other people.
Discussions of physiological and hormonal changes in human evolu-
tion have been limited, with attention particularly focused on changes in
androgens (such as testosterone) and potential eects on reactive aggres-
sion (Wrangham 2014; Wrangham 2018). Reduced aggression doubtless
played an important role in allowing humans to form external social alli-
ances and intergroup collaboration. However, changes in other key emo-
tional dispositions aecting how we interact socially seem likely to have also
played an important role. Rather than any one single response to non-kin
or unfamiliar individuals, a capacity and motivation to forge distant social
alliances seems likely to have been built on several subtle but important
changes in some of the hormonal responses that inuence social behav-
iour (Figure 4.3). Genetic evidence suggests that particular hormones that
play an important role in aecting capacities for tolerance include those
associated with stress reactivity, such as cortisol, those associated with
changes in motivations towards aggression or competition, such as andro-
gens, those associated with reward-seeking behaviour, such as dopamine,
and those associated with social bonding, such as oxytocin, vasopressin and
beta endorphins (Hare 2017; Theofanopoulou, Andirko, and Boeckx 2018;
Theofanopoulou et al. 2017). Each of these hormonal changes appears to
have had an important role to play in setting the emotional scene that ena-
bled humans to develop large-scale collaborative social alliances.
The relationship between genes, hormones and emotional responses, and
how these evolve, is a fast-moving area and the inuence of hormones
on physiology and emotional reactions is complex. In some cases, we see
similar behavioural changes in dierent species from either an increase
or a decrease in the same hormone in the bloodstream, for example (de
Bruin, Ganswindt, and Roux 2016; Trumble, Jaeggi, and Gurven 2015).
This is because responses to hormones are mediated by not only levels in
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 183
Figure 4.3: Changes in emotional dispositions involved in moving from constrained social groupings to large-scale social alli-
ances. Penny Spikins, CC BY-NC 4.0.
184 HIDDEN DEPTHS
the bloodstream but also receptiveness to dierent hormones, and how
hormones react together. This means that we can at best only really talk
about changes in the pathways of particular hormone systems. Moreover,
similar behavioural patterns or changes can take place through diering
hormonal changes. Monogamy in dierent species of lemur is controlled by
subtly dierent hormones, and these are dierent again from those control-
ling monogamy in prairie voles, for example (Grebe et al. 2021). Nonethe-
less, there are some simplications that can at least help us to understand
how evolved hormonal responses may have inuenced human emotions
and behaviours in the past.
What is clear is that subtle changes in emotional reactions, which can often
occur quickly on evolutionary scales, can have far-reaching consequences
on both avoidance behaviours and approach behaviours.
The physiology of changes in avoidance behaviour – how changes in
hormones might make us less competitive or fearful
Often our emotional responses to particular situations tend to push us away
from other people. It goes without saying that we usually avoid people or
social situations if they make us feel aggressive or fearful. In the former case,
behaviour may be inuenced by hormones that control competition and
aggression, such as androgens, and, in the latter case, by hormones that
inuence stress reactivity, such as cortisol.
Competition and aggression – the role of androgens
Readily aggressive reactions might deter any would-be ally we might
encounter. However, there is no doubt that they solved particular adaptive
problems in the evolutionary past – defending resources or our families, for
example. It is no surprise that particular hormones, including androgens
such as testosterone, exist to play an important role in inuencing our gut
feelings towards competition or aggression.
We know that variations in testosterone inuence human social behaviour,
so it only makes sense to conclude that changes in testosterone pathways
over time would also change social behaviours on a larger scale. Tenden-
cies in humans to collaborate or compete with strangers in economic games
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 185
show a relationship with individual variations in testosterone levels, for
example. Those who tend to be most collaborative tend to have lower levels
of testosterone than those who are more likely to adopt a selsh strategy
(Eisenegger et al. 2017; Mehta et al. 2017). This is important, as long-term
collaborations tend to depend on individuals being prepared to be gener-
ous rather than immediately selsh. Those with typically tolerant and col-
laborative personalities are also associated with lower levels of testosterone
than individuals who display traits of narcissism such as extreme selshness
and self-centredness (Pfattheicher 2016). Moreover, in an evolutionary con-
text, reduced levels of testosterone are associated with increased levels of
paternal care in species such as social carnivores (de Bruin, Ganswindt, and
Roux 2016). We might reasonably expect selection pressures on testoster-
one to have been signicant in changes in the balance of competition or
collaboration in human evolution.
Androgens such as testosterone are particularly interesting within an evolu-
tionary context as they have an inuence on physical characteristics which
is potentially identiable in past skeletal material. Androgen hormones
control the development of male reproductive tissues, and bone and body
mass. ‘Extra’ muscle and body size are costly but, where male competition
for mates is highest, these extra energetic costs beyond that which would
be optimal otherwise are worth paying to increase reproductive success
(Muller 2017). Thus, ‘sexual dimorphism’, the dierence in body size between
males and females, gives us important clues as to the level of male competi-
tion driving pressures to be aggressive to other males within and between
groups. Sexual dimorphism shows a relationship with male aggression in
non-human apes. Gorillas, for example, live in groups comprising a single
male and several females. Male gorillas show some of the most extreme
reactions to potentially competing males, reacting aggressively to males
within their group as they reach adolescence and to any adult males that
might approach near to their group. They are also amongst the most highly
sexually dimorphic of primates, with male gorillas larger than females by a
factor of 1.6–1.7 (Plavcan and van Schaik 1997). It pays o for males to invest
in the costly extra eorts of body size, well beyond that which might relate
directly to resource availability, as extra power may make a big dierence in
reproductive success. Male gibbons, in contrast, live in largely monogamous
pair bonds, which means they compete far less with each other, and thus
male and female gibbons are of a similar size.
186 HIDDEN DEPTHS
Sexual dimorphism in ancestral humans gives us some insights into how
human male aggression may have changed through time. On the basis of
fossil evidence, australopithecines show some level of sexual dimorphism,
perhaps not entirely dissimilar to chimpanzees, whilst sexual dimorphism
appears to reduce in early Homo, including the small-bodied Homo naledi
(Garvin et al. 2017). However, making interpretations of fragmentary fossils
is plagued with diculties, not just because only parts of the body are repre-
sented and it is rare to be able to identify males and females separately but
also because dierent specimens tend to be compared across a large geo-
graphical area where environment may be inuencing size (Plavcan 2012;
Plavcan et al. 2005). Most notably, it remains unclear where one ‘species’
ends and another begins in both time and space, making it easy to inter-
pret a high degree of dimorphism between individuals that are actually of
dierent species. It would be unwise to be overly specic about estimates.
Nonetheless, assuming our nearest relatives, chimpanzees, with a sexual
dimorphism ratio of around 1:1.3, are broadly similar to ancestral apes, it
does seem that sexual dimorphism reduces through the hominin lineage.
Modern human males are slightly larger than females on average, by a fac-
tor of around 1.1–1.2, making them more similar in size than estimates for
earlier species (Michael Plavcan 2012). In the broadest terms, it seems that
male–male competition has reduced.
Other evidence for androgen levels in an evolutionary context comes from
2D:4D digit ratios – the dierence in size between our second and fourth n-
gers. 2D:4D digit ratios in modern contexts show a relationship with foetal
testosterone levels (Pearce et al. 2018). The ratios in both early humans and
Neanderthals are higher than those of modern humans, which may suggest
a reduction in testosterone in more recent phases of human evolution (Nel-
son and Shultz 2010; Nelson et al. 2011). Moreover, changes in testosterone
are also implicated in research into key genes that changed with the origins
of modern humans (Theofanopoulou et al. 2017).
Dierences in rates of aggressive conicts and in testosterone pathways
between closely related primate species also provide important insights
into the potential role of testosterone in intergroup relationships.
Chimpanzees are renowned for their tendencies to get into aggressive con-
ict with other groups, in contrast to more common patterns of avoidance
in primates as a whole. Testosterone levels rise from infancy onwards, and
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 187
control the large body size of male chimpanzees compared to females. Tes-
tosterone also has an eect on an individual level, with individual dier-
ences in testosterone levels associated with the rate of aggressive attacks
on others (Anestis 2006). Moreover, on a group level, chimpanzees experi-
ence peaks in testosterone in territorial boundary patrols, which then play
a role in their aggressive attacks (Sobolewski, Brown, and Mitani 2012).
Chimpanzee males at Kibale patrol the limits of their territories, for exam-
ple, forming coalitions to defend the boundaries of their territories and
attacking when they outnumber their opponents, with attacks on individu-
als from neighbouring territories sometimes being fatal (Watts et al. 2006;
Wilson et al. 2014). The most famous and much debated example of chim-
panzee violence even led to an entire chimpanzee group at Gombe being
apparently systematically attacked by a neighbouring group of which they
had previously been a part (Goodall 1986). Aggressors only attack when
they outnumber their opponents, so face little risk to themselves and will
tend to benet in terms of increased access to resources (Mitani, Watts, and
Amsler 2010; Wilson, Wallauer, and Pusey 2004; Wilson et al. 2014). This ter-
ritorial aggression commonly leads to territorial advantages, explaining
why intragroup aggression may have been advantageous in the past (Cro-
foot and Wrangham 2010).
It is tempting to draw a link between chimpanzee aggression, testosterone
and human violence (Wrangham and Peterson 1996). Testosterone also
inuences human aggression, after all. Competitors in team games also
show a surge of testosterone, even when competitions are not physical, and
particularly amongst the winners (Trumble, Jaeggi, and Gurven 2015), sug-
gesting similar positive feelings of solidarity in opposition to the ‘enemy’.
We probably sometimes feel a similar rush of excitement, and antipathy
towards ‘them’ when watching or playing team games, as do chimpanzees
on border patrol. The mechanisms of territorial aggression amongst chim-
panzees have even been compared to particular cases of human intergroup
aggression, such as that of violent youth gangs, for example (Wrangham
and Wilson 2006). It has been suggested that cases of violent ‘raiding’ in
hunter-gatherers reect the same kinds of adaptive advantages to such
behaviours, such as taking over the resources of another group, as those
observed in non-human primates (Pandit et al. 2016).
The apparent similarities may be supercial, however. Cases of human feud-
ing tend to be skewed towards adolescent and young adult males, who are
188 HIDDEN DEPTHS
much more impulsive than adults, given that emotional regulation abilities
are not fully mature until their mid-twenties (Sapolsky 2017). Moreover, it
is clear that hunter-gatherer raiding is motivated by complex beliefs, loy-
alties and commitments (Boehm 2000; Boehm 2011). Perhaps even more
signicantly, hunter-gatherer raiding is set within a context in which there is
also collaboration between groups (Boesch et al. 2008). Rates of intergroup
violence in modern hunter-gatherers tend to be low (Fry and Söderberg
2013), and substantially lower than in chimpanzees (Wrangham, Wilson,
and Muller 2006). Moreover, lethal intergroup aggression is relatively rare in
hunter-gatherers and only seen in certain contexts (Lee 2014), and organ-
ised conict appears to be restricted to late in an evolutionary context
(Kissel and Kim 2018). Our top-down cognitive control usually makes it eas-
ier to rationalise whatever emotions we may feel, and to choose how to act.
The eects of testosterone on social behaviour are far more complex
than they might immediately appear. Testosterone can promote parochial
altruism and generosity on behalf of one’s own group, whilst also promot-
ing out-group aggression, for example (Diekhof, Wittmer, and Reimers
2014). It is probably best thought of not as a hormone controlling aggres-
sion but as one inuencing motivations to compete, which may play out
in complex ways (Sapolsky 2012). Social norms play an important role in
mediating how testosterone aects aggression in chimpanzees as well as
humans, for example. Within dierent chimpanzee groups, there are nota-
ble dierences in attitudes to other groups, particularly being inuenced by
the role of females. There are lower rates of fatal intergroup attacks and far
fewer records of infants being attacked at Taï forest than at Kibale or Gombe,
for example. This seems to be because female chimpanzees at Taï forest are
more likely to be involved in intergroup encounters, which changes the
dynamic of intergroup aggression. Furthermore, Taï forest chimpanzees
tend to spring to the defence of an individual being attacked or taken pris-
oner, even at their own risk (Boesch et al. 2008). Males might feel equally
aggressive but learn that attacks are unlikely to be successful (Fuxjager,
Trainor, and Marler 2016).
Perhaps the most remarkable inuence of social context is that testos-
terone has even been linked to increased generosity in humans, where a
reputation for generosity is considered a mark of status and thus some-
thing worth competing for (Diekhof, Wittmer, and Reimers 2014). Moreover,
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 189
aggression in adulthood is most clearly aected by early trauma rather
than testosterone (Fragkaki, Cima, and Granic 2018), and cultural norms
have a far more signicant eect on aggression than genetics (Shackelford
and Hansen 2015). The structure of social relationships can even inuence
whether other groups feel like competitors. Unlike in modern industrialised
contexts, testosterone levels amongst the Tsimane hunter-gatherers do not
rise in group competitions, as patterns of mobility mean that groups are
made up of a complex mix of kin and non-kin (Trumble et al. 2012) – there
are plenty of close friends and relatives in other groups to moderate any
competitive feelings towards them. There are many social norms and rules
within modern hunter-gatherers that constrain the potential for violence.
The complex and interconnected net of social relationships amongst recent
hunter-gatherers, in which each individual maintains a set of close friend-
ships beyond their own kin, almost certainly plays a role in preventing out-
group biases from developing.
Bonobos provide perhaps the most signicant insight into how the evolu-
tion of diering hormonal pathways can nonetheless inuence behaviour
(discussed in more detail in Chapter 8). Bonobos are just as closely related
to humans as chimpanzees are, and share a common ancestor with them
that lived around 1.7 million years ago. Despite this close evolutionary rela-
tionship, bonobos have androgen responses that are dierent from those of
chimpanzees and contrast quite markedly in their attitudes towards other
groups, as well as in their levels of within-group aggression. In contrast to
the rising levels of androgens seen in chimpanzees, levels of androgens in
bonobos stay at similar levels from infancy to adulthood (Hare, Wobber, and
Wrangham 2012; Wobber et al. 2010; Wobber et al. 2013), with implications
for levels of both internal and external aggressive conict.
Dierences between androgen responses in chimpanzees and bonobos
undoubtedly help explain the capacities for intergroup collaboration in
bonobos, as described at the introduction to this chapter. In contrast with
common chimpanzees, intergroup encounters at the borders of bonobo
groups are far less aggressive. Fruth and Hohmann (2018) estimated that
intergroup encounters occur around one to three times a year amongst
groups at LuiKotale, DRC, and sometimes involve threat displays, although
actual aggression or violence is very rare. However, importantly, neighbour-
ing groups sometimes forage together. Groups come into contact more
190 HIDDEN DEPTHS
often when fruit trees at their shared boundaries are ripe, for example, with
both groups exploiting the same fruit trees (Sakamaki et al. 2018). Most
remarkable of all is the recorded instance of bonobos sharing food at the
borders between groups, described in the introduction to this chapter.
These individuals were clearly comfortable sharing with those from other
communities, something that Fruth and Hohmann commented would be
‘unthinkable’ in chimpanzees (Fruth and Hohmann 2018: 99). It seems likely
that dierences in androgen levels between chimpanzees and bonobos had
a major inuence in the distinctions in intergroup behaviour between the
two species. These might help us understand, therefore, how reduced ten-
dencies towards aggression may also have played a part in changes in soci-
ality in recent human evolution (Wrangham 2014; Wrangham 2018).
Whilst aggressive or competitive responses can certainly lead to avoidance,
the same is also true of fearful or stressed responses to social situations.
Fear, stress reactivity and cortisol
Although changing androgen levels have received the most attention, in
some cases it is reduced stress reactivity, rather than changing motivations
towards aggression or competition, that seem to play the biggest role in
reduced aggression.
Being fearful or stressed in the presence of someone who is dierent or
unfamiliar, and thus being motivated to avoid them, makes evolutionary
sense for most animals. From an evolutionary perspective, there is every
reason to be distrustful, if not overtly aggressive, to outsiders. Firstly, and
most obviously, individuals of one’s own species who are not members of
your own living group are generally not kin, and thus most likely, at the very
least, to be competitors for scarce resources. Other members of one’s own
species may even present a threat to survival if likely to become aggressive
and attack. Furthermore, they may also compete for mating opportunities.
From the perspective of the potential threat that they may present, it is not
too surprising that few species share the potential openness to unfamiliar
members of other groups displayed by humans. Most animals endeavour to
avoid other groups, such as by territorial displays or vocalisations, or resort
to aggressive encounters. It makes sense to take eorts to demarcate the
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 191
limits of where your group lives, such as by vocalisations or threat displays,
and minimise interactions with other groups and warn unfamiliar individuals
not to approach. Howler monkeys (genus Alouatta of the subfamily Alouat-
tinae), for example, demarcate their territory through sound in an attempt
to avoid other groups as much as possible.
For most animals, unfamiliar individuals, or even those they have not seen
for some time, are a source of fear and stress, stimulating the production
of glucocorticoid hormones such as cortisol and what we traditionally refer
to as ‘ight or ght’ responses. A gut feeling to run away is thus a fairly
common response to unusual situations or strangers, in most animals, and
makes such feelings in people who we see as being ‘socially anxious’ all the
more understandable. It even makes sense to try to avoid some of the indi-
viduals within one’s own group. In highly social animals that live in domi-
nance hierarchies we see the production of glucocorticoids in response to
the stresses of managing relationships with higher ranking individuals, who
may be aggressive. It made more evolutionary sense to be stressed and
motivated to avoid the danger of conicts with individuals of higher rank
than not to be stressed by their presence. Low-ranking baboons, for exam-
ple, tend to have such high glucocorticoid levels that being in a constant
state of stress aects their immune function (Archie, Altmann, and Alberts
2012). The kind of stresses they feel are not so dierent from humans today
whose social systems make them fearful and whose immune systems can be
equally aected (Snyder-Mackler 2020).
Evolutionary reductions in stress reactivity can constrain fearful reactions
and so promote approach behaviour. Reduced stress reactivity may be more
important in changes in tolerance in domestic dogs than any changes in
androgens, for example (Miklosi 2014). Cortisol levels are a key element to
tameness in domesticated species, and cortisol levels are three to ve times
lower in ‘tame’ domesticated foxes than in wild ones (Trut, Oskina, and Khar-
lamova 2009), discussed in Chapter 5. Reductions in cortisol are also key
to tolerance in humans. Studies show that human aggression has no sim-
ple relationship to testosterone but also appears to be mediated by stress
reactivity through cortisol (Montoya et al. 2012). Increased tolerance in
humans is thus likely to be a much more complex issue than simply reduc-
tions in androgens. The type of increased friendliness that promotes close
192 HIDDEN DEPTHS
interactions with unfamiliar individuals seems to involve not just reductions
in aggression but also reduced fear through reduced stress reactivity.
There are interesting similarities in reduced stress reactivity between
humans and domesticated animals, particularly dogs. Humans and dogs
are much less stressed by the presence of strangers than is typical for other
species, for example. Securely attached infants and dogs will both prefer
to interact with a stranger than to stay with their owner/caregiver (Feuer-
bacher and Wynne 2017). Dogs and people even often prefer social inter-
action or praise to the immediate basics of survival such as food (Cook
et al. 2016). For dogs, this hypersociality helps free-ranging animals to sur-
vive by approaching people for food. Street dogs in Moscow, for exam-
ple, nd enough resources to survive by forging relationships with new
guardians who them feed them or by begging eectively from passers-by,
including on the subway, showing remarkable tolerance for the potential
stress of unfamiliar humans (Figure 4.4) (Poyarkov, Vereshchagin, and Bogo-
molov 2011). For humans, a capacity and motivation to form new external
friendships is critical to the formation of large-scale networks of connection
(Migliano et al. 2016).
New social relationships can themselves be a means of further reducing
a stress response. The presence of allies lowers the levels of stress in low-
ranking baboons (Silk et al. 2010) and this same process occurs in both
dogs and humans (Heinrichs et al. 2003), not only with their own species
but through human–dog bonds (Buttner 2016). Human stress responses
can even be reduced by the presence of imagined allies, or their proxies in
terms of cherished objects, which can act like compensatory attachments to
repair these rifts. Dogs and other animals (Kurdek 2008), beliefs in spiritual
beings (Lenfesty and Fikes 2017), and even treasured possessions (Bell and
Spikins 2018; Keefer, Landau, and Sullivan 2014; Keefer et al. 2012), can act
like parents or attachment gures, making us feel more secure (discussed in
Chapters 6 and 7).
Making new social allies and friendships is not just about better tolerating
the presence of unfamiliar individuals, however. It depends, however, on
motivations to seek out new people, experiences and situations. We need to
be drawn to friends, unfamiliar people or even animals to form new relation-
ships and even new types of relationships. For this reason, we need to also
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 193
understand why changes in hormones aecting approach behaviour may be
implicated in recent changes in human evolution.
The physiology of changes in approach behaviour – how changes in
hormones might make us more ‘friendly’
Goal seeking exploration and novelty – the inuence of dopamine
Dopamine has received much attention recently as the hormone potentially
involved in addictive behaviours through activating motivation systems.
Dopamine, like serotonin, oxytocin, vasopressin and even testosterone,
is one of the hormones which provide us with pleasurable feelings that
motivate how we behave. It is the neurotransmitter involved in pleasurably
rewarding our motivations to seek things out and pursue goals, and is pro-
duced by the mesolimbic pathway (or ‘reward pathway’) in the brain, which
connects the more ancient midbrain to the forebrain.
Figure 4.4: A Moscow free-roaming dog riding the Metro. A remarkable
change in stress reactivity allows domesticated dogs to tolerate unfamil-
iar humans at close quarters. Here a street dog travelling independently
on the Moscow subway is surrounded by people. Adam Baker, CC BY 2.0
via Wikimedia Commons: https://en.wikipedia.org/wiki/Street_dogs_in
_Moscow#/media/File:Street_Dog_Riding_the_Subway.jpg.
194 HIDDEN DEPTHS
In common with other animals, dopamine motivates us to seek out food
or sex. However, dopamine release has also been co-opted through human
evolution to motivate our behaviours in a wide variety of complex social
contexts (Sapolsky 2017). As we have seen in Chapters 1 and 2, dopamine
plays a key role in the ‘buzz’ we get from helping others (Rilling 2011). Dopa-
mine rewards encourage us to collaborate with others or give to charity, as
well as to punish cheats or feel good about the downfall of someone we dis-
like (Takahashi et al. 2009). We even experience dopamine-related pleasure
as an aesthetic response, such as to particularly moving music (Salimpoor et
al. 2013), or even to cultural objects such as sports cars (Knutson et al. 2007).
Changes in dopamine are also likely to have been key to seeking out new
relationships. As outlined in Part 1, changes in emotional responses are likely
to have been important in transformations in social relationships occurring
after 2 million years ago. There are suggestions that these changes may
have included changes in dopamine as a result of an increase in available
fats through increased meat eating (DeLouize et al. 2017). Nonetheless, this
hormone may have been most signicant in more recent periods. Dopa-
mine inuences whether novelty and risk are perceived as pleasurable, and
so plays a particularly signicant role in adolescent novelty seeking and risk-
taking. Changes in dopamine with sexual maturity play a key role in motivat-
ing mobility to maintain mating networks in social animals, for example. As
Sapolsky explains, the lowered dopamine levels of subadult male baboons
prompt them to seek similar ‘thrills’ in the novelty of neighbouring groups,
as individuals in their own groups seem dull in comparison (Sapolsky 2017).
As a whole, adolescents feel less dopamine-based pleasures for small
rewards and much greater dopamine-based responses to larger rewards
than do adults (Vaidya et al. 2013) – sensible options are less rewarding and,
with self-control not yet fully mature, risk-taking and impulsivity become
ever more likely (Padmanabhan and Luna 2014; Steinberg 2008).
Dopamine can play an important role in directing dierent behaviour
between males and females. It is changes in dopamine and reward-seeking
behaviour that allow individuals to overcome their reluctance to associate
with members of other groups in the context of mating. At sub-adulthood,
males or females (depending which sex moves, usually only one) experience
novelty and risk as pleasurable, largely through changes in dopamine and
actively seek out members of other groups. We can see this process in male
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 195
baboons. As a male baboon matures, their feel-good dopamine reward
through novelty reduces, and they begin to seek higher and higher levels of
novelty to feel any kind of thrill. When neighbouring groups meet, the males
will threaten each other and then the groups will retreat, but the adolescent
males may linger far longer, appreciating the novelty of the other group.
Slowly, the individual will spend more time with the other group, until even-
tually they transfer groups (Sapolsky 2017: 162). Changing hormones at
adolescence have changed how males feel about other groups.
In chimpanzees, it is the females who repeat this same process of being
drawn to the novelty and excitement of neighbouring groups. Female chim-
panzees typically move when they reach adolescence and sexual maturity.
The tolerance shown to males and females from other groups also varies.
Whilst chimpanzee males and infants are typically the focus of aggressive
and often fatal encounters, females, particularly those in oestrus, are almost
never attacked. Even once they have moved to another group, female
chimpanzees may still form relationships with individuals in other groups.
Around 10% of infants in the Taï forest result from matings with males who
are not members of their own group (Boesch et al. 2008).
Generalisations about the structure of social communities may not neces-
sarily describe how all members behave when we take age and sex into
account. Whilst we may imagine a landscape of entirely bounded groups
in chimpanzees, and a certain level of fearfulness of potential aggressive
encounters, this characterisation holds less clearly for subadult females.
Female chimpanzees are far more free to move between groups than males,
and it is the movement of females that ensures sustainable mating networks
(Boesch et al. 2008). The ‘female perspective’ on mobility is an important
one. The intensity of lethal intergroup aggression, and the extent of sup-
port for victims of attacks and for ‘prisoners’, varies with the role of females
in intergroup interactions. Where females are more involved in intergroup
interactions, as at the Taï forest, there is substantially less violence (Boesch
et al. 2008). The role of females also seems to be key to the lack of intergroup
conict and the potential for intergroup collaboration in bonobos (Furuichi
2011). Female primates are no stranger to defensiveness and even violence
when protecting their young (Hrdy 2011). However, a transition to tolerance
for out-groups seems far less of a leap from a female perspective than it
196 HIDDEN DEPTHS
appears from a male one. Females may stay within their own group most of
the time, but at least sometimes venturing to associate with other groups is
more appealing than scary.
Dopamine aects modern human males and females in similar ways.
Whilst culture and conscious choices play an important inuence,
modern human adolescents are also disproportionately driven to experi-
ence increased drives to risk-taking and novelty by hormonal inuences
on dopaminergic activity in the brain in ways not dissimilar to other
mammals. The same hormones also aect their ability to evaluate risk
(Kelley, Schochet, and Landry 2004). Amongst the Baka, for example, ado-
lescent males travel great distances to learn new skills from acknowledged
specialists, typically motivated by seeking to impress potential partners. In
doing so, they play an important role in transmitting knowledge and forg-
ing social networks.
How dopamine changes at adolescence aected mobility in pre-modern
humans remains a matter for debate. Evidence for movements of males
and females in australopithecines on the basis of strontium isotope analysis
shows the smaller individuals having a non-local signature. Given that the
smaller individuals are likely to be female, this suggests primarily females
making movements out of the local area (Copeland et al. 2011). The genetic
relationships between a Neanderthal group buried under a rockfall at El
Sidrón in northern Spain also potentially suggests that Neanderthals were
patrilocal, as the group consisted of three brothers with unrelated females
and their infants (Lalueza-Fox et al. 2011). It is tempting to suggest that,
prior to modern humans, with their distinctive pattern of high mobility and
movements by both males and females, archaic and earlier humans showed
a chimpanzee-like gender-based mobility pattern, though more evidence
would be needed to conrm that this was the case. It is nonetheless notable
that archaic and earlier humans show high levels of inbreeding (Trinkaus
2018), suggesting that drives to seek out unfamiliar others, even in relation
to mating networks, were somewhat constrained. In contrast, the emer-
gence of modern humans is associated with entirely new levels of mobility,
and genetic diversity (Apicella et al. 2012; Templeton 2015). Both a greater
propensity to explore and a lack of constraint on gender would have had an
important inuence on levels of interbreeding.
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 197
Changes in the eects of dopamine may be one of the mechanisms by
which selection pressures created increased tameness/friendliness dur-
ing the most recent phase of human evolution after around 300,000 years
ago (Cagan and Blass 2016; Theofanopoulou et al. 2017). Whilst we might
imagine that reduced aggression is key to such processes (through reduced
androgens), friendliness depends on connection and openness to novel
experience. It is, thus, dopamine which encourages approach behaviour,
and dopamine receptor D4 gene (DRD4) is associated with gazing towards
humans in domestic dogs for example (Hori et al. 2013). Dopamine has also
been associated with maternal bonding (Atzil 2017) and abilities to develop
social networks (Pearce et al. 2017).
Increases in the presence of particular dopamine variants may even be impli-
cated in human dispersals after 100,000 years ago. One particular dopamine
receptor variant, the 7R (seven repeats or the long allele version) form of
dopamine DRD4, is particularly interesting. The 7R variant is associated with
relative unresponsiveness to dopamine (i.e. greater thrills are needed for the
same response) and is associated with a host of behaviours, including extra-
version, exploratory behaviour, novelty seeking, promiscuity, less sensitive
parenting, impulsivity and susceptibility to ADHD (Bakermans-Kranenburg
and van Ijzendoorn 2006; Chen et al. 1999; Garcia et al. 2010). Polymor-
phisms in DRD4 predate the dispersal of modern humans out of Africa after
60,000 years ago (Chang et al. 1996; Chen et al. 1999; Ding et al. 2002; Kidd,
Pakstis, and Yun 2014). Modern populations that undertake long migrations
tend to have greater proportions than more sedentary populations of indi-
viduals with long alleles of the DRD4 gene, associated with novelty seeking
and hyperactivity (Chen et al. 1999). Moreover, populations farthest from
the African origin have the highest rates of the 7R variant associated with
impulsivity and novelty seeking. The Ticuna, Surul and Karitiana, occupy-
ing the Amazon Basin, have a roughly 70% incidence of 7R variant; the Gui-
hiba and Quechua of northern South America have an incidence of around
55%; and the Maya in Central America have an incidence of around 40%,
with lower incidences in more northern populations of the Americas, for
example (Ding et al. 2002; Matthews and Butler 2011; Sapolsky 2017). Indi-
viduals more prone to novelty seeking may be more likely to nd the pros-
pect of new regions alluring, and the familiar as boring, as well as being
less prone to stress in novel situations. How they behave will, of course, be
198 HIDDEN DEPTHS
inuenced by culture, and what is novelty seeking and risk-taking in one
society might seem tame in another. Equally, as with many subtle hormonal
distinctions, dierences bring both advantages and disadvantages. There
will be contexts in which it may be benecial to be more prone to novelty
seeking, and in others where it is less so. Risk-taking, and a desire for novelty,
might be benecial overall in yielding rewards in terms of accessing new
resources, or might be a disadvantage due to an increased mortality risk.
Genetic variation in DRD4 alleles has other interesting characteristics. It
is also one of the best examples of gene–culture interaction, in that the
behaviours associated with dopamine-related genes depend on cultural
context. Long (2R or 7R) allele variants bring an elevated sensitivity to the
experience of parenting. That is, securely attached individuals with 7R vari-
ants will be more generous than average, whilst the insecurely attached will
be less so, for example (Bakermans-Kranenburg and van Ijzendoorn 2011).
Moreover, individuals with the long allele variants seem to be more sensi-
tive to cultural inuences (Tompson et al. 2018). Such individuals tend to be
more individualistic in individualistic cultures and more interdependent in
collectivistic ones, to such an extent that the dierences between the two
cultures on these characteristics disappear if individuals with the long allele
variant are excluded from analysis (Kitayama et al. 2014). Like many adaptive
variations, there is no simple ‘better form’, as being more sensitive to one’s
social context is rather a double-edged sword – such sensitivity also brings
a vulnerability to insecure or unsupportive environments.
As well as dopamine, as we have seen in Chapter 1, other hormones also
play a key role in maintaining strong relationships. Oxytocin, often called
the ‘cuddle hormone’, is the most famous, but vasopressin, beta endorphins
and serotonin also play important roles in making our closet relationships
feel comforting and rewarding.
Bonding hormones
As we have seen in Chapter 1, bonding hormones play an important role
in social bonding, motivating generosity, care for the vulnerable and altru-
ism within close-knit social groups. Selection on neuroendocrine pathways,
including oxytocin and serotonin, are associated with dierences in social
behaviour between chimpanzees and bonobos, for example (Kovalaskas,
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 199
Rilling, and Lindo 2020). Changes in oxytocin and beta endorphins are likely
to have played a role in the expansion of compassion towards a broader set
of group members that we saw occurring between 2 and 1.5 million years
ago (Feldman 2017; Gordon et al. 2010). Oxytocin, in particular, is involved
in social touch, grooming, and behaviours that facilitate strong emotional
bonds, motivate generosity and altruism, and reduce stress (Snowdon 2011).
The role of oxytocin in intergroup collaboration is rather more complicated.
Given a long evolutionary history as a motivator of nurturance behaviour in
mammalian mothers, oxytocin provokes both nurturance of the young and
their defence, including defensive aggression (Snowdon 2011; Ziegler
and Crockford 2017). Oxytocin thus has a role in promoting defence from
outsiders. As we have seen in Chapter 1, oxytocin is known as the ‘tend and
defend’ hormone (Ziegler and Crockford 2017). In this way, oxytocin can
thus play a role in increasing intergroup conict, through promoting emo-
tional commitments, and aggression and conict where external groups
are seen as a threat (De Dreu et al. 2011; Ne’eman et al. 2016). Competitive
aggression may be motivated by testosterone; however, oxytocin is impli-
cated in what we might better see as emotional commitments and motiva-
tions to defend vulnerable young. Defending justice by punishing cheats
has a similar reward system in humans (de Quervain et al. 2004). The inu-
ence of oxytocin is further complicated by apparent dierences between
human males and females, with some evidence that females are more likely
to often ‘tend and befriend’, seeking emotional support from others at times
of stress, than necessarily defend from a perceived attack (Taylor et al. 2000).
Dierences between individuals in particular oxytocin receptor genes pro-
vide interesting insights. Certain gene variants (G allele of a common variant
(rs53576)) confer advantages in interpreting social cues, empathising with
others and building trust. Individuals with these genes are in many ways
more prosocial (Dannlowski et al. 2016). They are better able to read emo-
tions from facial expressions (Dannlowski et al. 2016) and to build stronger
and more trusting and supportive relationships as adults than those with
the A allele (Chen et al. 2011). However, such potential advantages come at
a price. In situations in which there is a lack of parental warmth, individu-
als with the socially sensitive G allele are more susceptible to depression
(McQuaid et al. 2013), and other mental health conditions (Dannlowski
et al. 2016), and they suer more in conditions of social isolation (McQuaid
200 HIDDEN DEPTHS
et al. 2015). Diering empathy between individuals mirrors, in some ways,
the eects that increasing prosociality and tolerance have had on increas-
ingly social sensitive humans in the later stages of human evolution.
Bonding hormones such as oxytocin may play a key role in the formation
of those important few friendships with high levels of trust, in which we
know people are there for us when we need them, rather than forming
extensive social networks (Pearce et al. 2017). Once avoidance or stress
responses, which might trigger us to see unfamiliar individuals as outsiders,
are overcome (see above), humans’ empathy towards strangers triggers
oxytocin release and subsequent generosity (Barraza and Zak 2009). Lon-
gitudinal studies following humans from infancy to adulthood describe
oxytocin involvement in the transfer of attachment from parents to friends
and romantic partners (Feldman et al. 2013). Close friendships are thus a
particular form of bond, extending from maternal attachment and roman-
tic attachments (Feldman et al. 2013). Oxytocin increases following contact
with friends (Feldman 2017). Changes in oxytocin late in human evolution
(Theofanopoulou, Andirko, and Boeckx 2018) may thus relate to new capaci-
ties to form close friendships. In the case of domesticated dogs, for example,
changes in oxytocin-related bonding have brought them new abilities to
form close bonds with their owners (Kis et al. 2014; Kis et al. 2017). Oxytocin
and similar bonding hormones also play a role in how networks are main-
tained, through motivations towards mutual generosity, feelings of grati-
tude, and desires to maintain contact and improve the wellbeing of distant
friends (Algoe and Way 2014; vanOyen Witvliet et al. 2018).
Other related hormone changes are also signicant, and attention has
also particularly been drawn to changes in serotonin pathways. Seroto-
nin is another hormone inuencing our mood and social behaviour that
is likely to have been subject to selection pressures in human evolution. It
plays a role in inuencing attachment styles (Gillath 2008) and propensi-
ties to obey or challenge social rules (Gelfand 2011; Mrazeket al. 2013). A
particular polymorphism of serotonin inuences social sensitivity and, with
it, susceptibility to supportive or unsupportive environments within mod-
ern populations. Alleles within the 5-HTT linked polymorphic region confer
greater plasticity to the eects of childhood mistreatment. One form is asso-
ciated with greater empathetic perspective-taking in supportive environ-
ments but also brings disadvantage in terms of a higher risk of traits such as
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 201
depression or impulsivity in unsupportive or traumatic childhood environ-
ments (Flasbeck et al. 2019). As a result, those of us inheriting a tendency to
be more socially sensitive, under the inuence of genetic dierences inu-
encing the hormone serotonin, are both more severely aected by negative
social experiences and more buoyed up by positive ones (Assary et al. 2020).
The former have even been dubbed ‘orchids’ – so empathetic and highly
tuned to the emotional and social tone of their environment that they are
more deeply aected than others by cruelty, neglect or isolation, particu-
larly in childhood, whilst the latter dubbed ‘dandelions’ are more resilient
and better able to thrive regardless of their environment (Boyce 2016).
Orchids do particularly well in supportive social environments, understand-
ing others more fully and forming close social relationships, and particularly
beneting from the condence and emotional wellbeing that such environ-
ments foster. However, they are more likely to do badly where such support
is lacking. There seems to be an evolutionary balance between these alter-
native strategies – one (orchids) that is particularly successful in supportive
environments and another (dandelions) more resilient to harsh social con-
text. This polymorphism even inuences our propensity to be prone to feel-
ing nostalgic (Luo 2019) and, so, our tendencies to derive comfort from past
(rather than present) experiences. Variations in serotonin pathways within
populations provide a good example of how increasing social sensitivity is
not simply an advantage but also sometimes a disadvantage depending
on context.
Other subtle genetic dierences within populations that inuence hormo-
nal responses have also been identied. One particular arginine-vasopressin
allele, EVPR1A (rs 1117 4811), which is found at high frequency in modern
humans, is linked to prosocial phenotypes while the ancestral allele is asso-
ciated with antisocial phenotypes, for example (Theofanopoulou, Andirko,
and Boeckx 2018).
As more genetic studies are undertaken, we are likely to have an even better
understanding of the inuence of these genetic changes on neurochemical
responses. However, it is always wise to be somewhat cautious not to over-
interpret genetic evidence. On the level of dierences within populations
we need to be particularly careful. There are dierences within populations
that are strongly inuenced by inherited genetics, such as autism or dys-
lexia, that should not be ignored and which challenge us to be better at
202 HIDDEN DEPTHS
understanding dierent but equal perceptions of the world (discussed in
Chapter 3). However, we should not imagine that people with particular ser-
otonin polymorphisms or particular oxytocin receptor genes or any other
genetic dierence aecting hormonal mechanisms could or should be iden-
tied as dierent. Such inuences are only felt at population level and not at
the individual, and are far less signicant than culture, background or indi-
vidual choice in how people behave. To begin to separate people according
to these subtle genetic dierences would be folly.
Where an understanding of the evolution and function of hormones and
their inuence on behaviour is useful is around the ‘big picture’ patterns of
changes in human evolution. Understanding the role and function of these
key hormones, and how changes may have aected human ‘gut feelings’ to
unfamiliar or non-kin others, gives us some insights into how selection pres-
sures acting on these hormone systems may have played a role in evolution-
ary transformations in human social behaviour.
Selective pressures on human tolerance
What mechanisms drove changes in human tolerance? It has often been
assumed that changes seen in those human neuroendocrine responses
that aect approach–avoidance behaviours must be a result of social selec-
tion pressures. These have variously been argued to derive from selection
for cooperative and non-aggressive mates or allies (Hare 2017), or even
active social control of aggressive males and reactive aggression (Wrang-
ham 2018; Wrangham 2019a; Wrangham 2019b). The more important it
was to demonstrate one’s collaborative motivations, the less popular more
aggressive individuals might be, with group level controls perhaps exerting
a strong inuence moderating bullying, dominating or aggressive behav-
iour (Boehm 2012; Boehm 2015). There are also other potential mechanisms.
As explained in Chapter 3, collaborative morality also places selective pres-
sures on group-focused motivations and behaviours, in turn promoting
more tolerant and inclusive traits.
Social inuences on tolerance inevitably played some role in human evo-
lutionary changes. However, there are other explanations. Amongst non-
human apes and other primates, the ecological context plays a key role
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 203
in determining those situations in which friendly encounters between
dierent groups are advantageous rather than disadvantageous. Bono-
bos, for example, are more friendly at the boundaries between communi-
ties where there are abundant resources and opportunities to learn about
how to exploit unfamiliar environments (Lucchesi et al. 2020). Bonobos have
similar characteristics of physiological changes in approach behaviours as
do humans and, in their case, the sharing of food boundaries rather than
aggressive confrontation is an advantage (as we have seen at the start of this
chapter). As human societies became more dependent on a wide variety of
resources, not only food and water but also int, raw materials for tools and
other resources used for even medicines, competition over resources may
have become more disadvantageous (Pisor and Surbeck 2019). Moreover,
increasingly challenging environments, caused by increasing aridication,
alongside increasingly unpredictable resources, may have placed greater
pressures on collaboration in certain regions of Africa after around 300,000
years ago at the emergence of our species (Spikins et al. 2021). Whilst much
debated, the question of the relative roles of internal social selection pres-
sures and external ecological inuences remains unresolved.
It remains an open question whether internal social selection processes,
which may have taken many dierent forms, ecological pressures acting
on particularly human resource requirements, or indeed a combination
of many factors, pushed certain hominins towards increasing friendliness,
whilst other species may have taken a dierent pathway (as discussed in
Chapters 8 and 9).
Conclusions
We would be wrong to see the suspicion of unfamiliar individuals, which is
so typical of most ‘wild’ animals, as equally natural to humans. Life in highly
collaborative societies, discussed in Part 1, is likely to have set in place pres-
sures for humans to simply be less aggressive than their distant ancestors.
However, the changes in emotional dispositions that paved the way for the
formation of recognisably human tolerance to unfamiliar individuals seem
to have occurred relatively late in our evolutionary history. These changes
were probably more complex than simply related to reduced aggres-
sion, and seem to have involved dierent hormonal pathways inuencing
204 HIDDEN DEPTHS
aggression, fear, excitement and anticipation and bonding. Though internal
social processes may have played a part in these transformations, ecological
factors may also have had an important role.
Changes in genetics and anatomy in the recent evolutionary past, after
300,000 years ago, argue that being more tolerant was increasingly
important during this period. Changes in neuroendocrine pathways are
likely to have played a key role in shaping both changes in approach and
avoidance behaviours. Such changes bring both advantages and disad-
vantages, however. Whilst tolerance brought with it capacities to approach
unfamiliar individuals and things, increased openness to new experiences,
and increased social sensitivity, it also brought emotional vulnerabilities
(discussed in Chapter 5).
Key points
• Most animals tend to avoid unfamiliar individuals belonging to other kin
groups, or are even aggressive towards them.
• Neuroendocrine responses inuence systems of hormones that govern
avoidance or approach behaviours, such as through feelings of safety
and security, feelings of threat or desires to explore.
• Evolved physiological changes, such as reduced stress responses
towards unfamiliar individuals, can be advantageous in situations where
intergroup collaboration may be an advantage.
• Evolutionary changes aecting reductions in avoidance behaviours
(such as through changes in androgens or stress reactivity) and enhance-
ments of approach behaviours (such as changes in dopamine or bond-
ing hormones) are implicated in changes in tolerance in recent human
evolution.
• An increasing external tolerance or approachability in human responses
towards unfamiliar individuals brings both advantages and disadvan-
tages, including not only the possibilities of formation of large-scale
social networks but also social sensitivities and emotional vulnerabilities.
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 205
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CHAPTER 5
The Evolutionary Basis for Human
Tolerance: human ‘self-domestication’?
Abstract
The idea that humans could be ‘self-domesticated’ is certainly rather
strange and unlikely-sounding, perhaps not entirely out of keeping
with something we might expect to nd in a science ction novel.
However, there is good evidence that changes in emotional tenden-
cies and capacities in recent human evolution (after 300,000 years
ago) followed some similar pathways to those seen in domesticated
species. Furthermore, these changes are not necessarily limited to
animals that have been deliberately domesticated by humans, with
some of these developments also seen in bonobos, which, along-
side chimpanzees, are our nearest living relatives. Though questions
and debates remain about why and how these changes might have
occurred, genetic and anatomical evidence, alongside changes in
the archaeological record, support the notion that changes similar
to domestication were occurring in humans.
The concept that the evolution of human emotional tendencies and
capacities may have followed similar changes in increasing tolerance
(Abstract continued on next page)
How to cite this book chapter:
Spikins, P., 2022. Hidden Depths: the origins of human connection. Pp. 221–254. York:
White Rose University Press. DOI: https://doi.org/10.22599/HiddenDepths.f.
License: CC BY-NC 4.0
222 HIDDEN DEPTHS
seen in domestic animals is a challenging one. Rather than elevat-
ing modern humans above other animals, it would imply that some
of the most crucial adaptations in our recent evolutionary past are
shared with many other species. Moreover, with many traits chang-
ing under simple and single selection pressures, it contradicts any
notion that human capacities are necessarily ‘adaptive’. Many of our
social traits may simply be emerging alongside key changes but have
no adaptive role, or even be a disadvantage.
There are also added complexities. Increasing tolerance associated
with self-domestication has largely been viewed as an entirely pro-
gressive development in the recent human past, opening up pos-
sibilities for more tolerant and connected communities to emerge
and, in turn, enabling communities to become more resilient to
resource shortfalls. However, there are costs and disadvantages
to these changes in emotions, particularly at the individual level,
which are rarely considered. Heightened sensitivities to social and
cultural context, and hypersociability, bring increased vulnerabilities
to disrupted emotional wellbeing in unsupportive contexts, as well
as the types of challenges we associate with a certain eagerness to
please. The emotional challenges that self-domestication brought
may have been part of processes leading to compensatory mecha-
nisms, such as attachment uidity and tendencies to be driven to
nd additional emotional support and comfort outside of human
relationships (discussed in Chapters 6 and 7).
(Abstract continued from previous page)
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 223
Introduction
Since 1959, and continuing today, a fascinating experiment into the domes-
tication of a wild species has been taking place in Novosibirsk in Siberia.
This experiment provided remarkable evidence for how quickly behav-
ioural physiological and external changes can take place under selection for
friendliness or tameness.
Dmitry Belyayev and, later, Lyudmila Trut directed experiments with the
breeding of hundreds of farmed silver foxes (a subtype of red fox, Vulpes
vulpes, with black fur). In each generation, the foxes that were most toler-
ant of humans were bred with each other to create increasingly ‘tame’ foxes
(see Figure 5.1). Changes happened remarkably quickly. Foxes were notably
more tame after only two generations, with oppy ears and changes in pig-
mentation occurring after 10 generations. Farmed foxes could be ‘tamed’
after about 30–35 generations of selection and eventually became keen to
Figure 5.1: A Russian domesticated red fox with ‘Georgian white’ fur colour
(2015). Keyfedewa at English Wikipedia, CC BY 3.0 via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Georgian_white_Russian
_domesticated_Red_Fox.jpg.
224 HIDDEN DEPTHS
interact with humans. This experiment remains the most remarkable exam-
ple of rapid domestication of a wild animal yet recorded.
‘Tame’ foxes, in comparison to non-domesticated foxes, showed a range of
cognitive, behavioural and physical dierences from their wild counterparts.
They showed a reduced fear response to new situations, and an increased
friendliness to humans, from as young as one month old. They approached
people and licked their faces, whining and barking to attract human attention.
They were also better able to ‘read’ human expressions and were as success-
ful as puppies at nding hidden food on the basis of human clues (Belyaev,
Plyusnina, and Trut 1985; Belyaev and Trut 1975; Hare et al. 2005; Trut, Oskina,
and Kharlamova 2009). As well as physiological changes, in many cases foxes
showed a change in appearance, with changed pigmentation (black and
white patterning), shorter tails, more upward ‘waggy’ tails, oppy ears,
and underbite and overbite (dental abnormalities). They also showed a
shortening and widening of the skull and changes in oestrus (some females
began mating twice a year and so producing more litters). Neuroendocrine
changes included a down-regulation of hypothalamic–pituitary–adrenal
(HPA) axis activity and reduced basal and stress reactive cortisol levels (stress
reactivity and fear response), higher serotonin levels, and changes in dopa-
mine and norepinephrine (Belyaev, Plyusnina, and Trut 1985; Belyaev and
Trut 1975; Hare et al. 2005; Trut, Oskina, and Kharlamova 2009). Though foxes
had only been selected on the basis of their lack of aggression, these other
traits seem to come as part of the wider package of ‘domestication’.
These foxes, in eect, became more like dogs in both physical appearance
and in temperament, being eager to please and enjoying human aection,
and many were sold as pets.
Though no experiments have ever quite matched those with silver
foxes, there are other cases of similar changes under pressures for tame-
ness, reduced aggression or tolerance in other animals. Rats selected for
tameness show similar changes in face shape, for example (Singh et al. 2017).
Even less forcefully directed selection pressures can create similar changes.
A long-term study for over 14 years of free-living wild house mice in Swit-
zerland exposed to human handling as pups also demonstrated changes
associated with domestication, including a reduction in snout length and
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 225
change in pigmentation (Geiger, Sánchez-Villagra, and Lindholm 2018).
What was particularly interesting about this latter study is that, in this case,
mice were not being actively selected for aggression, simply being passively
exposed to greater interaction with humans. They were always able to come
and go as they wished, through holes in the barn used for the experiment.
In a sense, then, perhaps these mice had ‘self-domesticated’ in response to a
new adaptive niche in which food and freedom from predators was readily
available as long as they could tolerate handling from humans. The same
types of changes in snout length and braincase size, and in levels of sex-
ual dimorphism, are even seen between rural and urban red foxes (Vulpes
vulpes) in the UK, which match the changes occurring under ‘domestication
syndrome’ (Parsons et al. 2020).
Perhaps most remarkably of all, similar genetic changes and changes in
anatomy have been seen in recent human evolution. Similar morphologi-
cal changes seen in the human face shape to those in ‘domesticated’ spe-
cies in recent human evolution, and similarities in neurophysiological
changes, make a strong argument for our having followed a similar evo-
lutionary pathway, leading to our increasing friendliness and tolerance to
unfamiliar individuals.
Human self-domestication?
The parallels between changes seen in Siberian silver foxes, other domes-
ticated species such as dogs, and those in recent human evolution are
perhaps surprising.
Similar genetic changes are implicated in both modern humans and domes-
tic dogs, as well as in other domesticated species. These include signals of
positive selection in specic genes including RNPC3, FAM172A, PLAC8L1,
GRIK3 and BRA (Theofanopoulou et al. 2017). These key pathways inuence
neural crest cells (Wilkins, Wrangham, and Tecumseh Fitch 2014) and, in
turn, hormone systems, as well as other aspects of cognition, biology and
behaviour. Similarities across species seem to be explained by high-level
genetic controls of many elements of responses – in eect, single changes
may cascade down. In this way, cascading sets of changes inuencing ‘gut
feelings’ towards unfamiliar individuals explain an association between
226 HIDDEN DEPTHS
increasing friendliness or tameness with anatomical changes, particularly to
the shape of the face (Singh et al. 2017).
Adaptive changes under pressures for increased tolerance are also reected
in human anatomical and physical changes. Anatomical changes, such as
in face shape in humans occurring between 300,000 to 30,000 years ago,
follow a similar trajectory to changes seen in other animals under domes-
tication (Hare 2017; Hare, Wobber, and Wrangham 2012; Theofanopoulou,
Gastaldon, and O’Rourke 2017; Theofanopoulou et al. 2017). Over the last
300,000 years, humans have experienced a attening of their faces (Cieri et
al. 2014; Godinho, Spikins, and O’Higgins 2018), reduction in cranial volume
(Hare 2017), and reduced tooth size (Brace, Rosenberg, and Hunt 1987), as
well as changes to the shape of the brain and the jaw (Theofanopoulou et al.
2017), which is seen in domesticated dogs; see Figure 5.2. The same changes
are also seen in other ‘domesticated animals’ (such as sheep and cows), wild
animals articially selected for tameness such as rats (Singh et al. 2017) or
ferrets (Hernádi et al. 2012) or ‘self-domesticated’ animals such as bonobos
(Hare, Wobber, and Wrangham 2012). These include: changes in pigmen-
tation; shorter face/muzzles; smaller teeth; smaller cranial capacities (and
brain size reduction); a more juvenile-like appearance and temperament;
reduction of sexual dimorphism and more frequent oestrous cycles, and so
longer period of fertility, as well as (specic to species) oppy and reduced
ears and curlier tails.
Many people argue that recent changes in physiology aecting avoidance
behaviours and approach behaviours, as outlined above, warrant describ-
ing humans as a ‘self-domesticated’ species. Whether we should really term
humans ‘self-domesticated’ is a matter of debate, and there are certainly
a number of unknowns around what self-domestication really is or how it
comes about.
It is not clear if the idea of humans becoming self-domesticated fully ts the
changes taking place in recent human evolution. Some argue that these
recent physiological changes are also in some way distinctive from those
seen in ‘domesticated’ species, such as by aecting development in dierent
ways. As a theory it is, after all, somewhat dicult to test (Sanchez-Vallagra
2019). As we shall see in Chapter 8, for archaic and modern humans, the
generalisations close-knit and approachable may be more useful terms than
an oversimplication into ‘wild’ and ‘tame’.
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 227
Figure 5.2: Salient craniofacial dierences between modern humans (top
left) and Neanderthals (top right), and between dogs (bottom left) and
wolves (bottom right). The pattern of recent cranio-facial changes in mod-
ern humans (above) shows a remarkable similarity to that of domesticated
animals such as dogs (below). CC BY 4.0, reproduced from: Theofanopou-
lou C, Gastaldon S, O’Rourke T, Samuels BD, Martins PT, et al. (2018), Self-
Domestication in Homo sapiens: Insights from Comparative Genomics, PLoS
One. Available at: https://journals.plos.org/plosone/article?id=10.1371
/journal.pone.0185306.
228 HIDDEN DEPTHS
The process of domestication is often far more complex than it might
appear. There may be many traits that change under single selection pres-
sures, and many dierent selection pressures that might lead to similar
changes (as discussed in Chapter 4). Reduced antisocial reactions to unfa-
miliar social situations can come about not only through the reduction in
aggression but through a reduction in stress reactivity. The relationships that
dogs develop with humans (discussed in more detail in Chapter 7) involve
new types of approach behaviour that are equally, if not more, important
than any reductions in aggression. There have been suggestions that it may
not have been selection against aggression that was key to the Siberian
experiment, as many of the adaptations shown by the Siberian silver foxes
may have occurred prior to the experiment as a result of adaptations to the
stresses of the farm environment in previous generations (Lord et al. 2020).
Whatever we decide to call changes in tolerance in human evolution, there
is also debate over why and how this may have occurred (discussed in
Chapter 4). Dierent theories have been put forward, ranging from selec-
tion for increased prosociality and friendliness (Hare 2017) to selection for
reduced reactive aggression (Wrangham 2019), to the eects of secure
food resources on female choice for less aggressive males (Gleeson and
Kushnick 2018), to the pressures of ecological changes aecting the adap-
tive advantage of sharing between communities (Spikins et al. 2021). Oth-
ers argue that alternative selection pressures, such as for self-control, were
responsible (Shilton et al. 2020). We often tend to assume that it was unique
internal social pressures that drove human self-domestication. However, it
is equally possible that external ecological drivers played a key role (Spikins
et al. 2021).
Despite the limitations of the term ‘self-domestication’, and that we are as
yet in the early days of understanding how and why these changes take
place, there are certainly important parallels in the ways in which hormones,
physiology and anatomy change in human evolution that demonstrate
similar changes to those seen in domesticated or self-domesticated species
(Hare 2017; Wrangham 2014; Wrangham 2019). Many of the changes we
see as humans become more externally socially tolerant share similarities
with how other animals also react to selection pressures to become more
friendly, less aggressive or more ‘tame’.
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 229
Implications
The implications of humans following a similar pathway of changes in physi-
ology, hormone systems and behaviours to domesticated species (such as
dogs) and self-domesticated species (such as bonobos) are profound.
The rate of change seen in experimental and even semi-wild conditions
demonstrates that marked changes in emotional capacities and tendencies,
or perhaps temperament, could have occurred relatively rapidly in evolu-
tionary terms. Extensive changes in behaviour under pressures to reduce
aggression or increase approachability can result from even quite subtle
changes in physiology, which can take place even over only a few genera-
tions. We should not necessarily expect changes in approach or avoidance
behaviours to occur over the timescales of hundreds of thousands of years
that we often associate with signicant evolutionary changes.
The scope of changes occurring under a single selection pressure, from
reduced aggression, approachability and eagerness to please to facial
shape and pigmentation, also tells us something important. It is easy to
assume that human traits evolved for a reason, and yet this diversity of
traits associated with self-domestication demonstrate the folly of assuming
adaptedness of human traits. It can be easy to assume that, if we can create
a plausible story about how some aspect of our bodies or brains might have
been adaptive, this should explain its existence. However, many, if not most,
human traits probably emerged through the complex associations between
dierent genes that came along for the ride when others were selected for,
and might even have been a disadvantage.
Complex social emotions are one particular example of our tendency to
assume adaptedness. Complex social emotions, created through an inter-
play of both aective and cognitive empathy (discussed in Chapter 1), are
important motivators of our behaviour. We feel social emotions, such as
guilt or gratitude, because of our understanding of what other people think
or feel about us, and our understanding of what is expected of us or them.
These social emotions tend to motivate us to behave in prosocial ways that
help others. We can make a plausible argument for why gratitude may have
been selected for, starting with reciprocal relationships, which we see in
230 HIDDEN DEPTHS
non-human primates, and becoming a basis for strong alliances based on
give and take (Allen 2018). Certainly, gratitude plays an important function
in our positive social relationships, encouraging support and mutual collab-
oration (Smith et al. 2017; Wood et al. 2010). Certain genes even predispose
people to a greater likelihood of experiencing gratitude (vanOyen Witvliet
et al. 2018). However, despite the advantages and link to particular genes,
gratitude might equally simply be a side eect of changes in aective and
cognitive empathy occurring for other reasons. Other complex social emo-
tions, such as shame, do not even seem to serve even a useful function, with
feelings of shame strongly associated with depression and motivating an
unhelpful withdrawal from relationships (Gilbert 2000).
We prefer an ordered world, and a meaning to most elements of our exist-
ence, but nature does not always provide it.
Perhaps most signicantly, the idea that many key changes in our social ten-
dencies could align us with other animals, rather than elevating us above
them, challenges our notion of human exceptionalism. We do not feel
entirely comfortable with the notion that we might feel ‘friendly’ to stran-
gers or eager to please others in ways not unlike those of pet dogs. How-
ever, appreciating that we are perhaps more animal than we think might be
important for many reasons, not least of all in recognising that we are part of
nature, and vulnerable to ecological changes as much as any other species.
The advantages of increasing tolerance
There is good reason to think that changes associated with increasing toler-
ance played a key role in the success and expansion of modern humans as
a species.
Increasing tolerance has been argued to be associated with important
developments such as reduced aggression and greater egalitarianism
through levelling mechanisms (Wrangham 2019), increased collaboration
(Hare 2017), more sophisticated language and communication (Thomas
and Kirby 2018), enhanced self-awareness and creativity (Zwir et al. 2021),
enhanced emotional expressivity in faces (Godinho et al. 2018), and even
changes in body cognition, allowing more sophisticated tool use (Bruner
and Gleeson 2019). Certainly, a new tolerance and capacity for external
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 231
social focus to human communities would have allowed connections to
form between living groups and kin groups. At the same time, a reduction in
stress reactivity accompanied by increased novelty seeking will have moti-
vated the maintenance of distant social connections, reduced inbreeding,
and created regional connected communities. Such connected commu-
nities, in turn, reduce the risks imposed by local resource shortfalls (Pisor
and Surbeck 2019; Spikins et al. 2021). Forming external allies provides the
possibility of creating large-scale resilient networks that buer eects of
ecological changes and, moreover, allow knowledge and culture to spread.
Moreover, a certain playfulness, or attraction to novelty, may also at least
partly explain extensive dispersions, and attraction towards new ways of
doing things (discussed in Chapter 4).
Archaeological evidence supports a picture of many of these important
changes in social behaviour appearing initially in Africa after 300,000 years
ago and leading to a remarkable global expansion of ‘modern humans’.
From around 300,000 years ago, certain populations of humans started to
show changes in the crania, such as reductions in brow ridges and other
changes in facial form that we associate with increasing tolerance (as dis-
cussed in Chapter 6) (Bergström 2021; Stringer and Galway-Witham 2017).
At Jebel Irhoud in Morocco, for example, some of the human fossils dat-
ing to around 315,000 years ago have more modern human-like features,
including a atter face and much reduced brow ridge (Hublin et al. 2017;
Richter et al. 2017). Across Africa, we see a diverse range of archaic and more
modern-like characteristics in various fossils (Bräuer 2015). Crania from Omo
1 and Herto in Ethiopia with a more modern cranial shape appear around
195,000 and 165,000 years ago, respectively. These more modern forms
are contemporary with a diverse set of other types of human, from robust
descendants of Homo erectus to small-brained Homo naledi, following dier-
ent evolutionary pathways (discussed in Part 3).
A combination of increasingly challenging and increasingly fragmented
environments seems to have driven particular selection pressures on both
physical and social characteristics. In this period, we also see material evi-
dence for increased mobility in certain regions of Africa in the form of raw
materials travelling further away from the source until their eventual dis-
card. These extended distances of raw material transport may reect more
232 HIDDEN DEPTHS
external-focusing social behaviours in human populations, and a greater
ease with which longer-distance movements across many territories could
take place. At around 300,000 years ago in the Olorgesailie basin in South
Kenya, at a time of increasingly variable environments and periods of
resource stress (Potts et al. 2018), we see raw material being procured from
a wider area. From typically local raw material distance transfers of around
ve kilometres, we see new movements of obsidian of around 25 to 50
kilometres, and up to 95 kilometres in certain cases, implying interactions
with neighbouring groups (Brooks et al. 2018). The distances over which
materials are transported also increase in other regions. Middle Stone Age
populations in the Kalahari imported preferred silcrete raw material from up
to 295 kilometres, particularly during drier periods (Nash et al. 2013; Nash
et al. 2016). Certain populations seem to be more mobile, and better able to
negotiate moving through areas usually occupied by particular groups, or
even exchanges with them.
Ecological factors play at least some role in these changes. Many environ-
ments become more challenging for survival in Africa after half a million
years ago. Increasingly, aridication is evident in East Africa, and is associated
with extinctions in the South Kenya Rift between 500,000 and 400,000 years
ago (Owen et al. 2018). Alternating periods of arid and wetter conditions
aected southern African environments, placing pressures on human pop-
ulations in dry periods and prompting dispersions along wetter corridors
(Kutzbach et al. 2020). Across the whole continent, highly diverse ecological
contexts, the expansion and contraction of the Sahara, basin structure and
variable topography provide a unique environment (Foley 2018) in which
distinct subdivided populations seem to have emerged and periodically
connected (Bergström 2021; Galway‐Witham, Cole, and Stringer 2019; Scerri
et al. 2018).
Increasingly harsh environments, environmental unpredictability and land-
scape diversity may have been signicant factors in changing the selective
advantages and disadvantages of dispositions towards unfamiliar individu-
als. Unpredictable environments will have led to an increased frequency
of shortfalls in resources. Diverse and fragmented landscapes reduce the
synchronicity of shortfalls, however, as dierent groups would not all have
experienced shortfalls at the same time (Campenni, Cronk, and Aktipis
2017). Moreover, optimum conditions for peaceful interaction between
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 233
groups occur in the most fragmented landscapes, as these are the contexts
in which populations can control their interaction and maintain their own
integrity (Rutherford et al. 2014). For human societies, pressures to share will
have been exacerbated by a reliance on a far greater variety of resources –
not only food and water but also int raw materials for making tools, other
resources such as salt (Pisor and Surbeck 2017) or even medicines (Spikins
et al. 2021). Initially, changes in disposition towards unfamiliar individuals
may simply have meant that interactions at the boundaries between liv-
ing groups become more friendly and collaborative in nature, encouraging
shared resource exploitation in these particular locations. Through time,
the nature of intergroup collaboration could have become more sophisti-
cated and, in turn, more eective in reducing the impact of unpredictable
resources and frequent shortfalls (discussed in Spikins et al. 2021).
Increasing mobility and interaction is also evident from genetic evidence.
For example, excursions of populations out of Africa into Europe led to
interbreeding with early Neanderthals around 200,000 to 400,000 years
ago (Posth et al. 2016). A modern human jawbone found at Misliya cave in
Israel suggests modern humans were in the Near East by 180,000 years ago
(Hershkovitz et al. 2018), whilst tooth remains in China also place modern
humans there at least 100,000 years ago (Liu, Wu, and Xing 2016). Similarly,
archaeological evidence places humans in Saudi Arabia at Jebel Faya as
early as 125,000 years ago (Armitage et al. 2011; deMenocal and Stringer
2016; Groucutt et al. 2018). There is also evidence of greater movements
within Africa, with climate changes also seeming to play a role in these pat-
terns of migration (Lamb et al. 2018; Petraglia, Breeze, and Groucutt 2019;
Rito et al. 2019; Timmermann and Friedrich 2016).
It is only following these anatomical and behavioural changes that we
see the successful expansion of modern humans out of Africa, eventually
replacing (with some low levels of interbreeding) previous archaic species
and expanding into previously unoccupied regions, such as the far northern
latitudes, the Americas and Australia (Bergström et al. 2021). Although there
may be many questions about the timing and mechanisms of this ‘global
diaspora’, it seems highly plausible that changes in social tolerance played
a key role in these developments. Whilst there may also have been changes
in cognition or culture during this period, changes in social tolerance (as
discussed in Chapter 4) created connected communities, providing genetic
234 HIDDEN DEPTHS
diversity, resilience to resource shortfalls and the cultural transmission of
innovations (Spikins 2021).
All of these developments t a clear picture of human ‘progress’. Even the
way we phrase changes, in terms of archaic or modern species (with no
commonly accepted alternatives available), imposes a clear concept of pro-
gression toward ourselves as the better or ‘modern’ form. However, there is
another side to the changes taking place. Increasing tolerance also brings
emotional vulnerabilities. In making us more connected to the feelings of
everyone around us, and not just our close kin, developments in potential
connectedness and social awareness also bring increased vulnerability to
feelings of insecurity when connections are not available, anxieties over
what others think or feel about us, and even the predisposition towards
other debilitating emotional disorders.
The constraints and disadvantages of increasing tolerance
As we have seen in Chapter 4, evolutionary changes aecting key hor-
monal responses and associated with increased social tolerance in recent
human evolution aect many dierent realms of social behaviour. Changes
in hormones aecting aggressive responses and stress reactivity increase
tendencies and capacities to approach unfamiliar others, whilst those in
exploratory and bonding hormones inuence an increased social and emo-
tional sensitivity.
Rather than a simple success story, increasing tolerance is best seen as
more of a complex set of compromises, advantages, disadvantages and
constraints. Some attention has been paid to this other side of the story in
a focus on how new types of aggression, associated with labelling of out-
groups as subhuman, might be associated with human self-domestication
(Hare and Woods 2021). However, this alternative form of aggression remains
dicult to identify in archaeological evidence, and emotional commitments
to defend one’s group against perceived others predate this transition (dis-
cussed in Chapter 3). Perhaps even more important is another disadvantage
brought by tolerance, in this case potentially overlooked owing to our dis-
comfort with vulnerability (discussed in the introduction to this volume).
This comes from emotional vulnerabilities we continue to suer today.
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 235
Alongside the potentials that increased tolerance brings come pitfalls at
both an individual and a community level, as well as a need for individual
and cultural responses to emotional vulnerabilities (see Figure 5.3).
Most obviously, direct eects of recent genetic changes inuence human
vulnerability to specic emotional and cognitive disorders. Recent changes
Figure 5.3: Representation of new styles of community connection devel-
oping in recent human evolution through neuroendocrine changes,
leading to greater external tolerance and approachability. Penny Spikins,
CC BY-NC 4.0.
236 HIDDEN DEPTHS
in neurological plasticity are associated with the emergence of a greater
number of deleterious alleles, bringing heightened susceptibility to the
appearance of abnormalities, particularly those aecting cognition (Castel-
lano et al. 2014; Cruz, Vilà, and Webster 2008; Theofanopoulou et al. 2017).
Most eects on our emotional vulnerability are more subtle, however.
Social understanding and being socially sensitive is, perhaps, best seen as
being more of a double-edged sword than a straightforward strength. In
domesticated and self-domesticated species, we see better abilities to pick
up human social cues, but at the same time as an increased eagerness for
human social contact and a vulnerability to insecure attachments, for exam-
ple. Like these other species, our neurological sensitivity to our social sur-
roundings has come at the price of a greater vulnerability (Sherwood and
Gómez-Robles 2017). Both dogs and humans are susceptible to attachment
insecurity, for example (Bradshaw 2017). Without socially supportive envi-
ronments and positive social interactions, both also suer emotional dis-
tress and susceptibility to disorder. Heightened social sensitivities allow for
sensitivity to social and cultural context in development, but also bring with
them other eects.
This is even more evident when we consider contrasts in social sensitiv-
ity within human populations. Individuals found to have enhanced social
capacities show a greater vulnerability to the eects of harsh social contexts
(Assary et al. 2020). These include those associated with enhanced oxy-
tocin-related sensitivities to facial expressions (Marsh 2019) and serotonin-
related sensitivities to social experience (Flasbeck et al. 2019), which elevate
abilities to make friends easily and thrive in socially supportive contexts.
In unsupportive contexts, these socially adept individuals suer tenden-
cies to depression and other emotional disorders (Dannlowski et al. 2016;
McQuaid et al. 2013), as well as sensitivity to feelings of isolation (McQuaid
et al. 2015). Taking an adaptive pathway towards increasing social sensitivity
brings with it a notable cost, in terms of emotional wellbeing, which is felt in
contexts where there is any lack of caring social support.
Because of recent changes in human evolution, we are all remarkably sensi-
tive to the eects of loneliness, which has an even more pronounced eect
on health than obvious physical onslaughts such as smoking (Holt-Lunstad
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 237
et al. 2015; Leigh-Hunt et al. 2017). Compared with other apes, we also have
a far greater desire, and need, for closeness and touch (Bzdok and Dunbar
2020; Hewlett et al. 2019). People who are simply playing an online game,
cyberball, even feel acute pain similar to that of physical pain when they
are excluded from playing with other contributors (Hartgerink et al. 2015).
We are uniquely sensitive to signs of judgements from others, criticisms, or
potential loss of status, and are all too prone to remodel these criticisms
on ourselves, leading to tendencies towards anxiety or depression (Gilbert
et al. 2009). Our drive to connect and belong, which forged large-scale
human communities, brought with it heavy individual costs when our
longed-for connections are missing.
In order to thrive emotionally we need extensive emotional connections,
not only in childhood but throughout our lives. Without socially supportive
environments through childhood, or what is perhaps best known as a lov-
ing home, we nd it hard to handle our complex emotions. Around 25% of
people in modern industrialised societies have some level of attachment
disorder, or emotional insecurity though insecure attachment to their car-
egivers as infants or which develops in adulthood (Mikulincer and Shaver
2017), for example, with far-reaching eects. Insecure attachments aect
not only trust and the quality of close emotional relationships but also many
other aspects of our lives, such as our physiological reactions to challeng-
ing situations, our abilities to handle dicult feelings, our risks of suering
emotional disorders, our condence to explore and even our physical health
(Table 5.1).
This eect of emotional insecurity is not limited to childhood; it can also
create changes in emotional wellbeing in adults. Even ideological indica-
tors that our environment is not supportive can aect our sense of social
and emotional security. Ideals of individualistic competition drive us to self-
criticism and damaging levels of perfectionism, for example (Curran and Hill
2017). Subtle cultural eects are even so pervasive that a fascinating, if rather
worrying, example of how sensitive we are to social context, even as adults,
comes from research into how studying traditional self-interested econom-
ics aects social relationships. Economics is a discipline that, traditionally,
particularly focused on the concept of individual rational self-interest and
thus students felt surrounded by rationally self-interested (rather than
238 HIDDEN DEPTHS
PHYSIOLOGICAL
Attachment insecurity leads to:
– increased distress at stressful events (Mikulincer and Florian 1998)
– greater physiological reaction to betrayal (Lawler-Row et al. 2006)
– increased cortisol levels (Jaremka et al. 2013)
– increased feelings of pain (Davies et al. 2009)
– impairments in immune system function (Gouin and MacNeil 2019;
Jaremka et al. 2013)
COGNITIVE/EMOTIONAL
Attachment insecurity leads to:
– reduced abilities to regulate emotions (Mikulincer and Shaver 2018)
– reduced ability to suppress negative thoughts (Gillath et al. 2005)
– greater propensity to depression and anxiety (Bejinaru 2017)
– reduced condence to explore new situations and new relationships
(Feeney and Van Vleet 2010)
– reduced creative problem-solving (Mikulincer, Shaver, and Rom 2011)
– increased reaction of amygdala to threats (Norman et al. 2015)
– impaired prefrontal cortex development (Insel and Winslow 2011;
Strathearn 2018)
SOCIAL DYNAMICS
Attachment insecurity leads to:
– reduced compassionate helping (Gillath, Shaver, and Mikulincer 2005;
Mikulincer et al. 2005)
– a negative (vs positive) slant on others motivations (Mikulincer and Shaver
2005)
– increased negative orientation towards out-groups (Mikulincer and Shaver
2001; Saleem et al. 2015)
– greater conict and violence in romantic relationships (Mikulincer and
Shaver 2005)
– reduced tendencies to forgive oences or betrayal (Lawler-Row et al. 2006)
Table 5.1: Eects of attachment insecurity on human physiology, cognition,
emotions and social dynamics.
caring) social actors in their imagined worlds during their degree. Marwell
and Ames (1981), Frank et al. (1993), and more recently Bauman and Rose
(2011), explored these eects in now-famous studies. They found that,
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 239
as they progressed through their degree, undergraduates in economics
became less able to share and develop relationships based on trust, and
less willing to contribute to the public good. Eectively, they changed their
internal emotional schema towards social relationships, arguably becom-
ing better prepared to survive in their perception of a self-oriented social
environment around them. Despite thinking of ourselves to be individual
independent beings, resilient to the opinions or attitudes of others around
us, we are surprisingly vulnerable to the emotional tone of the social con-
text we have experienced in the past and the one we live in today.
It is not dicult to see that human social sensitivities aect not only
individuals but also communities. Individually, we are acutely emotion-
ally vulnerable to our social context. As infants and children, we may ben-
et from a supportive context and become generous, trusting, condent
to explore and emotionally resilient as adults. Alternatively, we may be
aected by a lack of support and become less generous, less trusting and
lacking in condence, with eects even felt at the level of our feelings, or
pain, or the functioning of our immune system. As adults, the same sensi-
tivities continue to operate, leading us to thrive in supportive social groups
and communities where there are supportive ideologies, and suer in com-
petitive or socially harsh groups, communities or ideologies. However, a
larger-cultural-scale supportive community will tend to be populated with
individuals who are more generous and collaborative, creating greater resil-
ience through give and take, whilst, in unsupportive contexts, there will be
a less collaborative ethic.
Compensatory mechanisms
Societies that have coped stably for thousands of years with the challenges
posed by our emotional vulnerability show a number of adaptations that
support both individual and collective wellbeing. Modern hunting and
gathering societies, in particular, provide a good example. In such socie-
ties, people are equally concerned as in industrialised contexts about what
others think or feel about them (Wiessner 2014) and, whilst attachment
disorders may be rarer, they nonetheless still exist (Briggs 1970). However,
over many thousands of years, such communities have learnt ways of pro-
viding emotional support that can counteract many of our vulnerabilities.
240 HIDDEN DEPTHS
For one thing, the emotional investment in infants is distributed amongst
several dierent individuals who willingly give time and eort towards
care of infants and children, providing many alternative sources of emo-
tional support, and making shortfalls in emotionally supportive care much
less likely. Children form strong bonds with unrelated adults, as well as
with relatives (Hewlett and Lamb 2005; Hewlett, Lamb, and Leyendecker
2000). Amongst some groups, such as the Bayaka, infants will spend as
long in the arms of their fathers as in their mothers’, and are often cared
for by many other family members and non-kin (Hewlett, Lamb, and Ley-
endecker 2000). Moreover, learning is situated in an emotional context in
which adults care about children’s emotional wellbeing and understanding
of the world (Boyette and Hewlett 2017). Furthermore, at a cultural scale,
great eorts are made to promote harmony and constrain dominance
(Boehm 2012), with constant communication within social groups, as well as
great eorts to support social connections between groups through regu-
lar aggregations, rituals and celebrations (McDonald and Veth 2012). Rules
and rituals also exist to prevent the escalation of conicts. Many would link
modern psychological distress with a loss of the sharing and caring ethic of
hunter-gatherer communities (Gilbert 2021). These communities, so often
seen as somehow ‘primitive’, have learnt what works to make societies and
individuals resilient over thousands of years of living with our evolved emo-
tional vulnerabilities.
We may think of our emotional vulnerabilities, and the risks they bring of
pain and suering, as weaknesses, but they exist through being essential to
a shared communal strength and resilience against hard times. Connected
communities would probably not have been possible without emotional
vulnerabilities driving a need to connect to others and to belong to a larger
community, the desires to feel valued, or concerns about reputation. As we
explore in Chapters 8 and 9, other pathways with equally viable, albeit less
connected, ways of living also existed. However, modern human ancestors
built on motivations to care for others (discussed in Chapters 1 and 2) with
recent changes in tolerance, adding further drives for new types of emo-
tional connection. Because we need to belong and make wide social con-
nections, we seek out others beyond our local group when, without such
needs, we might be content with our local kin. Because we are driven to
explore, we like to meet new and dierent peoples. Because we are sen-
sitive to others’ judgements, we seek to full social roles and be accepted
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 241
and respected. Because we are prone to loneliness, we seek extensive net-
works of friends and allies. Even expressions of vulnerability themselves
promote trust and social connection (Evans and Krueger 2009; Strohkorb
Sebo, Traeger, and Jung 2018). Furthermore, changes in human face shapes
over the last 100,000 years allow much greater expression of emotions that
make us vulnerable, such as insecurity or sympathy (Godinho, Spikins and
O’Higgins 2018).
Our emotional vulnerabilities may also explain some of our uniquely human
compensatory mechanisms. Whilst our desires to feel socially connected,
and our need for aection, make us vulnerable to any lack of social sup-
port, they seem to have also provoked new ways of generating a feeling of
belonging and connection to compensate for this vulnerability.
Human abilities to compensate for our emotional vulnerabilities through
new types of support go well beyond those seen in other animals. Animal
orphans, such as infant chimpanzees, sometimes form attachments to new
parents, and in some cases these parents may even be a dierent species.
However, for humans, compensatory attachments are widespread and go
well beyond any replacement parent. We form much more common and
in-depth attachments to non-human animals, which often play an impor-
tant role in our lives. Yet, compensatory attachments that bolster our emo-
tional wellbeing go well beyond other living beings and extend to spiritual
beings, or even objects. As children, we often have imaginary friends or per-
sonied objects (such as a favourite teddy bear), with their own characters
and personalities, for example, with personied objects being found across
many dierent cultures. As adults, it is common to believe in an invisible
and intangible god (Mackendrick 2012). Like imaginary companions, beliefs
in spiritual beings often come to the fore at times of loneliness or anxiety,
and comforting spiritual beings can have a signicant impact on emotional
wellbeing (Lenfesty and Fikes 2017). Compensatory attachments of other
kinds, such as to pets or objects, come to the fore in adults in response to
social isolation or loneliness (Niemyjska and Drat-Ruszczak 2013). Perhaps
rather surprisingly, many people nd greater comfort from their pets than
their relatives (Serpell 2016), or feel closer to their god than to their friends
(Niemyjska and Drat-Ruszczak 2013). Pets (Kurdek 2008) and objects (Bell
and Spikins 2018b; Keefer and Landau 2014; Keefer et al. 2012) can act as
psychological attachment gures. Much like a parent, they function in the
242 HIDDEN DEPTHS
same way to bolster condence and wellbeing at times of insecurity. These
compensatory attachments are extraordinarily rare, if even ever recorded,
in other animals.
Whilst most sources of emotional support remain invisible archaeologi-
cally, some forms of compensatory attachments leave certain visible traces
of their existence. In the following chapters, we will explore two examples.
Firstly, in Chapter 6, we will consider a new attachment to cherished per-
sonal possessions, appearing after 100,000 years ago. Secondly, in Chapter 7,
we will consider a new attachment to particular social animals, dogs, which
appeared in the same period.
Like the Siberian foxes described at the start of this chapter, subtle changes
in emotional responses in our ancestors had far-reaching eects on our lives.
Conclusions
Despite sounding rather bizarre as a concept, the notion that human emo-
tional capacities and tendencies have travelled along similar pathways to
those of domesticated species, such as dogs, or ‘self-domesticated’ species,
such as bonobos, is broadly supported by genetic and anatomical evidence.
Quite why and how this transformation took place remains hotly debated.
There are plausible arguments around internal causes, such as general
pressures towards increasing friendliness throughout human evolution or
selection pressures against reactive aggression, as well as external eects of
ecological changes. Whatever the precise explanation, that these changes
bring us closer to other animals, rather than further away, is signicant to
our perspectives of ‘progress’ in human origins.
Transformations in tolerance and friendliness appear to have been key
to enabling connected communities to emerge, providing resilience to
resource shortfalls through sharing beyond local groups. In turn, connected
communities allow for innovations to spread rapidly, enabling quick tech-
nological responses to environmental changes. However, increasing social
tolerance also brings disadvantages. Social sensitivity during develop-
ment leaves individuals vulnerable to unsupportive contexts, with insecure
THE EVOLUTIONARY BASIS FOR HUMAN TOLERANCE 243
attachments having widespread eects in many dierent realms of social
life and even physical health. Compensatory cultural mechanisms to facili-
tate social connections such as aggregations may have partly mitigated
these vulnerabilities. Equally, compensatory attachments to non-human
beings may also have provided emotional comfort at times of stress.
Key points
• Human emotional capacities and tendencies towards increased tolerance
in recent human evolution (after 300,000 years ago) seem to have fol-
lowed similar paths to those seen in domesticated and self-domesticated
species, with similar changes seen in anatomical and genetic evidence.
• The reasons for human ‘self-domestication’, as well as precisely what this
means, remain debated.
• At the scale of human communities, increases in social tolerance pro-
vide the basis for the emergence of large-scale interconnected societies,
which are resilient to resource shortfalls and are technologically respon-
sive to ecological changes.
• At the scale of individuals, increased tolerance brings remarkable emo-
tional sensitivities, but also vulnerabilities to the eects of insecure or
unsupportive development.
• Compensatory attachments beyond those to other people may have
emerged to provide additional emotional support at times of stress.
244 HIDDEN DEPTHS
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CHAPTER 6
Comforting Things: cherished
possessions as sources of social comfort
and security, from the Palaeolithic to
the present
Abstract
All around us, almost all the time, we see objects with no obvious
function that seem to play an important role in our lives. This appar-
ently bizarre obsession with non-functional objects is one of the most
obvious dierences between ourselves and other animals. Our lives
are lled with all kinds of objects, not just those with a practical func-
tion but a whole range of mementos such as photographs, or treas-
ured childhood toys, or necklaces or bracelets whose special place in
our hearts has little to do with physical appearance. Although many
non-industrialised societies are far less materialistic, even constantly
mobile hunting and gathering populations create and attach mean-
ing to objects such as beads, gurines or amulets, which do not have
any immediate practical function.
(Abstract continued on next page)
How to cite this book chapter:
Spikins, P., 2022. Hidden Depths: the origins of human connection. Pp. 255–293. York:
White Rose University Press. DOI: https://doi.org/10.22599/HiddenDepths.g.
License: CC BY-NC 4.0
256 HIDDEN DEPTHS
Here, we consider the extent to which new emotional vulnerabili-
ties may explain our apparently bizarre emotional attachment to
certain treasured things and provide an explanation for the crea-
tion, signicance and movement of many non-functional things in
the archaeological record. We draw together evidence for an often-
overlooked characteristic of cherished possessions – their capacity
to provide comfort and a sense of connection and counteract loneli-
ness. We then consider the characteristics of those kinds of objects
that particularly inspire a sense of comfort and security in our own
societies and the extent to which these characteristics can also be
found in archaeological artefacts from the Upper Palaeolithic. There
will have been many other aspects of meaning that are important in
the creation and use of non-functional things by Palaeolithic soci-
eties. Nonetheless, the signicance of new emotional vulnerabili-
ties, and compensatory attachments to objects, appears to provide
important insights. By moving away from the concept that our own
species – modern humans – must have had a superior mind to other
humans, we can begin to better understand how new vulnerabilities
may have been integral to community resilience.
Understanding how we came to rely on cherished objects to bring
us a sense of emotional security also leads to a better understand-
ing of our human vulnerabilities and our need for warmth and social
connection.
(Abstract continued from previous page)
COMFORTING THINGS 257
Figure 6.1: The treasured and now very shabby teddy bear belonging to
Aileen Rogers and found on the body of her father, known as the Rogers
teddy bear (1910–1915, housed in the Canadian War Museum). Artefact
number 20040015-001 in the Canadian War Museum. For online cata-
logue with further details, see https://www.warmuseum.ca/collections
/artifact/1368588. Photo copyright Canadian War Museum, all right
reserved. Used with permission.
258 HIDDEN DEPTHS
Introduction
In the early years of the 20th century, a Canadian girl called Aileen Rog-
ers owned an unremarkable teddy bear. When Aileen was 10 years old, in
1916, her father, Lieutenant Lawrence Browning Rogers of the 5th Cana-
dian Mounted Ries, joined the army and was sent to the Western Front.
He served as a medic in the trenches of the First World War. Aileen wanted
to make her father feel better about being so far away and, hoping to keep
him safe, she sent him her precious teddy bear in a care package. Lawrence
treasured the bear and always carried it with him every day. He wrote in
a letter:
Tell Aileen I still have the Teddy Bear and I will try to hang on to it for
her. It is dirty and his hind legs are kind of loose but he is still with me.
Tragically, Lawrence was killed at Passchendaele in 1917 when tending the
wounded, and the bear (who by that time had lost both legs and his eyes)
was found with him and returned home. Its story gives us a profound sense
of the love shared by Lawrence and his daughter, represented in her gift of
the bear to him and how he always carried it with him. This small and very
bedraggled teddy bear would later become one of the most signicant arte-
facts in the Canadian War Museum (Figure 6.1).
By sending her father her teddy bear, Aileen sacriced her own source of
emotional support to give something similar to her father. For Lawrence,
holding this bear close made his daughter somehow nearer to him (Bell and
Spikins 2018; Spikins 2015). Our heart goes out to Aileen, and to her father,
Lawrence, who so cared about his daughter that he carried the bear with
him everywhere. This small object tells us a great deal about human love,
loss and vulnerability.
Examples of objects with a similar power to comfort us are all around us
today, as much as they were a hundred years ago. In March 2020, as the UK
went into lockdown at the start of the COVID-19 crisis, for example, treas-
ured objects seemed to take on a particular importance for many people,
despite contributing nothing obvious in practical terms. During this period,
an unusual and generally very low-budget programme became surprisingly
popular. Around 7 million people watched The Repair Shop, a programme
based on the careful repair of cherished but largely valueless possessions
COMFORTING THINGS 259
brought in by members of the public. Many were regularly brought to tears.
Credited with being one of the best programmes on television, The Repair
Shop carefully cared for an assortment of treasured but broken and battered
heirlooms, including stools and seats, teddy bears and varied toys, paint-
ings, boxes and cases, which were restored and returned to their owners.
Why would The Repair Shop be so popular, and especially at the time of
national crisis? Of course, there may be many dierent reasons, including
nostalgia, escapism and a desire to nd alternatives to throwaway culture.
However, amongst these explanations, we cannot help but recognise that,
as humans, we are unique in becoming remarkably attached to all kinds of
valueless or impractical objects, and these attachments seem to become
even more important at certain times. Our emotional relationships to
treasured objects are not easily explained. This ability to form apparently
one-way connections to entirely inanimate things, which cannot repay
our emotional investments as people who care about us might be able to,
might seem to be more of a weakness than a strength. We suer at the loss
of treasured personal possessions, and can invest tremendous time and
eort in protecting and caring for these entirely non-human companions
in our lives.
Our capacities to nd emotional comfort in cherished possessions are
unique, and nothing entirely the same seems to exist in other animals. How-
ever, these tendencies have been rather overlooked as an area of evolution-
ary research, and emotion is only just beginning to feature in archaeological
or evolutionary discussions of past minds (Stade and Gamble 2019). We have
focused, instead, on elevated cognitive capacities – how our increasingly
complex human technology developed, how our aesthetic sense emerged
or how artefacts may act as indicators of status or identity.
It is a little dicult to explain quite why the power of objects to give us a
sense of social safety, and soothe, reassure and comfort us, should be some-
what sidelined. Of course, as we have seen, emotions tend to be thought
of as overly complex, connected to bodily processes rather than mind, and
are even seen as a somewhat woolly area of research in general (see the
introduction to this volume). More than this, however, part of our reticence
towards dealing with our emotional connection to cherished social objects
may lie in our discomfort with our own vulnerability, particularly within a
260 HIDDEN DEPTHS
narrative of our own distant origins. We prefer to see our distant ancestors
as entirely independent and invulnerable (as discussed in Chapter 2). Any
tendency to seek out certain cherished possessions to provide us with reas-
surance thus makes us feel somewhat uncomfortable in demonstrating an
apparently irrational need for such support.
There is certainly a sense of vulnerability about our connection to cherished
things. Indeed, we can be so attached to certain objects that we grieve
deeply if they are broken. We may even nd it dicult to let go of things
and start to hoard objects, as each small letting-go feels too great a loss to
bear. Whilst our cherished personal possessions reect the strength of our
emotional connections to each other, it can also feel as though they bring us
only a step away from hoarding things irrationally, and that to be irrational
is dysfunctional. Emotional vulnerability such as this is rarely recognised as
part of our evolutionary story.
How can an understanding of our emotional brain, and evolutionary
changes in physiological responses aecting tolerance and social sensitiv-
ity, as discussed in Chapters 4 and 5, help us to understand the emergence
of apparently impractical cherished possessions? Might new emotional
vulnerabilities and new needs for connection and support explain a rise in
cherished personal possessions with the emergence of modern humans?
The appearance of widespread non-functional objects
in the archaeological record
That there seems to have been a proliferation of objects of art and adorn-
ment after the emergence of modern humans has been an accepted fea-
ture of the archaeological record for decades. There certainly seems to be a
relationship between the origins of our own species in Africa after 300,000
years ago (discussed in Chapter 5) and the later appearance of widespread
non-functional objects, such as beads or small portable gurines, after
100,000 years ago, with a particular proliferation after 45,000 years ago.
This proliferation has traditionally been seen as an explosion of symbolism,
reecting new ‘modern’ capacities of thinking and expression to such an
extent that it has been seen as the major ‘origin myth’ of our species (Hop-
kinson 2013).
COMFORTING THINGS 261
Apparently non-functional artefacts, often seen as early art or symbol-
ism, certainly existed well before 100,000 years ago. Etched shells from
Trinil in Java date to 500,000 years ago (Joordens et al. 2015), for example.
The Berekhat Ram gurine from Israel, a natural stone whose human-like
gures have been deliberately accentuated, dates to around 250,000 years
ago (d’Errico and Nowell 2000). During the African Middle Stone Age, from
around 400,000 to 300,000 years ago onwards, we see an increasing fre-
quency of apparently symbolic artefacts at various locations (Coulson, Staur-
set, and Walker 2011; Kissel 2017; Kissel and Fuentes 2018) and evidence for
a greater use of colouring materials such as ochres (Brooks et al. 2018).
What we see as ‘symbolic’ artefacts do, however, become much more prev-
alent after 100,000 years ago, which seems to indicate that objects that
are not directly functional have taken on a new signicance. As we have
seen in Chapter 5, alongside changes in cranial and facial anatomy, we see
extended movements of raw materials. This implies increased mobility and
social connection in various places in Africa after 300,000 years ago, associ-
ated with the emergence of anatomically and cognitively ‘modern’ humans.
We see the appearance of beads in North Africa after 100,000 years ago
(Wadley 2021), for example, with particularly notable nds including 13
similar shells of Nassarius gibbosulus found at Taforalt in Morocco dating to
82,000 years ago (Bouzouggar et al. 2007). At Blombos cave in South Africa,
41 marine shells (of Nassarius kraussianus), perforated for suspension and
showing wear from this use, were recovered in deposits dating to around
72,000 years ago (d’Errico, Vanhaeren, and Barton 2009; d’Errico et al. 2005).
Several artefacts that have been seen as clear examples of early art and date
to the period 100,000 to 70,000 years ago, including ochre fragments with
incised crosshatch lines, have been found at Blombos cave and surrounding
sites (Henshilwood et al. 2018; Tylén et al. 2020). Burials with clear examples
of grave goods are seen in the Near East around 100,000 years ago, such
as that at Skhul V, with a wild boar mandible placed in the hands of the
individual who is interred, and that at Quafzeh 11, in which an individual
is buried with fallow deer antlers on their chest (Hovers et al. 2003; Wadley
2021). These burials, as well as nds of perforated marine shells (Glycym-
eris) that had travelled over 40 kilometres and also date to 100,000-year-
old deposits at Quafzeh, are associated with an early migration of modern
humans out of Africa (Bouzouggar et al. 2007). Shells used as ornamentation
262 HIDDEN DEPTHS
are also associated with burial at Border cave in South Africa around 70,000
years ago (d’Errico and Backwell 2016). At this latter site, a perforated Conus
shell is found with a four- to six-month-old infant. Later in the archaeologi-
cal record, marine shells and ostrich eggshell beads, which are identical to
those created and exchanged by modern Jo’huansi, appear in the archae-
ological record at around 42,000 years ago at Border cave in South Africa
(d’Errico et al. 2012). These remain in use until modern times. The wide-
spread use of beads of various forms extends to early Upper Palaeolithic
communities as far apart as China (Wei et al. 2016) and Siberia (Lbova 2021).
Clearly, beads, art and other items of ornamentation are playing newly sig-
nicant and increasingly essential roles in people’s lives.
The most well-known proliferation of beads and other personal ornaments,
as well as small gurines, is that seen in Europe, particularly after 45,000
years ago alongside the movements of modern humans into this region
(Mellars 2005; Vanhaeren and d’Errico 2006). These beads are not only pro-
duced from naturally occurring shells but also created out of mammoth
ivory and soapstone, often circulating over huge areas along extended
networks of communication (Heckel 2018). It is also during this period that
we see the only documented, potentially systematic production of per-
sonal ornaments by Neanderthals in the form of the somewhat contentious
Châtelperronian industries of south-west France (Caron et al. 2011, Gravina
et al. 2018). Though a Neanderthal’s capacity for symbolism is not in doubt
(discussed in Chapter 9), objects such as shell ornaments or portable art are
extremely rare.
It is not dicult to see why a relationship between the emergence of our own
species and the proliferation of symbolic ornamentation and art has always
been seen in terms of a cognitive advance, albeit over a delayed timeframe
from the rst emergence of our species. Cognitive dierences are known to
exist between modern humans and archaic humans such as Neanderthals
(Bruner 2021). Art and ornamentation provide a physical, and aesthetically
remarkable, image of what makes a ‘modern’ mind, seen in terms of a sym-
bolic revolution (Klein 2008). Furthermore, this apparent cognitive advance
seems also to have made new relationships possible. Beads, used as per-
sonal ornamentation in necklaces or on clothing, have traditionally been
interpreted as a mechanism by which connections between groups could
be made and maintained – as demonstrations, perhaps, of ethnic identity
(Gamble 1991; Gamble 1998).
COMFORTING THINGS 263
Much of this progressive narrative does not entirely fall into place, how-
ever. That changes in both anatomy and mobility signicantly predate the
appearance of such personal ornamentation poses a notable issue. Further-
more, whilst capacities for elaborate symbolism are ubiquitous, there is a
pronounced concentration of expression in very specic regions and peri-
ods. Though depictive art dating from after the arrival of modern humans
is found in Indonesia (Aubert et al. 2014), portable art and personal orna-
mentation are particularly widespread with the arrival of modern humans
in Europe. What initially appeared to be a clear distinction between the
symbolic capacities of Neanderthals and those of the early members of our
own species has been eroded in recent years (Homann et al. 2018). Fur-
thermore, personal ornamentation and art emerged in South Africa from
100,000 to 70,000 years ago but then declined, before emerging again after
50,000 years ago. This makes little sense if some critical cognitive threshold
is meant to have been crossed.
Increasingly, there is a sense that there must be other explanations for the
proliferation of symbolism than cognitive superiority, though it is not entirely
clear what these might be. However, the changes in emotional tendencies
discussed in Chapters 4 and 5 provide a potential explanation. Rather than
a cause, personal ornamentation may instead potentially be a side eect
of changes in emotions and increasing social connectivity. Likewise, rather
than a proliferation of symbolism demonstrating some exceptional cogni-
tive advance, such as understanding of symbolism, an ability to be creative,
or an elevated sense of imagination, these capacities might have equally
existed in earlier humans but without an emotional need for elaborately cre-
ated non-functional objects. As discussed in Chapter 5, elevated friendliness
and social sensitivity often brings with it an almost desperate need for com-
fort and social connection. Indeed, we only need to take the most casual of
glances at our close companions, dogs (discussed in Chapter 7) to appreci-
ate how changes associated with domestication aect needs for social con-
text (and it may be no coincidence that dogs are unusual in also sometimes
showing strong attachments to objects). This raises the question of whether
new relationships with objects might be a reection of emotional changes
rather than of elevated capacities in symbolic thought. Increased intergroup
tolerance brings with it emotional vulnerabilities, particularly an extraordi-
nary sensitivity to social surroundings, greater needs for social connection,
and elevated susceptibility to the eects of any lack of attachment security,
social connection or loneliness. Rather than signs of a cognitive advance,
264 HIDDEN DEPTHS
the increasing prevalence of non-functional artefacts and their distribution
within social networks after 100,000 years ago could perhaps be far better
explained, at least in part, by new vulnerabilities occurring with increased
intergroup tolerance.
New emotional relationships to objects?
As humans, we seem to be uniquely capable of forming unusual
compensatory attachments whenever human relationships fail to provide
everything we need. By reaching out past our close human relationships
into realms of real, part-real or entirely imagined companionships, we seem
able to cope better with emotional vulnerabilities. These beyond-human
relationships reect our ability to imagine other social worlds, and an acute
social focus, and they also reect our need for this type of connection.
These unique relationships have not always been part of the human experi-
ence, however.
Might a proliferation of non-functional objects after 100,000 years ago be,
at least in part, explained by new needs for sources of emotional support?
To address this question, we will initially consider the nature of compensa-
tory attachments to objects and how these objects can make us feel com-
forted and secure both as children and as adults, as well as their common
characteristics in modern society. We will then move on to consider cultural
and individual variations in these objects and attachments. Lastly, we will
consider the characteristics of the archaeological record, which might argue
for the signicance of so-called ‘symbolic’ material culture as a source of
emotional comfort and support.
Compensatory attachments to objects in childhood
As we have seen in Chapter 1, our childhood experience can provide us with
important insights into the key elements of our adult emotional responses.
Children’s emotional attachments often present us with a simplied form
of what becomes important to adults and may help us to understand the
possible role of personal ornaments, portable art or other things seen as
symbolic objects which we nd archaeologically.
COMFORTING THINGS 265
As children, we will all have sought compensatory relationships to cope
with the day-to-day experiences of being alone. These compensatory
attachments are many and varied. It is typical in the modern Western indus-
trialised context for children to form close relationships with pets, or become
attached to a particular comforting object such as a blanket or teddy bear,
for example. However, of all of their attachments, it is those that children
make to the rather curious phenomenon of imaginary friends that provide
us with perhaps the most revealing insight into both our capacities and our
needs to nd sources of emotional support, often in what might appear to
be unusual ways. Often sidelined as an area of research, children’s imaginary
friends give us an extraordinary insight into our ideal companions and the
role of our social imagination in bolstering rather fragile human securities.
Children’s imaginary friends used to be thought of as a reection of some
kind of emotional issue or even weakness. However, we now recognise that
they are, instead, an eective means of bolstering emotional resilience.
Imaginary friends appear to us as children when they are most needed. We
tend to develop imaginary friends in response to times of loneliness and
social stress, and to help to improve our sense of connection, self-esteem
and security (Ho 2004). They tend to be supportive, providing compan-
ionship and emotional support, and improving self-esteem. Children with
imaginary friends tend to have better theory of mind abilities, and be more
social (Giménez-Dasí, Pons, and Bender 2016; Taylor et al. 2013), and even
create more interesting and elaborate stories (Trion and Reese 2009). They
straddle the world of reality and imagination and, whilst children are aware
that imaginary friends do not really exist (Taylor and Mottweiler 2008),
imaginary friends seem so real that they provide the emotional support of
an ideal friend (Majors 2013).
The character of imaginary companions may provide us with some impor-
tant insights into ideal supportive gures for children, and how these then
may relate to material objects. These companions are clearly not just a eet-
ing sense of something or someone but are fully formed individuals with
not only physical characteristics but also separate lives and opinions. Taylor
et al. (Taylor et al. 2004: 1178) described several examples, such as a child’s
imaginary friend called Alicia, who was an invisible eight-year-old female
dog, with green fur and blue eyes, who lived under the child’s bed. The child
266 HIDDEN DEPTHS
liked Alicia’s good sense of humour but did not like that no one else could
see her. Another child’s imaginary companion was called Rose and was an
invisible female squirrel, nine years old, with brown fur and hazel eyes, who
lived in a tree in the yard and slept in her imaginary house. Imaginary friends
can be close companions when children are lonely, enabling them to be
more socially condent. Ella, a child of 11, explained how her imaginary
friend Polly helped her become more condent as, without her, she says, ‘I’d
probably feel like very shy, ’cos before when I was like 3 years old, I wouldn’t
talk to anyone and when I got my imaginary friend, I got, I built up my con-
dence and if she wasn’t there I’d probably be quite shy now’ (Majors 2013:
560). Polly emerged when Ella was four years old and her grandmother died
(Majors 2013: 555).
Children’s choice of imaginary friends reects certain common patterns (see
Table 6.1). They often mimic those types of relationships that are most reas-
suring to them, such as with friendly furry animals, with powerful animals
that might protect them, or with friends with combinations of human and
Key characteristics of imaginary companions
Imaginary companions:
– are supportive: they provide companionship, emotional support,
nurturance and help to foster self-esteem (Ho 2004; Taylor 2001)
– cannot be created at will ‘on demand’, but will appear such as in times
of loneliness
– can be human, animal or a combination of the two, or fantasy animals (and
often have human and animal traits) (Taylor, Carlson, and Gerow 2001)
– are common (50–60% of children in modern contexts have imaginary
friends, often several; Ho 2004)
– in animal form tend to be mammals (i.e. able to nurture), and often large
mammals (for example, elephants or lions) (Ho 2004; Taylor, Carlson, and
Gerow 2001)
– are associated with higher levels of theory of mind, creativity, achievement
and absorption in children and the adults they become (Kidd, Rogers, and
Rogers 2010; Wigger, Paxson, and Ryan 2013)
– are known by their creators not to be ‘real’ (Taylor and Mottweiler 2008)
Table 6.1: Characteristics of imaginary companions.
COMFORTING THINGS 267
animal features. Imaginary friends are most commonly human or animal, or
a combination of the two, or even fantasy animals (Taylor et al. 2004: 1178).
For example, one child’s companion, called ‘quack quack’, was a duck with a
human head and hands (Wigger, Paxson, and Ryan 2013). They tend to most
often be mammals (perhaps unsurprising given a shared mammalian nur-
turance response) and particularly large mammals (for example, elephants
or lions).
It is not surprising that medium-sized or large mammals are common imagi-
nary friends. Being mammals, animals such as bears, elephants and horses
share a common nurturing response with us. Also, given their size and intel-
ligence, they seem to be more powerful caregivers or friends than rabbits
or mice might be (Vanutelli and Balconi 2015). Furthermore, social and
empathetic animals may be particularly comforting in ways that humans
sometimes are not. Performance in a stressful test is enhanced more by the
presence of a dog than a friend, for example (Allen et al. 1991). We might
think that our friends could surely understand us better than an animal could.
However, many of our stresses stem from worries about social judgements,
and animals provide support that is more clearly non-judgemental. Medium-
sized and large mammals seem popular choices as imaginary friends, there-
fore. They have the clearest abilities to protect, as well as befriend, and it
seems no coincidence that the animals chosen as companions are those that
seem most capable of understanding how we ourselves feel.
Children’s personied objects share many common features with imaginary
friends, perhaps not surprisingly. Personied objects, such as teddy bears,
dolls or soft or hard animal toys, have personalities of their own and are seen
as protectors (Morris, Reddy, and Bunting 1995). As such, these personied
objects are typically imagined as comforting companions, similar to imagi-
nary friends, albeit ones with a more tangible physical presence. So-called
transitional objects, such as comfort blankets or teddy bears, even seem to
play a crucial function in development, particularly in modern Western soci-
eties. They bridge a transition to independence and to being able to com-
fort oneself in the absence of a human caregiver (Winnicott 1953).
Whilst imaginary friends are protected from the distress of accidental loss,
personied objects benet from provoking a sense of touch and bringing
268 HIDDEN DEPTHS
a certain permanence to children’s lives. Whilst our imagination conjures
up an ideal personality in these objects, such as nurturing caregiver or fun-
loving companion, our sense of touch at the same time responds to the
warmth and softness of favourite personied objects such as teddy bears in
a very bodily way, and the very constancy of such objects provides an addi-
tional sense of security. Given their power to heal distress, it is no surprise
that certain personied objects take on such important emotional roles.
Most parents in a modern Western industrialised context understand only
too well the powerful attachment infants can form to personied objects.
Compensatory attachments to objects in adulthood
We might imagine that tendencies to derive support from personied
objects are discarded as we grow to adulthood. However, it seems that,
rather than disappearing entirely, compensatory attachments to things
that once comforted us seem to simply change in form, and often become
far less visible, perhaps as we feel somewhat embarrassed by the role in
our lives. Where invisible or intangible companions are concerned, beliefs
in spiritual beings show many similarities with childhood imaginary friends
(Mackendrick 2012). Creating in our imagination an ideal caregiver has a
powerful eect in relieving stress and in reducing depression, anxiety and
other emotional disorders (Gilbert 2014; Rockli et al. 2008). Where physi-
cal and tangible replacements for companions are concerned, animal spirits
and amulets or talismans often take similar forms to the animals chosen as
personied objects (Varner 2008). Many people continue to cherish their
childhood teddy bears, and others transfer their source of security into other
forms such as jewellery (Bell and Spikins 2018). In this context, it is perhaps
not surprising that personied objects attain the signicance seen in The
Repair Shop. We learn as children that teddy bears or dolls can be compan-
ions that, despite being inert, feel like they are living beings who are on our
side (Keefer et al. 2012; Keefer, Landau, and Sullivan 2014).
Although each object has its own story and set of beliefs surrounding it,
the way in which attachment objects aect us emotionally is remarkably
similar from teddy bears to cherished gifts to photographs. Like genuine
caregivers, such cherished objects stimulate the soothing neuroendocrine
responses that make us feel cared for. We reach for our keepsakes when
COMFORTING THINGS 269
suering pain and separation (Niemyjska 2019) and they aect us in turn.
Remarkably, simply touching a teddy bear makes us feel more secure and
also in turn to become a nicer person to be around (Tai, Zheng, and Naray-
anan 2011). Cherished personal objects that aect us in this way contribute
to our sense of social safeness, a warm, soothing emotional state that pro-
tects us from stress (Armstrong et al. 2021; Gilbert et al. 2008) and mitigates
against feelings of loneliness (Best et al. 2021). Research even shows brain
changes in people who are lonely over a long time period and nd support
outside of human relationships. In their brains, regions known as the default
network seem to have been particularly strengthened so that the kind of
mentalising, reminiscence and imagination used in personifying objects
can ‘ll the social void’ (Spreng et al. 2020: 1).
Dierent types of objects may provide comfort in dierent ways to dier-
ent people. In some cases, what feels comforting is that the object, such as
a teddy bear, seems to have its own personality or soul, and is capable of
befriending or even protecting us. In other cases, however, objects connect
us to particular people in our lives. A photograph has the most immediate
eect in making us feel like someone might almost be there with us, but
often clothes, or things that loved ones touched or used, often seem to
transport us to their presence in other ways. These kinds of object have a
powerful eect on emotional wellbeing by stimulating our sense of attach-
ment security (Table 6.2), a trait which seems to have become more vulnera-
ble to being disrupted as a result of recent evolutionary changes (described
in Chapters 4 and 5).
Dierences within human populations even hint at evolutionary selective
mechanisms acting on physiological and emotional capacities, which may
have inuenced capacities to nd comfort in things. Though people in gen-
eral tend to anthropomorphise objects at times of stress, those with more
social imagination, and a greater tendency to anthropomorphise objects,
are those who nd the greatest comfort in certain things at times of stress or
loneliness (Keefer 2016). They seem better at visualising a comforting pres-
ence. Certain people are also more prone to feel nostalgic through objects,
apparently relating to dierences in serotonin receptor genes that make
them more sensitive to negative experiences and more driven, therefore,
to nd security in comforting things and memories (Luo et al. 2019). Broad
270 HIDDEN DEPTHS
dierences in social sensitivity, as we have seen in Chapter 5, also have a
genetic component and aect widespread emotional vulnerabilities and
potentials (Assary et al. 2020; Flasbeck et al. 2019).
Like dogs (Kurdek 2008), discussed in Chapter 7, or spiritual beings (Len-
festy and Morgan 2019; Niemyjska and Drat-Ruszczak 2013), cherished
objects can even function emotionally like human attachment gures,
giving us a sense of safety and promoting positive physiological eects
(Keefer, Landau and Sullivan 2014; Keefer et al. 2012). These compensatory
companionships can, in eect, reset our bodies away from competitive
insecure and threat-based systems that damage not only our own health
but also our social relationships, and towards more emotionally connected
and healthy social schemas (Gilbert 2019). As we have seen in Chapters 4
and 5, these changes can aect our tolerance of dierences or strangers,
our willingness to explore, our sense of trust in our close relationships, and
even our immune systems.
Improvements in attachment security
Priming attachment and promoting social safeness with reminders of caring
relationships:
– Thinking of attachments reduces noradrenergic stress response (Bryant
and Chan 2015) and pain (Jakubiak and Feeney 2016).
– Thinking of a romantic attachment gure reduces blood pressure, to the
same extent as having a romantic partner in the room (Bourassa, Ruiz, and
Sbarra 2019).
– Thinking of attachments reduces painfulness of traumatic memories
(Bryant and Foord 2016).
– Priming attachment security reduces negative reactions to out-groups
(Mikulincer and Shaver 2001; Saleem et al. 2015).
– Priming attachment security reduces depression and anxiety (Carnelley
et al. 2018).
– Fostering abilities to feel a sense of social safeness reduces loneliness
(Best 2021).
– Repeated priming of attachment security by various means leads to more
lasting secure attachment (Hudson and Fraley 2018).
Table 6.2: Ways in which objects can improve emotional wellbeing through
fostering attachment security.
COMFORTING THINGS 271
Are there common forms or features to cherished personal objects?
Disentangling which objects are emotionally signicant as a source of social
comfort can be challenging. Clearly, in modern Western societies with a
focus on materialism, objects also full many roles other than being com-
forting or useful, such as being signs of status or achievement, or providing
some sense of comfort in familiarity without bringing with it a sense of sup-
portive social connection. The boundaries between functional objects and
those that provide comfort can also be uid, and our grandfather’s toolkit,
belt or other practical items might be both useful and comforting, for exam-
ple. Moreover, an old belt, a handmade box or cheap jewellery may carry
real emotional signicance for one person, yet appear to another to be of
no value. We may not even acknowledge, or be able to articulate, why some
particular object makes us feel cared for or socially supported.
Research into objects that provide comfort for adults in modern contexts
does, however, provide some support for a continuity of common character-
istics seen in children’s personied objects to those that become signicant
objects for adults. Cherished possessions that provide a signicant source
of comfort often conform to certain forms, such as representing humans
or animals and being easily portable (Bell and Spikins 2018); see Figure 6.2.
Research on over 200 cherished personal objects (see Bell and Spikins 2018),
Figure 6.2: Examples of cherished personal possessions that can provide
comfort. Left: Girl with teddy bear. Lisa Runnels, 2015, via Pixabay:
https://pixabay.com/photos/girl-backside-woods-teddy-bear-961648/.
Right: Brooch with photograph. Penny Spikins, CC BY-NC 4.0.
272 HIDDEN DEPTHS
for example, revealed not only teddy bears kept by adults but other types of
animals as well, such as a toy guinea pig recorded by a student as a constant
stable presence reminding them of friends and family, or jewellery. Certain
jewellery, including animal pendants, are described as providing comfort,
much like speaking to parents or grandparents, and small animals, either
as toys or gurines, are also described as being reminders of the feelings of
being safe at home.
A common theme of continuity with childhood imaginary companions,
described above, with common human or animal gures, albeit often in
portable form, is evident. Objects that act like compensatory attachment
gures also tend to be easily portable and show many signs of wear. Like
our childhood caregiver, we want to be close to them, and touching them
is important. Like imaginary friends, they also often take the form of modi-
ed animals, particularly large mammals, such as teddy bears or animal
pendants. In this case, they are more likely to have ‘a life of their own’ as
something similar to an attachment gure, rather than simply be intangible
reminders of loved ones. Animals seem to have a certain power.
Any object can become meaningful and provide us with a sense of comfort,
much like a caring attachment gure, but some types of objects – those
representing animals, in particular, and which are able to be carried, held or
worn – are more likely to full this role.
Cultural variations
Culture and context aect the types of objects we may become attached
to and, moreover, whether it is objects that we look to to provide us with
comfort or if we seek support elsewhere, such as in companion animals (dis-
cussed in Chapter 7) or even in less tangible imaginary entities.
The role of cherished possessions is seen more clearly in some cultures, and
at certain times. For example, whilst many people still believe that things like
a preserved rabbit’s foot could be ‘lucky’ (Thwaite 2020), historically there
was a much greater function for charms and amulets and a belief that they
had healing and protective properties. Nonetheless, common patterns of
seeking support in something seem resilient, despite the dierences in what
seems the right sort of object to make us feel safe. The tendency for people
COMFORTING THINGS 273
hiding in shelters in the London Blitz of 1940–1941 to carry lucky charms,
including rabbits’ feet, has, perhaps, some similarities to the changing sig-
nicance of personally meaningful objects seen during the COVID-19 crisis.
Whilst, in both cases, many people sought comfort from touching cherished
objects, the form of the objects chosen has changed through time.
There is also much individual variation within any culture. For some people,
cherished possessions, with their power to make us feel safe, secure and
socially connected, are essential to make life bearable, whilst for others they
may come into focus only at certain times of crisis, if at all. They are not always
signicant, or signicant for everyone. Whether some people worry about
appearing vulnerable, nd it dicult to reach out for support, are anxious
about objects being lost or nd a sense of social warmth and safety else-
where, there tends to be considerable variation in the personal signicance
attached to cherished possessions. A certain emotional austerity in mod-
ern contexts can even lead some people to have a sense of disdain for such
things. Nonetheless, whatever the cherished objects, whether a rabbit’s foot
in the London Blitz or a grandfather’s toolbox in the COVID-19 crisis, things
provide comfort, security and safety for some people everywhere. Charms
or talismans, in the form of beads and animal gurines carried or worn by
adults, are found widely across many dierent cultures (Varner 2008).
Attachments outside of human relationships seem to be more necessary,
and the bonds between people and things stronger, in cultural or social
contexts of less social connection and support or where caring gures are
not constantly present (Bowlby 1969; Fortuna et al. 2014). This makes sense
of the relative scarcity of such objects in hunting and gathering communi-
ties. Such societies typically create supportive contexts during childhood
development and adulthood, high levels of attachment security, and con-
stant close physical contact during infancy (Hewlett et al. 2000). These are
also societies with beliefs that include ubiquitous spiritual beings, the pres-
ence of which reduce loneliness. Furthermore, the constraints imposed by
a highly mobile lifestyle and the signicance of sharing and giving that is
so central to modern foraging societies (Lavi and Friesem 2019; Peterson
1993) mean that few things are owned. However, objects continue to be a
source of emotional comfort in these societies, albeit in dierent ways than
in industrialised contexts. Cherished possessions providing some kind of
social comfort are most evident in childhood. Often, as is the case of the
274 HIDDEN DEPTHS
Yamana of Tierra del Fuego, children’s personied objects in hunting and
gathering societies are made from perishable materials such as wood, skins
or grasses (Gusinde 1986) and represent animals or people. Albeit crudely
fashioned from organic materials, such birds, animals or human dolls are
signicant gures in children’s lives. Only in very rare cases would any indi-
cation of these objects remain in the archaeological record (Langley 2020).
Children’s personied playthings, imagined to have their own thoughts,
feelings and identities, are, however, found across all cultures (Hong and
Townes 1976). For adults, highly portable items, such as beads, gurines or
amulets, can be important emotionally (Wiessner 2014). For the Awá of Bra-
zil, the act of making, using and carrying stone arrows is important for their
sense of self (González-Ruibal et al. 2011). Whilst not practical, compared to
alternative hunting weapons that are much more ecient, they are emo-
tionally important, providing a sense of comforting familiarity, identity and
tradition. In many other cases, objects are felt to be signicant spiritually
and have their own living identities. Even in hunting and gathering con-
texts, we see cherished possessions playing a role in many people’s lives,
albeit often being less visible or less relied upon than those we see in mod-
ern industrialised contexts.
The emotional role of cherished possessions, as well as animal compan-
ions or spiritual beings, in keeping us sane may be more important than we
think. Objects are an example of non-human attachments that seem to play
an important, and often unrecognised, role in supporting our emotional
wellbeing, a role that is often left outside of our human evolutionary story.
Art in search of empathy – reappraising the proliferation
of symbolic objects
Anyone who studies Upper Palaeolithic portable art and ornamentation
quickly concludes that much about its precise meaning will remain lost in
time. However, emotional insecurity can have far-reaching eects on us as
individuals (such as limiting our capacities to explore, aecting our immune
system or making us less trusting) and as communities (such as through
hampering a sense of collaboration or willingness to forge relationships
based on high levels of give and take), as discussed in Chapter 5, art and
personal ornamentation may play an important role in counteracting these
insecurities. That cherished objects can provide a sense of security, and even
compensatory attachments where supportive others are lacking, may help
COMFORTING THINGS 275
us to understand some elements of ‘symbolic’ objects, particularly personal
ornaments and portable art.
The timing of a proliferation of ‘symbolic culture’ after populations of mod-
ern humans spread into new regions may be explained in terms of newly
evolved emotional vulnerabilities and new needs for support, rather than
elevated symbolic capacities, imagination or creativity. After modern
humans appear, the proliferation of such objects plausibly follows times of
particular stress, for example. ‘Symbolic’ artefacts appear to particularly pro-
liferate globally after the ‘Adams event’, 42,000 years ago, when we know
that there were major environmental changes and extinction events, as well
as decades of electrical storms, for example (Cooper et al. 2021). It seems
at least plausible that people sought natural forms of comfort in creating
animal-like objects. Moreover, further proliferation of such objects particu-
larly appears as populations move into new and challenging regions of the
globe. The emergence of elaborate art in Europe after 30,000 years ago also
makes sense in terms of a particular context of elevated needs for social
safeness, without any need to rely on narratives of European distinctive-
ness. Aurignacian beads number in their thousands, for example, and mark
the progressive movement of modern humans across Europe (Mellars 2005;
Vanhaeren and d’Errico 2006), when meeting existing archaic populations,
as well as challenging environments, may have placed them under particu-
lar social stress. A proliferation of modern human personal ornamentation
and art during the period of interaction between the two species has also
been seen as a potential response to the presence of Neanderthals them-
selves (Greenbaum et al. 2018). That both species felt a greater need for
compensatory attachments seems entirely plausible.
That what we see as an explosion of art and symbolism may be more related
to a need to ll a void than to some elevated European capacity for imagina-
tion or innovation seems important. We like to see the European creators
of elaborate and highly realistic art as uniquely talented, but an alternative
perspective is one in which they were sensitive and emotionally vulnerable,
within communities that faced challenges from their environments. Ice Age
environments placed remarkable challenges on human communities, with
often-radical shifts in climate leading to severe resource failures and local-
ised extinctions. Moreover, people are likely to have been pushed into lower
population densities or isolated refuges, where connections with others,
and a sense of belonging, were dicult to sustain (Maier and Zimmermann
276 HIDDEN DEPTHS
2017). Furthermore, and perhaps most importantly, there are indications
of at least incipient or occasional hierarchisation in these societies (Pettitt
2020; Vanhaeren and d’Errico 2005; Wengrow and Graeber 2015). Depic-
tive art is extremely rare in the most egalitarian of hunter-gatherer socie-
ties (Bird-David 2006), yet becomes more common in hierarchical societies
where other people are competitors rather than allies, creating physiological
arousal rather than safety. From this perspective, a drive for perfection may
be motivated by insecure striving, and the widespread production and use
of personal ornamentation, gurines and engraved objects a means of bol-
stering social security.
The form of portable art seen in European contexts also makes sense in
terms of sources of emotional support and connection. As we have seen,
children’s imaginary friends take animal, human or combined forms, with
a particular focus on large animals and on mammals as these companions
naturally stimulate our sense of something which can protect us. These
same forms tend to feel most comforting to us as adults, with easily portable
objects that we can touch being most eective at making us feel secure.
Whatever its cultural or individual meaning, portable art may have been
important emotionally in terms of promoting a sense of safety and con-
nection, particularly in dicult times. Similar motifs might, thus, naturally
become prevalent in the more widely discussed cave art.
Some of the earliest and most famous of these portable art pieces come
from south-west Germany, and date to not long after the arrival of modern
humans into the region. Here, gurines of therianthropic (human-animal)
forms or animals have been recovered. Particularly famous examples include
a lion-headed gure from Hohlenstein-Stadel, dating to around 32,000
years ago (Kind et al. 2014; Piprani 2011); see Figure 6.3. Dating to the same
period, at Hohle-Fels there are other, smaller pieces, including a waterbird, a
smaller human-lion gurine, and a horse, for example (Conard 2003), and, at
Vogelherd, a further horse gurine amongst other similar gurines (Dutkie-
wicz, Wolf, and Conard 2018). The form of portable art pieces seems signi-
cant, particularly as, amongst portable art pieces across Europe throughout
the Upper Palaeolithic, large mammals tend to predominate (Figure 6.4).
Characteristics of objects that may have had a spiritual meaning also seem
to have tapped into shared human needs for compensatory attachment
gures (see Table 6.3).
COMFORTING THINGS 277
Like both imaginary friends and personied objects, these objects, quite pos-
sibly held close and carried around for some time, typically represent those
living beings that share a mammalian capacity to responding to our needs,
and the size to viably protect and nurture us, such as mammoth, woolly rhino,
felines, horse and bison. When we consider these famous examples, it is not
hard to see how holding and touching such objects, and sensing a living and
caring soul with them, might give a sense of comfort, stability and constancy.
We have appreciated for some time that personal objects, art and orna-
mentation can be important socially but, perhaps, ignored the emotional
signicance of such items. Attention has tended to focus on how non-
functional items play a role in sharing and exchange systems in small-
scale mobile societies, for example. That the exchange of gifts, like beads
and personal ornaments, functions to sustain networks is clear in the
Figure 6.3: Lion-headed gure from Hohlenstein-Stadel, 40,000–35,000 years
bp. Left: Loewenmensch1. Dagmar Hollmann, CC BY-SA 3.0, via Wikimedia
Commons: https://commons.wikimedia.org/wiki/File:Loewenmensch1.jpg.
Right: Loewenmensch2. Thilo Parg, CC BY-SA 3.0, via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Loewenmensch2.jpg.
278 HIDDEN DEPTHS
Figure 6.4: Small portable art gurines from Vogelherd cave, c. 35,000–30,000
years bp. Top: Horse. Museopedia, CC BY-SA 4.0, via Wikimedia Com-
mons: https://commons.wikimedia.org/wiki/File:Pferd_Vogelherd_Kopie
.jpg. Middle: Cave lion. Hermann Junghans, CC BY-SA 3.0 DE, via Wiki
media Commons: https://commons.wikimedia.org/wiki/File:L%C3%B6we
_Vogelherd-H%C3%B6hle.JPG. Bottom: Mammoth. Thilo Parg, CC BY-SA
3.0, via Wikimedia Commons: https://commons.wikimedia.org/wiki/File
:Vogelherd_Mammut_2006.jpg.
COMFORTING THINGS 279
anthropological context (Wiessner 2002). There is certainly a relationship
between the exchange of items as gifts over many hundreds or thousands
of kilometres and the maintenance of social networks (Ambrose 1998;
Balme and Morse 2006; Dunbar, Gamble, and Gowlett 2014; Gamble, Gowl-
ett, and Dunbar 2011). As Coward explains, since artefacts persist in time,
they can be an aid to memory and a record of social relationships, acting as
the scaold for social understanding and making it possible to extend social
networks (Coward 2016; Donald 2000; Jones 2007). However, the underlying
emotional motivations behind the creation, exchange and use of cherished
objects of art or ornamentation is rarely explored and may lie more in the
realm of emotional comfort than in any calculated social exchange. Gifts
such as beads, in ethnographic contexts, do cement social networks. How-
ever, they also play a far less socially strategic and more personal role in peo-
ple’s lives. More than simply representing identities, they make their wearers
feel connected and safe (Morris and Preston-Whyte 1994). Personal orna-
mentation, such as beads, satisfy a feeling of needing touch and closeness,
perhaps much like modern items like cherished necklaces or bracelets.
Though the appearance of such objects may indicate new social capacities,
they may also tell us about new vulnerabilities and emotional responses,
and responses to social challenges.
Similarities between the characteristics of Upper Palaeolithic portable gurines
and personal objects that promote comfort and security in modern
contexts:
– small size (portable close to the body or able to be suspended next to
the skin)
– preferential selection of large or socially complex mammals as gurines/
depictions (e.g. horse, elephant/mammoth, lion)
– rounded morphology (beyond that of the animal-human depicted): teddy
bears have evolved to be more rounded through time, for example (Morris,
Reddy, and Bunting 1995)
– signs of wear from frequent touch
Table 6.3: Similarities between the characteristics of Upper Palaeolithic
portable gurines and personal objects that promote comfort and security
in modern contexts.
280 HIDDEN DEPTHS
A need for a sense of social safety does not answer all our questions about
so-called art or symbolic objects, of course, and many existing interpreta-
tions have cast important insights into many other elements of their use. As
we have seen in Chapter 3, archaeologists in recent years have increasingly
appreciated the evolutionary basis by which the material culture around us
inuences how our minds work (Malafouris 2015). We have discussed and
debated how material culture inuences how we think (Knappett and Mala-
fouris 2008), how material things can seem to be part of us (Coward 2010) and
create our identities (Miller 2013), and even how material evidence reveals
emotions, particularly those of grief (Tarlow 2012). It has become clear that
objects can have ‘agency’, that is, a power to inuence the world, almost
like living things. Indeed, many ethnographically documented societies do
not draw the rigid distinctions that we do between living things and inani-
mate objects (González-Ruibal 2012). These diering ontologies help us to
understand the relationship between people and art (Ingold 2006; De Cas-
tro 2007). However, the concept of objects as a source of attachment, secu-
rity or emotional comfort is rarely raised. Quite why this should be the case
remains a mystery. Perhaps emotional insecurity seems too raw or too per-
sonal to contemplate, emotional attachments too much connected to bod-
ily responses to seem suciently academic, or vulnerabilities too dicult to
navigate. Whatever the reason, our emotional needs for social safeness and
security, and our abilities to nd this in compensatory attachments, includ-
ing those to objects, are a much-understudied area.
There are also characteristics of portable art and ornamentation that do not
entirely t a role in terms of social safety. Portable art shares many charac-
teristics with cave art, and yet the latter cannot be carried around to provide
a sense of support and is even, in many cases, never seen again after its pro-
duction. Even when we consider art that is portable, we can reect that many
such items may be shared rather than personal, though the connections this
creates may themselves be part of the power of the items. Moreover, many
such objects, including the lion-headed gure, were deliberately destroyed,
something hard to bear in the context of emotional attachments, though
perhaps demonstrating a certain ambiguity about the emotional power
of such objects. Furthermore, it is entirely possible to argue, conversely,
that some elevated social imagination is key to the way in which modern
humans relate to their world, providing a new ability to create social safety
through imagined relationships that may have been restricted prior to our
COMFORTING THINGS 281
own species. After all, we have seen that some children are more imagina-
tive, more social, and more able than others to conjure imaginary friends,
and some adults more prone to nd solace in things, or other compensa-
tory attachments, than others, and that these abilities have some genetic
basis. Elevated social imagination may be prompted by the genetic changes
occurring under self-domestication that we have discussed in Chapter 5.
However, it seems at least plausible that new emotional needs and vulnera-
bilities are part of the explanation for the so-called symbolic explosion with
modern humans.
Perhaps this is the right moment to turn ideas of a progressive elevated
symbolic capacity of modern humans in general, and some elevated
European capacity for the depictive art, on their heads. These may not have
been people with some unique imagination or elevated symbolic capacities
but, rather, sensitive and emotionally vulnerable populations reaching for
objects as a source of support.
Conclusions
Our attachment to cherished possessions, and our capacity to derive comfort
from them, are areas of human experience that are often ignored. However,
when we consider these tendencies in more depth they give us an insight
into several realms of our emotional lives – from our human sensitivity and
need for connection to the exibility of our attachment systems and ways in
which we are able to seek out and nd the social warmth and safeness we
need. Faced with isolation or loneliness, from that caused by harsh environ-
ments or social stresses in the distant past, to wars and pandemics in modern
times, we have remarkable ways of continuing to feel the social connections
we need to thrive even in the absence of the people who care about us.
An understanding of our emotional vulnerabilities and responses suggests
that Upper Palaeolithic portable art and ornamentation may be a product
not only of our creativity but also of our need for a sense of social safety,
connection and understanding. Much as we have experienced ourselves at
times of war or crisis, portable items of Palaeolithic art and ornamentation
reect the responses of people who know what it is to be lonely and inse-
cure about their role in the world. Reaching out to nd a sense of connec-
tion and social safety in objects provides some social comfort. Moreover,
282 HIDDEN DEPTHS
this is not just about emotional wellbeing. When we feel more secure and
socially safe, we are better people to be around, more open to new things,
more tolerant of dierences and perhaps just a little kinder than we would
have been otherwise. In appreciating this, we should perhaps be less hasty
to see anyone as overly sensitive when they feel attached to a precious heir-
loom, or to spend time caring for a treasured object.
Rather than demonstrating a human pinnacle of artistic talent, a prolif-
eration of art and personal ornamentation alongside the global spread of
modern humans may, rather, be a response to the need to accommodate
new emotional vulnerabilities. Cherished objects seen as portable orna-
mentation or art, which become more common after 100,000 years ago
and particularly prolic after 45,000 years ago, may be a product of new
emotional vulnerabilities as much as, or even more than, cognitive advance-
ments. The characteristics of objects which provide us with a sense of social
connection and comfort in modern societies, and similarities to those of new
regionally connected societies after 100,000 years ago, argue for a common
role in providing comfort, alongside whatever other complex meaning they
may hold. Hidden beneath the surface of our natural attraction to aestheti-
cally pleasing things, it becomes evident that changing emotional capacities
and vulnerabilities may prompt particular material objects to begin to play
a new role in people’s lives. As much as cherished personal possessions may
be the most visible aspect of this in the archaeological record, it is reason-
able to imagine whole realms of new compensatory attachments, including
those towards imaginary or spiritual beings, as well as attachments to ani-
mals (explored in Chapter 7).
Many of the cherished personal objects left to us from the Upper Palaeo-
lithic may, in some very human way, share similarities with the Rogers bear.
Though we might not know for whom they provided reassurance or support
or a sense of connection, we might nonetheless have the glimmerings of an
understanding of how.
Key points
• We all share a capacity to nd social comfort in things outside of close
human social relationships, with cherished objects playing an important
role in many of our lives. Compensatory attachments to these objects, as
COMFORTING THINGS 283
well as to other gures, imaginary, inanimate or non-human, can provide
a sense of social safeness and security, and allow us to be more condent
and resilient.
• The archaeological record shows a proliferation of ‘symbolic objects’ at
times of particular stress, after 100,000 years ago, which can be explained
as a response to physiological changes (discussed in Chapter 4 and 5).
These changes enabled both greater external tolerance and approacha-
bility, and were also associated with elevated social and emotional sensi-
tivities. Characteristics of compensatory attachment gures that provide
emotional comfort in modern societies show similarities to new types of
non-functional artefacts appearing at this time.
• New emotional vulnerabilities and sensitivities, rather than elevated and
superior cognitive abilities, may explain a need to derive comfort from
things and the proliferation of ‘art’ or ‘symbolic’ objects in the Upper
Palaeolithic.
284 HIDDEN DEPTHS
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CHAPTER 7
In the Company of Wolves:
compensatory attachments
and the human-dog bond
Abstract
Why are we able to form such an intense emotional bond with other
animals, such as dogs, despite them being so dierent from ourselves
in so many ways? In this chapter, we consider the human emotional
vulnerabilities that drove our close relationships with canids. We
explore how an understanding of compensatory attachments can
provide a new perspective on the inclusion of wolves into human
societies, and the signicance of their dog descendants to our emo-
tional wellbeing today.
We rst explore the roles of dogs in present hunting and gathering
societies, and the potential signicance of bringing wolf companions
into our emotional lives. We nd that, whilst there are considerable
cultural dierences, dogs and people have a capacity to form remark-
ably strong bonds, and dogs can take up a sometimes uncomfort-
able position as almost human.
How to cite this book chapter:
Spikins, P., 2022. Hidden Depths: the origins of human connection. Pp. 295–339. York:
White Rose University Press. DOI: https://doi.org/10.22599/HiddenDepths.h.
License: CC BY-NC 4.0
(Abstract continued on next page)
296 HIDDEN DEPTHS
We then ask whether the domestication of wolves may have been
more inuenced by human emotional needs than we may have cur-
rently assumed. Whilst we tend to view the domestication of wolves
as a process engineered by humans, and indicative of our particular
elevated capabilities or intelligence, our emotional vulnerability and
capacity to make compensatory attachment may have had a key role
to play.
A closer consideration of our shared evolutionary history reveals that
wolves and humans share a deep past of becoming incrementally
closer to each other in terms of social emotional motivations. As we
have seen in Part 1, selection pressures over the last 2 million years
moved human emotional motivations closer to those of highly col-
laborative social carnivores such as wolves, whilst, as we have seen
in Chapters 4 and 5, the period 300,000 to 30,000 years ago brought
new capacities to make novel relationships, and new emotional vul-
nerabilities. During this period, the emotional motivations of wolves
seem to have moved closer to those of humans through living in
close proximity.
Wolf domestication is, perhaps, best seen as a two-way process in
which each species moved to ll an emotional gap in each other’s
lives.
(Abstract continued from previous page)
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 297
Figure 7.1: Artwork: Sympathy, c. 1878, Briton Rivière. Photo: Tate. Used with permission.
298 HIDDEN DEPTHS
Introduction
Why have we developed such close relationships with many species of ani-
mals, and with dogs in particular?
Across human cultures and historical periods, there is often a recognition
that animals can play an important emotional role in our lives. Dogs and
humans can share a remarkably close emotional bond, as shown in this late
19th-century painting by Briton Riviere entitled Sympathy, c. 1878 (Figure
7.1). Despite our evolutionary separation, we seem to understand each other.
We nd dogs almost everywhere that there are people. As early explor-
ers came across indigenous peoples on almost every continent, they also
encountered their dogs (Figure 7.2). The explorers themselves were all too
familiar with dogs as hunting aids, working animals or companions, and the
presence of dogs in people’s lives, even in the farthest reaches of the world,
went largely unnoticed. Yet here is an entirely dierent species, living along-
side and in close relationships with people. That we would develop such a
close relationship with a descendant of wolves is truly remarkable, and not
necessarily easy to explain.
Figure 7.2: Dogs were almost ubiquitous wherever colonists met indige-
nous hunting and gathering populations. This late 19th-century drawing
of an indigenous Australian ‘native encampment’ shows a dog asleep in
the foreground. Native Encampment (detail). Edwin Carton Booth, 1876.
Image: Skinner Prout, Public domain, via Wikimedia Commons: https://
commons.wikimedia.org/wiki/File:Native_Encampment_by_Skinner
_Prout,_from_Australia_(1876,_vol_II).jpg.
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 299
Not only did almost all the hunter-gatherer societies that explorers encoun-
tered share their lives with dogs but occasional accounts also demonstrated
perhaps surprising levels of aection for them. This indicates that these
dogs often played an emotional, rather than simply functional, role in the
people’s lives. The Swedish explorer Lumholtz, cited in Serpell (2016b), for
example, recorded the remarkable level of aection that indigenous hunter-
gatherers in Australia gave to their dogs (dingoes). He notes that the peo-
ples he met treated their dogs:
With greater care than they bestow on their own children. The dingo
is an important member of the family; it sleeps in the huts and gets
plenty to eat, not only of meat but also with fruit. Its master never
strikes, but merely threatens it. He caresses it like a child, eats the
eas o it, and then kisses it on the snout. … When hunting, some-
times it refuses to go any further, and its owner has then to carry it
on his shoulders, a luxury of which it is very fond. (Serpell 2016b: 302)
The anthropologist Betty Meehan later added support to this picture, com-
menting:
It is clear that for some members of the Anbarra community, dogs
and especially pups fullled an important emotional role. Every
Anbarra person loved ‘puppies’, and, as far as we could interpret,
treated them tenderly as if they were human babies. They forced
food upon them, cuddled and talked to them, slept with them and
carried them around. (Meehan, Jones, and Vincent 1999: 100)
Perhaps most tellingly, such accounts demonstrate that dogs could move
into people’s emotional lives where human social connections were some-
times not enough. Meehan continues to describe, for example, the case of a
woman who was an older and less favoured wife who fought with her hus-
band and sister and saw little of her son. She had an unusually large number
of dogs (about 10), with whom she slept at night, often engaging in ani-
mated conversations with them. Her dogs were devoted to her and she, in
turn, carefully fed and cared for them. She even made a small cloth shelter
similar to those made when women were giving birth for one of the female
dogs when she had a litter of puppies (Meehan, Jones, and Vincent 1999).
Stories of dogs transforming people’s lives by being loyal companions and
sources of emotional support are even more common in modern societies.
Dogs are awarded medals for bravery in combat and for risking their lives
to save their owners, and we even build statues to dogs who have shown
300 HIDDEN DEPTHS
extraordinary loyalty. They often take up a role as an ever-present source
of aection and loyalty, and are seen as our ‘best friend’, with us through
all adversity. Dogs traditionally play a role as the willing companions and
source of emotional support for children (Figure 7.1) and, as adults, research
has even shown that, in modern Western societies, only romantic partners
are preferred above our pet dogs as a source of emotional support in times
of stress (Hart and Yamamoto 2016; Meehan, Massavelli, and Pachana 2017).
There are numerous accounts of how dogs have saved people from depres-
sion and loneliness, or isolation, or have transformed their lives in other
ways. Most of us will have experienced some kind of close interaction with
the descendants of tame wolves who now share our lives. Dogs play a sig-
nicant role in people’s lives across the world, whether living as close com-
panions, as is typical in many modern industrial societies, as working dogs,
or as free-ranging dogs associated with human settlements.
What can an understanding of the evolutionary background to human
evolved emotional dispositions contribute to our understanding of how dogs
came to take up such an important role in many of our lives? Might the emo-
tional sensitivities and vulnerabilities we have discussed in Chapters 4 and 5
play a more important role in the emerging relationship between people and
wolves during the Upper Palaeolithic than has previously been assumed?
Here, we rst consider insights from ethnographic contexts before con-
sidering what we can learn from dogs in modern contexts. We reappraise
the archaeological evidence for the ‘domestication’ of wolves to consider if
human emotional vulnerabilities may have played a more signicant role in
bringing dogs into human lives than we generally appreciate.
Dogs in recent ethnographic contexts
As we have seen in Chapter 1, many hunter-gatherer groups keep a range
of dierent animals as pets, including birds and monkeys, and it seems that
these animals play a certain emotional role (Bradshaw 2017). They seem to
stimulate similar types of reactions to those we have to our own infants, and
some of our tendencies to care for animals may stem from the selective value
of demonstrating a reputation as someone sensitive to the needs of the vul-
nerable (Bradshaw 2017) (see Chapter 4). However, dogs are unique in cer-
tain ways in the level of intimacy that they have with human lives (MacLean
et al. 2017). It has been dogs who most clearly adapted themselves to suit life
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 301
with humans, as well as humans who adapted ourselves to suit life with dogs.
They are found sharing their lives with hunting and gathering peoples from
Australia (Figure 7.2) to Tierra del Fuego (Figure 7.3), to East Africa (Figure 7.4).
Dogs as a form of technology
At rst sight, the presence of dogs in ethnographically documented socie-
ties seems to be explained through their usefulness in various tasks. Cer-
tainly, we often see cases in which dogs perform some kind of useful func-
tion (Brougham 2018). Arctic hunter-gatherers depended on teams of dogs
to get around their landscape, and to carry the tools they needed to hunt
and the meat from animals they hunted, for example (Figure 7.5). Further
to the south, in less extreme conditions, North American societies also
used dogs as pack animals using travois (a type of sled using two poles; see
Figure 7.6). Dogs can also help in hunting, in eect making up for the rela-
tively ineective senses we inherit as primates. They have a remarkable
ability to track prey and are also adept at killing small animals. Women in
Central Australian groups commonly used dogs to ush out small game,
Figure 7.3: This photograph, taken around 1930, shows dogs accompa-
nying Selk’nam hunters in Tierra del Fuego. Unknown author. Public
domain, via Wikimedia Commons: https://commons.wikimedia.org/wiki
/File:Selknam_cazando.jpg.
302 HIDDEN DEPTHS
Figure 7.4: Modern Hadzabe of East Africa returning from a hunt with
their dogs. Hadazbe Returning from Hunt. Andreas Lederer, CC BY 2.0, via
Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Hadazbe
_returning_from_hunt.jpg.
Figure 7.5: Inuit coming down Tree River by sled. J. J. O’Neill, CC BY-SA 4.0,
via Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Inuit
_coming_down_Tree_River_by_sled_(38571).jpg.
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 303
for example (Balme and O’Connor 2016). Hunters in lowland neotropics of
South America increase their hunting eciency when hunting medium or
large rodents, such as agoutis or pacas, by using dogs to nd and corner,
or ush out, these animals (Koster 2008; Koster 2009). Moreover, dogs’ highly
attuned senses can be important in defence, such as acting as watchdogs in
the event of intergroup feuding (Koster 2009). Many speculate that, in the
Palaeolithic, dogs may have played a role in defence against the danger-
ous predators such as cave lions or hyenas that were common at the time
(Germonpré, Fedorov, et al. 2017). Dogs are even used in some societies as
a source of wool or furs (Germonpré et al. 2020). Some authors have even
argued that domesticated wolves or proto-dogs played a key role in the
decline of large carnivores during the Ice Age, as well as in the overhunt-
ing of large game, particularly mammoths (Germonpré, Fedorov, et al. 2017;
Shipman 2015a; Shipman 2015b).
However, there is another side to the story.
Figure 7.6: This depiction, published in 1917, shows indigenous North
American hunter-gatherers of the Bison area travelling between encamp-
ments using dogs with travois to carry their loads. Clark Wissler, Public
domain, via Wikimedia Commons: https://commons.wikimedia.org/wiki
/File:The_American_Indian_Fig_11.jpg.
304 HIDDEN DEPTHS
Dogs as playing a role in emotional wellbeing
Ancient dogs may not have been as useful as we might imagine, nonethe-
less. The range of uses of dogs in recent ethnographic contexts may be a lit-
tle misleading as these functions often depend on particular morphologies
or traits that developed well after domestication and are specic to certain
tasks, such as large robust physiques suited to carrying loads. Despite what
we might imagine, unspecialised dogs are not always useful hunting aids.
Dogs that live amongst forest-living hunter-gatherers in Central Africa, for
example, only appreciably increase yields when hunting small animals such
as pouched rats. They can actively interfere with more collaborative hunts
of large game (Lupo 2017). Meehan, considering the use of dogs amongst
the Ambarra of Australia, for example, concludes that most camp dogs were
‘absolutely hopeless at hunting’ (Meehan, Jones, and Vincent 1999: 102).
This is an observation mirrored in other studies (Balme and O’Connor 2016;
Smith and Litcheld 2009), though some argue that dogs may have been
useful in hunting in some contexts (Koungoulos and Fillios 2020). It has been
argued that the ecient hunting of large animals such as kangaroos would
only have been possible in Australia through the introduction of highly bred
and trained European dogs (Meehan, Jones, and Vincent 1999). Dogs may
be useful when tracking and ushing out small game, but seem likely to
have been a hindrance in hunting large game, which they may well have
tended to scare away. Much of the usefulness of dogs for carrying loads may
also be a result of later morphological changes following domestication.
Wolves themselves are agile and nimble, rather than robust, with only dis-
tinctive stocky breeds used in carrying loads in North American contexts
(Brougham 2018). Even some of the potential usefulness of dogs to alert us
to dangers may have developed well after proto-dogs began to share their
lives with humans. Though modern dogs bark frequently, for example, bark-
ing is very rare in wolves (Bradshaw 2017). Many societies, such as the Martu
of Australia, have many dogs but make no use of them to hunt or for any
other economic function (Lupo 2017).
Attitudes towards dogs in small-scale societies can reveal interesting insights
into their potential relationship to humans in the distant past. However, the
picture of human relationships to dogs in such contexts is complicated.
There are certainly examples of contexts in which dogs are treated with dis-
dain and even abuse. Amongst many Central African populations, such as
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 305
the Aka, dogs are often treated harshly (Lupo 2011). Even when considered
useful in hunting, dogs may nonetheless not necessarily be treated with
much respect (Serpell 2016). Many of the ways in which dogs are treated
can also seem alien to our cultural perspective. Dogs may be a source of
food, with the consumption of dogs recorded in both ethnographic and
archaeological contexts, for example (Clutton-Brock 1995; Germonpré,
Lázničková-Galetová, et al. 2017; Serpell 2016a). However, when we look
more deeply, we can see that cultural beliefs about dogs can play a major
role in our attitudes towards them. The Aka, for example, treat dogs harshly
as they are seen as reincarnations of witches or sorcerers, and so danger-
ous (Lupo 2011). These reactions are not, therefore, particularly surprising.
Believing dogs to be dangerous also leads to an equal lack of empathy in
modern contexts (Jordan 1975; Serpell 2016a). As we have seen in Chapter 1,
our tendency to empathise with anybody or any being is much inuenced
by our beliefs about them, and dogs are no dierent. Our modern West-
ern sensibilities can also aect our understanding of what it might mean
in emotional terms for dogs to be seen as food. Eating dogs can be a very
practical response. That there were dogs that were eaten does not neces-
sarily mean that there were not also dogs that were much loved, or even
that dogs that were eaten were not mourned. In some cultures in which
dogs are killed and eaten, this often happens in a ritual context as sacrices
who are mourned (Clutton-Brock 1995). Moreover, even where dogs are
seen as simply a source of food, there are often certain dogs that are seen
as being appropriate for being companions, whilst others are destined to be
eaten (Serpell 2016).
Almost everywhere, dogs are recognised as sharing an intelligence and
emotional capacities not unlike our own (Serpell 2016a).
Rather than their dierences, it is their very similarity to humans that tends
to be the root cause of some of the least empathetic treatment of dogs.
Whilst dogs might seem similar to us in many emotional ways, they cannot
behave according to human social rules or understandings. They lack any
understanding of past or future, understand our language in only the very
crudest of ways, and often behave in ways that are seen by human stand-
ards as immoral or disgusting (Serpell 2016b). They are, thus, often punished
for behaviour that is simply following their instincts because of our own
gut feelings that they should have known better. Being rather too much like
humans also makes them easy scapegoats for displaced aggression (Singer
306 HIDDEN DEPTHS
1978), and it is dogs that are the animals most frequently abused cross-cul-
turally (Gray and Young 2011). For example, amongst the Matinen of Indo-
nesia, whilst men form close relationships with their hunting dogs, carrying
them around and even taking them to bed with them at night, women tend
to treat them aggressively. This is interpreted as a displacement of their frus-
trations at gender inequalities that it is dicult to express overtly (Broch
2008). Dogs found in many archaeological contexts have been subject to
aggression, as demonstrated from tooth loss and tooth fractures (Losey et
al. 2014). Rather than not being similar enough to t into human society,
dogs can be too close for comfort.
For better or worse, dogs often occupy a liminal zone, in some respects ani-
mal but often seen as human-like. If they do not quite t human ideals of
how they ought to behave, or if cultural beliefs impose misplaced motiva-
tions on them, they can be subject to abuse.
The very humanness that can cause aggression towards them also makes
them a frequent source of emotional support, however.
There are several ways in which dogs often play an important emotional
role in recent hunter-gatherer contexts. Dogs are occasionally kept explicitly
as companions, such as is recorded amongst the Iňupiaq (Germonpré et al.
2020). More commonly, however, dogs are frequent playthings and com-
panions for children in almost all foraging contexts (Gray and Young 2011);
see Figure 7.7. They are also often treated as infants, and, perhaps rather
surprisingly from our cultural sensitivities, breastfeeding of puppies is com-
mon (Simoons and Baldwin 1982). These puppies, even as adult dogs, will
be seen as suciently human-like, as having somehow taken on something
important from a person, that the thought of eating them would be repug-
nant (Bradshaw 2017; Serpell 1987). Adult dogs can ll the place of close kin
for whom one would have intense loyalties and go to great lengths to look
after and protect, and who provide an important source of reassurance and
emotional support. It is not unusual for dogs to be present and much cared
for without seeming to perform any useful function. They may be cared for
when ill or injured, provoke a distinct sense of grief at their passing, and are
sometimes buried with their owners, or even individually (Serpell 2016b).
Amongst northern-latitude animistic traditions for which people, animals
and objects all have a distinct spiritual essence, dogs can have a particular
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 307
position within human social relationships. Individual animals of other spe-
cies, such as reindeer, are seen as more of a collective spirit, whilst dogs may
reveal their individual soul (Losey et al. 2011). Rather than all dogs being
almost human, however, it is rather more the case that some dogs reveal
themselves to be human-like. Much like we may view other people with
little regard, yet others as a means of achieving our own ends, and others
we may care deeply for, dogs can occupy very dierent roles in the lives
of humans. Those who were not seen to display a particularly human spirit
may be discarded at death; others may be aorded a human-like burial in
keeping with the human-like soul (Losey et al. 2011). Each dog, like each
human, has their own individual identity.
Sometimes, dogs in ethnographically documented contexts are treated
with what we might view as too much, rather than too little, aection, or at
Figure 7.7: Children, in particular in hunting and gathering contexts, often
develop a close relationship with dogs, especially puppies. This photograph
from the American Museum of Natural History shows Inuit children playing
with their pet dogs, c. 1900. Internet Archive Book Images, no restrictions,
via Wikimedia Commons: https://commons.wikimedia.org/wiki/File:The
_American_Museum_journal_(c1900-(1918))_(18162508871).jpg.
308 HIDDEN DEPTHS
least with too great a leniency, being permitted to behave freely with few
constraints despite the consequences. Perhaps surprisingly, dogs are almost
never trained in the sense we might understand the word of being subject
to positive or negative reinforcement, but rather they are expected to learn
from imitation (Koster 2009), much as is typical of childhood social learn-
ing (Hewlett, Lamb, and Leyendecker 2000). This extreme level of tolerance
towards dogs can be the cause of problems. Serpell describes, for example,
how the Onges from the Andaman Islands are so loving towards their dogs
that they have become a pest, far outnumbering the human population,
creating constant ea infestations and common bites and keeping people
awake at night with continuous barking and howling (Serpell 2016b, after
Cipriani 1966).
The relationship between indigenous Australian hunter-gatherers and din-
goes, an ancient lineage of dog unique to the region, is perhaps one of the
most enlightening.
Dingoes are particularly signicant because their evolutionary history and
behaviours lie somewhere between wolves and modern free-ranging dogs
(Crowther et al. 2014; Miklosi 2014), discussed in more detail in Chapter 8.
Dingoes can hunt, parent and share food collaboratively, much as wolves
do, yet are more tolerant of humans (Miklosi 2014). Dingoes are somewhat
more like wolves in social terms than our other modern dogs, making them
perhaps our best analogy for early proto-dogs. Their abilities to hold human
gaze, important in bonding, lies for example between that of wolves and
dogs (Johnston et al. 2017).
Given that their abilities to share goals and understand human emotional
responses are somewhat reduced compared to ‘domestic’ dogs, that some
of the closest relationships between humans and dogs are between indig-
enous Australian populations and dingoes is perhaps surprising. It is almost
as if, by being less useful, they become more signicant emotionally.
Perhaps more than any other dogs seen in ethnographic contexts, it is din-
goes that were most clearly lling an emotional gap in people’s lives. Whilst
there is some evidence that, after European colonisation, imported domesti-
cated dogs may have been useful hunting aids (Koungoulos and Fillios 2020),
possibly even for large game such as kangaroos, the usefulness of dingoes in
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 309
hunting is much less evident. Their use as a type of technology was limited.
Dingoes mostly served a function as hunting aids for women hunting small
game, and as ‘blankets’, and did not hunt large game or carry loads (Balme
and O’Connor 2016; Smith and Litcheld 2009). In contrast, it is their role as
companions and as a source of emotional support that is the most evident
(Meehan, Jones, and Vincent 1999). Dingo puppies would commonly be
breastfed and be companions and playthings for children, and treated with a
great deal of aection (Balme and O’Connor 2016). Dingoes in Anbarra soci-
ety in Arnhem Land provided a psychological defence against malevolent
spirits, and played a particularly important role as companions for children
and the elderly (Meehan, Jones, and Vincent 1999). Dingoes appear to have
been treated ‘almost as members of the family rather than as personal prop-
erty’ (Gunn, Whear, and Douglas 2010, after Berndt and Berndt 1988).
Despite their intimate relationship with people, dingoes were far from
domesticated as we might understand the term. Adults were usually not
deliberately fed but would scavenge for food, could suer from diseases
and could often be undernourished (Smith and Licheld 2009). Their alia-
tion with people would often loosen as they became adult dogs, when they
became less appealing to humans. Except in the case of a few favoured ani-
mals, adult dogs would usually return to free-ranging communities, which
lived in more distant association with human groups (Gunn, Whear, and
Douglas 2010). Only in a few rare circumstances were breeding adult popu-
lations integrated into indigenous communities (Smith and Lictheld 2009).
This relationship with dingoes demonstrates how emotionally close people
can come to animals that are eectively ‘wild’ without these groups being
signicantly dependent on each other, economically or practically.
Overall, it is clear that in hunting and gathering contexts, as in modern West-
ern industrialised societies, dogs can play an important role in making the
emotional context of childhood feel more supportive and in being a friend to
adults when they feel they need one. Moreover, where there is a lack of con-
nection or a sense of loneliness in human relationships, dogs can provide the
emotional support to ll the gap. As we have seen in Chapter 5, this is not just
important for individuals but for societies as a whole. Bolstering our sense
of being socially safe through attachments to dogs makes individuals both
more resilient, and better able to develop relationships based on trust and
generosity, and also fosters more social collaboration at a community level.
310 HIDDEN DEPTHS
Studies of the psychological signicance of dogs in modern contexts can
help us to understand the emotional role that they can play.
Dogs as sources of emotional support in modern
industrialised contexts
What drives the remarkable intimacy between humans and dogs? Recent
research in modern industrialised contexts has given us some important
insights. We have discovered that dogs share many of our most critical emo-
tional capacities. They are emotionally capable of forming strong bonds of
love and aection, and can understand and empathise with many of our
feelings (Albuquerque et al. 2016; Kis et al. 2017; Nagasawa et al. 2015; Turc-
sán et al. 2015). Dogs synchronise their stress levels with ours (Sundman et
al. 2019), and even share a similar physiological reaction to crying babies
(Yong and Ruman 2014). A study of children in Spain, aged between six
and 13, showed that they rated dogs as similar to humans on scores of cog-
nitive and emotional capacities, such as intelligence and abilities to feel pain
or happiness, for example (Menor-Campos, Hawkins, and Williams 2018). To
them, dogs did not seem to be so dierent to humans.
Dogs can act in lieu of people as a source of emotional support in adults (as
discussed in Chapter 5). They can even act in a way that is psychologically a
little like parents as attachment gures. This means that, when we are with
a dog with which we are emotionally attached, the release of opiates like
oxytocin and beta endorphin make us feel safe and calm (Beetz et al. 2012;
Kis, Ciobica, and Topál 2017; Kis et al. 2017). They make us feel loved and
cared for, provide a ‘safe haven’ and give us the condence and self-esteem
to approach any diculties we face (Kurdek 2008; MacLean and Hare 2015).
Dogs can have a signicant impact on improving emotional wellbeing
(Brooks et al. 2018). As we have seen in Chapter 5, this is important not
just for individuals but for societies as a whole, as bolstering our sense of
social safety through the emotional support of dogs both makes individuals
more resilient and fosters more social collaboration within communities. In
Chapter 6, we discussed how a closer attachment to cherished objects
seemed to have developed during the COVID-19 lockdown in the UK.
Alongside many other pets, pet dogs were even more important, maintain-
ing emotional wellbeing for many people (Ratschen et al. 2020; Shoesmith
et al. 2021).
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 311
The support provided by dogs not only compensates for where social rela-
tionships may be decient but also complements the support of people
around us, even when supportive relationships are abundant. That dogs
are not judgemental can sometimes mean that they are more eective
means of emotional support in certain situations, for example. When hav-
ing to complete a stressful or demanding task, it is often the company of
a dog that is even more benecial than that of a friend (Allen et al. 1991).
That dogs share with us a beating heart and a capacity to care about us,
to express aection and to show a certain level of empathy, can have a
profound eect. Far from being a passive part of our lives or an object of
functional use, dogs in modern societies certainly seem to be playing an
important emotional role, and providing a means by which we are better
able to cope with our own emotional vulnerabilities. They may ll a specic
emotional void at the particular point it appears, but dogs also full many
of our basic emotional needs and respond to vulnerabilities that are part of
our everyday lives. As we have seen in Chapter 5, dogs, or other sources of
feelings of warmth, security and social safeness, do not just make us indi-
vidually healthier but also make societies more collaborative and resilient.
Much like comforting objects, discussed in Chapter 6, our close relation-
ships with dogs in modern industrialised contexts tells us about a remark-
able human capacity to nd comfort, warmth and emotional safety outside
of close human bonds. Much like our dependence on comforting objects
today, our relationships with pet dogs also illustrates the additional needs
for comfort and social support that our rather disconnected and isolated
modern societies impose.
The process by which wolves came to be ‘tame’ is often seen as one that
demonstrates the elevated intelligence of modern humans, and a new drive
and capacity to control the environment, including animals, to our own
ends. Could tame wolves or early dogs have, instead, been incorporated
into human societies as a response to new emotional vulnerabilities?
Reappraising the domestication of wolves
from the perspective of emotional vulnerabilities
Interpretation of the mechanisms underlying wolf domestication to date
have tended to emphasise the practical or economic usefulness of either
side of the wolf–human relationship. Wolves are seen as domesticated
312 HIDDEN DEPTHS
through being functionally useful for people (as described above) whose
new elevated cognitive abilities paved the way for domestication, and peo-
ple are seen as serving as a source of scraps of food to scavenge (Jung and
Pörtl 2018).
A reappraisal of the archaeological evidence, in the context of our under-
standing of the evolution of our increasingly socially attuned and yet
emotionally vulnerable minds, allows us to cast a new perspective on the so-
called ‘domestication’ of wolves. Rather than elevated cognitive capacities,
and economic drivers, it may have been human emotional vulnerabilities,
alongside similar sensitivities in wolves themselves, that drove strong bonds
between humans and wolves.
Archaeological evidence
Research into wolf domestication has tended to rst focus on the timing
of wolf domestication as the primary means of understanding how it
occurred. The exact timing of the sustained domestication of wolves
remains in debate, and the process almost certainly took many thousands
of years. Genetic evidence, for example, suggests that there were very
probably multiple points of domestication across Europe and Asia, as well
as many instances of continued interbreeding between proto-dogs and
wolves (Caspermeyer 2017; Godinho et al. 2011; Skoglund et al. 2015). In
North America, for example, around half of grey wolves have a black coat
coloration that came from interbreeding with populations of dogs arriv-
ing with humans into the continent (Bradshaw 2017). The earliest traceable
genetic ancestor of modern dogs lived around 15,000 to 20,000 years ago
(Cagan and Blass 2016; Druzhkova et al. 2013; Skoglund et al. 2015). How-
ever, the complexity of intermixing within the genetic record means that
the rst wolves came to live in close proximity to humans many thousands
of years prior to this point (Freedman and Wayne 2017). Either earlier proto-
dogs living in close proximity to humans left no direct descendants or the
confusion created by high degrees of interbreeding with wolf populations
makes their existence almost impossible to identify (Larson et al. 2012; Sko-
glund et al. 2015).
Potential evidence exists of morphological changes, typical of domes-
tication (or, as we have seen in Chapter 4, something best described as
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 313
increasing tolerance or tameness) occurring in wolves not long after modern
humans entered Europe. Wolves, or perhaps even proto-dogs, dating to
around 30,000 years ago in Europe, show a reduction in size and in snout
length, for example (Germonpré, Lázničková-Galetová, and Sablin 2012).
However, these interpretations remain somewhat contentious, as it may
be dicult to dierentiate such changes from morphologies that may have
existed in contemporary wolf populations (Boudadi-Maligne and Escar-
guel 2014; Germonpré et al. 2015; Morey 2014). Nonetheless, a proto-dog
from Razboinichya cave in Siberia, dated to 33,000 years ago and similar to
those in Europe, also shares many features with modern dogs, rather than
wolves (Druzhkova et al. 2013; Ovodov et al. 2011). Entirely conclusive evi-
dence may be dicult to nd, but there is certainly suggestive evidence
that wolves took up close relationships with humans not long after modern
humans arrived in Europe.
It is what archaeological evidence can tell us about the nature of the rela-
tionship between humans and dogs that is perhaps the most interesting.
Perhaps surprisingly, there seems to be limited evidence that dogs perform
a functional role, though this evidence might, of course, be rather dicult
to nd. Neolithic dogs from Siberia may show certain signs of being used as
load animals through osteoarthritic changes in the limbs (Losey et al. 2011).
However, these results remain speculative. Equally, these are late examples
and, as we have seen, load animals tend to be a rather specialised breed.
Specialised forms of dog do not seem to appear until late in the archaeo-
logical record. The earliest possible example of a specic form of dog is that
of Late Glacial small dogs found the south-west (Pont d’Ambon and Mon-
tespan) and north of France (Le Closeau), of which 49 examples date from
15,000 years ago onwards (Pionnier-Capitan et al. 2011). However, whether
these dogs are notably smaller than wolves as a side eect of domestica-
tion or through some functional advantage of a smaller size that made life
alongside humans more successful, such as for catching rodents or being
less costly to feed, is dicult to determine.
Evidence for how people treated their dogs is more revealing. That the
deaths of dogs or proto-dogs prompted certain rituals or practices gives us
some indication of, at least, intense conicting feelings towards dogs and,
in many cases, what was likely to have been a sense of grief at their passing.
314 HIDDEN DEPTHS
The act of burying a dog at death, or carrying out a particular ritual, much
as we might for a human, almost certainly indicates an appreciation of the
unique identity of dogs within human lives. Early proto-dogs or wolves, dat-
ing to around 30,000 years ago, found at Předmostí in the Czech Repub-
lic, for example, include one individual found with a large bone inserted
between its jaws after death (Germonpré, Lázničková-Galetová, and Sablin
2012), potential evidence of a certain human drive to nurture this animal
with food. Several contemporary proto-dogs also have holes that have been
incised into the crania, which have been interpreted as a potential intention
to allow their souls to be released into an afterlife (Germonpré, Lázničková-
Galetová, and Sablin 2012).
Somewhat later in time, we see the appearance of dog burials. Dogs may
have been buried as spiritual protectors or as beings with a human-like soul,
and we may never entirely understand the motivations for interring dogs as
if they were humans. It is not uncommon for certain groups, such as the Aka,
who usually accord little respect or dignity to dogs, to nonetheless some-
times bury a particularly good hunting dog as a sign of respect for their
contribution (Serpell 2016b). Nonetheless, many burials do appear to dem-
onstrate the particularly signicant role of dogs in people’s lives, a little like
that of a family member (Morey 2006).
Probably the earliest accepted dog burial is that of a dog buried within a
double grave of a 50-year-old man, a 20- to 25-year-old woman, and another
dog, at Bonn-Oberkassel in Germany around 14,000 years ago (Janssens et
al. 2018; Morey 2010). The site was excavated over a hundred years ago,
making the precise dating of this burial, and the details of placement of the
people and the dog, rather uncertain. However, it is not details of stratigra-
phy or orientation of remains that are the most signicant element of this
burial. Instead, it is that the remains document probably one of the earliest
cases of apparent care that seems to have been given to a dog during a
lengthy period of illness. The dog, a juvenile who died at about 27 to 28
weeks, suered from canine distemper, as well as periodontal disease (prob-
ably related to associated immune deciency). It was severely ill from 19
weeks onwards, and would have been unlikely to survive without consider-
able care, which has been interpreted as an indication of a close emotional
bond with the people who must have looked after it (Janssens et al. 2018).
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 315
Dog burials become more common from the end of the glacial period. More
securely dated dog burials have been recovered at the North American sites
of Koster and Stillwell II in Illinois dating from around 10,000 years ago (Perri
et al. 2019). Here, three dogs were buried in clearly demarcated pits, with
a certain level of care. Dogs must have accompanied some of the earliest
colonists into the Americas (Perri et al. 2021).
The practice of burying certain dogs at death is seen in many contexts
(Morey 2006). Some of the most famous dog burials date to the Holocene.
Perhaps the most well known are those from the Late Mesolithic site of
Skateholm in Sweden, dating to about 6,500 to 5,500bp. These burials seem
to t with the perception of dogs as remarkably human-like seen in animis-
tic contexts (Larsson 1990). Within the large hunter-gatherer cemetery at
Skateholm, there are 14 dog burials, each of which seems to indicate a dog
with a certain status or personality who may have been signicant at the
time. In one case, a woman and dog were buried together, with the body of
the dog situated above the women’s legs. In another case, a single dog was
buried alone, and was interred with more grave goods than other human
burials, including int akes, red deer antler and a stone hammer. Red ochre
was also often scattered over the dogs’ corpses (Larsson 1990; Morey 2010).
Robert Losey has interpreted dog burials by Holocene foragers socie-
ties in the Cis-Baikal as signs of dogs that were seen as having human-like
souls (Losey et al. 2011). Further potential evidence for care of an injured
dog comes from this region, where a dog (or proto-dog/wolf) found at
Ust’-Khaita and dated to around 12,000 years ago had suered a puncture
wound to the crania and scapula that had healed, possibly suggesting care
from humans (Losey et al. 2013). In an animistic understanding of the world,
typical of many hunting and gathering societies, certain dogs may have
shown themselves to be human-like and, thus, a human-like treatment at
death may also have seemed most appropriate. Perhaps for this reason, dog
burials seem to be particularly associated with forager societies in the Cis-
Baikal, rather than later pastoralists whose worldviews may have been less
in keeping with attributing a human agency to animals (Losey et al. 2013).
A dog at Pad’-Kalashnikova, dating to around 6,900 years ago, was indi-
vidually buried in a sitting or crouched position, for example (Figure 7.8).
Another, buried at Ust’-Belaia around 6,800 years ago, was buried wearing a
316 HIDDEN DEPTHS
necklace of red deer teeth, as well as some antler and other faunal remains
(Losey et al. 2013); see Figure 7.9.
Other burials apparently indicating much aection for dogs include that in a
Natuan (pre- or early agricultural) context at Ein Mallaha, in Israel. Here, the
11,000- to 12,000-year-old burial of a puppy was associated with an elderly
Figure 7.8: Prehistoric dog burial from Pad’-Kalashnikova. Image copyright
Losey et al. (2013): https://doi.org/10.1371/journal.pone.0063740.g006.
Shared under the Creative Commons Attribution Licence CC BY 4.0.
Figure 7.9: Prehistoric dog burial from Ust’-Belaia, Siberia. Image copyright
Losey et al. (2013): https://doi.org/10.1371/journal.pone.0063740.g007.
Shared under the Creative Commons Attribution Licence CC BY 4.0.
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 317
individual whose left wrist was partially under the forehead of the puppy,
interpreted as denoting an aectionate relationship (Morey 2010).
Other canids also played an apparently emotionally signicant role in peo-
ple’s lives, even if this did not lead to full domestication. There are even cases
where foxes have been buried in a human-like way. An extinct fox was found
buried alongside humans in the 2,000- to 3,000-year-old hunter-gatherer
cemetery of Loma de los Muertos in Patagonia, for example, interpreted as
indicating some particular emotional relationship, or recognition of the fox
as somehow human-like (Prates 2014). Similarly, a burial of a red fox, dated
to 14,000 years ago, was also found alongside human graves in a pre-Neo-
lithic context at ’Uyun al-Hammam in Israel (Maher et al. 2011). These foxes
may have been, at least in some understanding of the term, friendly towards
humans. Whilst it is dogs who have particularly taken up a widespread role
in our lives, canids in general share many emotional similarities and needs
to humans as close relationships with foxes, as well as their ready domes-
tication (discussed in Chapters 4 and 5) illustrate. There are often cases
of orphaned foxes in recent times that develop a close relationship with
humans. Clarence Birdseye, writing in 1955, described adopting an orphan
wild Peruvian fox when living near Lima, for example, which he described as
being ‘as tame as any dog or cat’ (Birdseye 1956). The fox, named Susie, lived
with Clarence and his wife for over 18 months and was aectionate with
them, calling for them when needing assistance, though always remaining
nervous of strangers. Other burial evidence suggests an even wider range of
animals in close relationship with people. Most famously, cats develop close
relationships without being ‘domesticated’. At the pre-pottery Neolithic site
of Shillourokambus in Cyprus, an eight-month-old cat was buried with its
presumed human owner around 9,500 years ago (Vigne et al. 2004).
Artefacts can also provide important clues to human–wolf relationships.
The depiction of dogs or wolves, or the use of their bones, in personal orna-
ments may also indicate a close relationship to humans. Wolf or dog teeth
are commonly suspended as jewellery in the Upper Palaeolithic, far more
frequently than those of food animals such as reindeer, or even of other car-
nivores (Germonpré, Lázničková-Galetová, and Sablin 2012). Wolves often
carry particular important meanings to people in North American mythol-
ogy (Pierotti and Fogg 2017), and the teeth of dogs themselves might
318 HIDDEN DEPTHS
potentially have been worn in reection of their signicance, much like
human teeth were also suspended as jewellery during the same period.
Across the prehistoric world, dogs are also sometimes depicted within
art. At the pre-Neolithic site of Shuwaymis in Saudi Arabia, for example, a
rock art frieze depicts people hunting horses with several dogs, some of
which are on leads (Guagnin, Perri, and Petraglia 2018). However, in Upper
Palaeolithic Europe, in contrast, dogs are conspicuous by their near complete
absence. Like humans, dogs are rarely, if ever, depicted and, if they are, it
is rather schematically, in contrast to the careful and evocative images
made of animals such as horse and bison (Montañés 2018). Within the
hundreds of images of other animals in the corpus of European Upper Pal-
aeolithic art, only a few depictions of wolves exist. These include a cave
art depiction of a wolf with a reindeer, dated to 11,000bp, at Altxerri in
northern Spain (Sieveking 1979) and one at Font de Gaume in south-west
France, dated to 17,000 years ago, as well as occasional depictions on pla-
quettes. This unwillingness to depict wolves or dogs, seen also in Australian
Aboriginal art (Gunn, Whear, and Douglas 2010), may reect an ideological
discomfort with the imposition of otherness that depiction imposes (Bird-
David 2006).
The timing and location of some of the earliest evidence of a close rela-
tionship between humans and dogs may also be a telling indicator of their
role. As we have seen in Chapter 6, survival in Ice Age Europe and Siberia
placed not only economic but also emotional pressures on human popula-
tions, conditions that also fostered a closer relationship to wolves. Whilst
these relationships with wolves may have brought functional advantages
such as load-carrying or hunting in cold northern climates, these are only
likely to have developed well after early domestication. Furthermore, it
is in those contexts in which we see early evidence of potential inequali-
ties. Early Upper Palaeolithic (Gravettian and Epigravettian) sites in Central
and Eastern Europe, for example, demonstrate dierential burial types,
specialisation in production and/or remains of monumental architecture,
which may indicate some level of ranking, even if seasonal or occasional
(Wengrow and Graeber 2015). It is possible that dogs were some type of
prestige possession (Germonpré et al. 2020), although elevated stresses
imposed by ranked hierarchies (discussed in Chapter 5), on top of existing
emotional vulnerabilities, may perhaps better explain their incorporation
into human communities.
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 319
Archaeologists have tended to focus on the functional elements of the
transformation of wolves into domestic dogs and on the precise timing of
domestication. Much of the archaeological evidence tells a rather dierent
and perhaps more important story, however, of the emerging and complex
emotional bond between humans and increasingly tame wolves as each
adapted to each other (Losey, Nomokonova, and Fleming 2018).
Similar evolutionary pathways in dogs and humans
It perhaps is not dicult to see, on reection, that human emotional vulner-
abilities and need for compensatory attachments (discussed in Chapters 4
and 5) may be an important part of the explanation for why people drew
animals such as wolves more closely into their lives. As we have seen,
compensatory attachment gures such as dogs can ll a gap in people’s
lives. The emotional support and companionship they provide can, in bol-
stering a sense of emotional security, boost condence, an ability to be
social, abilities to explore, and resilience to depression, as well as aecting
immune systems and health in many ways. Even when there is no emotional
‘gap’ in people’s lives, dogs can give us a sense of belonging, friendship and,
even, community. They can make us better people.
The roots of our close relationships lie far back beyond the transition we
know as domestication. Important similarities exist between wolves/dogs
and humans, despite the evolutionary distance, which may explain what
drew humans and wolves to each other. A closer consideration reveals that
the stage was set for a particularly close relationship well before the start
of the Upper Palaeolithic. As we have seen in Chapter 1, between around
3 million and 1 million years ago, early humans moved into a similar niche
to that already occupied by social carnivores. This transition was made pos-
sible through emotional changes, not simply changes in analytical thinking,
bringing human emotional motivations more into line with those of highly
collaborative social carnivores. From here came the roots of our social simi-
larities with wolves. Our shared heritage as collaborative hunters gives us
a remarkable loyalty to group members, inhibitory control over emotions,
the drives to share food and care for infants and the vulnerable, a sense of
justice, creative play (even as adults), social understanding, and strong moti-
vations to collaborate toward shared goals. Wolves, like humans, are highly
sensitive to the emotions of individuals around them, and care deeply about
the wellbeing of everyone in their living group (Table 7.1).
320 HIDDEN DEPTHS
Other transformations in emotional motivations and the nature of social
connections occurred later, and at somewhat dierent periods for modern
humans and wolves. For humans, it was changes in tolerance, and human
emotional dispositions more broadly, beginning in Africa after 300,000 years
ago and described in Chapter 5, which paved the way for new relationships.
At this stage, people seem to have become more condent in new situations
and less stressed by unfamiliarity, whilst at the same time being more socially
and emotionally sensitive. For dogs, it was only once humans reached Europe
and Asia, where they interacted with wolves, that we see the same types of
changes taking place as they interacted more closely with humans. A cas-
cade of changes resulting from alterations in key genes provoked changes
in proto-dogs to also make them more friendly to people, more open to new
experiences, more sensitive to their social environment and, in turn, more
vulnerable to a lack of social connection and support; see Table 7.2.
Whilst, of course, there are profound dierences, important social and emo-
tional changes took place within both modern humans and proto-dogs. The
As a result of shared heritage as highly social and collaborative hunters, people
and wolves (as well as dogs) share:
– motivations to take risk on behalf of others and loyalty to other members
of the group
– motivations to share (wolves share food fairly, though this capacity is lost in
dogs) (Marshall-Pescini et al. 2017)
– inhibitory control (Marshall-Pescini, Virányi, and Range 2015)
– motivations to care for vulnerable young, even if not direct ospring (seen
most clearly in collaborative parenting in wolves; however, dogs can be
caring and protective of other young including human young)
– motivations to collaborate in a shared goal (Range and Virányi 2014)
– sense of fairness and justice (Essler, Marshall-Pescini, and Range 2017;
Palagi et al. 2016; Pierce and Beko 2012)
– social imaginative play, even as adults (Beko 2001)
– social intelligence, including at least some rudimentary understanding of
others’ perspectives (Heberlein et al. 2016)
– sensitivity to facial expressions as indicators of emotion (Hobkirk 2019)
Table 7.1: Ancient shared emotional capacities and drives between humans
and wolves (as well as dogs).
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 321
same capacities for relatively rapid evolutionary changes in the hypotha-
lamic–pituitary–adrenal (HPA) axis existed in both species (Jung and Pörtl
2018). Within the broad characteristics already associated with domestica-
tion/self-domestication (including decreased aggression, increased gre-
gariousness, modied adrenal gland function, changes in neurotransmitter
levels, a prolonged juvenile period), dogs and humans share specic genetic
changes (discussed Chapter 7), such as changes associated with hypersocia-
bility (vonHoldt et al. 2017). Moreover, dogs and humans appear to share
As a result of a shared transition to increased tolerance/friendliness, humans and
dogs both show:
– tendencies to seek out novelty (Gácsi et al. 2005; Miklosi 2014)
– abilities to follow subtle gestural and emotional clues (Hare and Tomasello
2005)
– hypersociability, e.g. infants motivated to explore new relationships with
strangers (Shuldiner et al. 2017; Feuerbacher and Wynne 2017), and there
are similar genetic underpinnings to human and dog hypersociability
(vonHoldt et al. 2017)
– a period of socialisation in infancy, which guides orientations and expecta-
tions towards others in adulthood (Miklosi 2014)
– sensitivity/vulnerability to a lack of social support and emotional connec-
tion (Miklosi 2014)
– a tendency to look for help from others to solve problems (Miklósi et al.
2003; Gácsi et al. 2005)
– abilities to have a dual identity – relating in one way to one species and in
dierent ways to another (Bradshaw 2017), including abilities to relate to
humans/dogs as alternative attachment gures (Kis et al. 2014; Nagasawa
et al. 2015; Thielke and Udell 2017)
– tendencies to seek compensatory attachments in objects (dogs can also
have attachment objects) (unpublished survey, University of Bristol Veteri-
nary school)
– attention to eye gaze, and abilities to form attachments and oxytocin-
related bonds with other species (Kis et al. 2014; Kis et al. 2017; Nagasawa
et al. 2015; Topál et al. 2005). Alongside these changes we also see changes
in facial musculature allowing expressions of vulnerability (Raghanti 2019)
Table 7.2: Recent shared emotional capacities and drives between humans
and dogs.
322 HIDDEN DEPTHS
two further evolutionary adaptations that facilitate their relationships with
each other. Firstly, changes in particular parts of the brain aecting desires
to please/conformity, focus on others versus self, and increased social sen-
sitivity (the ventral striatum) seem to aect both species (Raghanti 2019).
Secondly, changes in the eye muscles and expressivity around the eye
(aecting abilities to show vulnerability or make ‘puppy dog eyes’) may also
have aected both species (Godinho, Spikins, and O’Higgins 2018; Kaminski
et al. 2019; Raghanti 2019).
Whilst so dierent in so many ways, some aspects of both human and dog
emotional motivations and sensitivities have converged in evolutionary
terms (Figure 7.10). Both at several million years ago, and more recently,
both species have been those that took evolutionary pathways towards
Figure 7.10: Illustration showing evolutionary convergence of elements
of human and wolf–dog social emotional dispositions. Penny Spikins,
CC BY-NC 4.0.
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 323
rstly increasing collaboration and secondly increased tolerance and
approachability. Other species took dierent routes. Some hominin ances-
tors followed less-collaborative paths that were not dependent on collabo-
rative hunting, whilst some canids became solitary hunters. Likewise, some
archaic humans did not turn towards the external focus and emotional sen-
sitivity of our own species but, rather, to an inward focus (discussed in Part 3),
and some wolf ancestors became more avoidant of humans rather than tol-
erant of them. Our particular paths brought us together (discussed further
in Chapter 8), whilst others led further apart.
Of course, it is not only dogs that have played an emotional role within
human lives for a large part of our evolutionary past. Many people develop
strong attachment and derive emotional support from many other animals,
not only pets but also wild animals, which share our lives. Perhaps as far
back as over a million years ago, animals came to mean something more to
people than simply being a source of food. The creation of elephant bone
handaxes, for example, suggests that some kind of meaning, or even sym-
bolism, was attached to the use of elephant bones (Lev and Barkai 2015;
Zutovski and Barkai 2015). The appearance and extinction of animals mat-
tered to past humans in emotional terms (Halfon and Barkai 2020). By the
time of archaic humans such as Neanderthals, some animals seem to hold
important meanings. Neanderthals attached signicance to certain birds,
for example, probably using their feathers for adornment (Finlayson et al.
2012; Morin and Laroulandie 2012). People have interacted with many ani-
mals in dierent ways through our evolutionary past, and not simply as a
source of food (Shipman 2010).
Dogs, however, share not only social similarities but also many of our emo-
tional vulnerabilities. Like humans, they are highly sensitive to others’ dis-
tress, aected themselves emotionally and driven to respond. They form
strong attachments and, like humans, thrive in the context of loving and
caring relationships, but are susceptible to a lack of closeness, aection and
touch. They are susceptible to loneliness and sensitive to cruelty. Through
our mutual demonstration and response to vulnerabilities, we develop rela-
tionships based on trust.
Why wolves, and later dogs, came to play such a key role in our lives makes
sense within this larger evolutionary understanding of our shared emo-
tional vulnerabilities.
324 HIDDEN DEPTHS
How did wolves become close to humans?
When we discuss early wolves as ‘hunting aids’, almost like a new type of
tool, we likely miss their signicance in people’s lives and, in turn, some of
the key factors bringing wolves and people closer together.
The relationship between indigenous Australian groups and their dingoes
may give us far more insights into the nature of early ‘domestication’ than
when we look at modern, highly trainable dog breeds. Instead of economic
benets to either, there is evidence here of a genuine drawing together in
emotional terms. Dingoes occupy a space that is neither ‘tame’ nor ‘wild’, fre-
quently living outside of human settlements and not necessarily being fed
by humans, perhaps not too dierent from the relationships early proto-
dogs might have had with Upper Palaeolithic humans. Yet, at the same time,
there is a remarkable intimacy to their relationships to people. Children play
with puppies, and adult dingoes can form close relationships with certain
people. It is certainly not too fanciful to imagine that the route to domes-
tication lay with particularly sensitive people, perhaps isolated or hurt by
trauma, who found friendship, companionship and emotional stability in
similarly sensitive and emotionally vulnerable wolves.
What initially drew wolves closer to humans? Whilst there have been gen-
eral assumptions that domestication began when more tolerant wolves
learnt to scavenge from human settlements (Coppinger and Coppinger
2001), the observation that highly mobile foragers rarely produce anything
like a waste dump calls this into question (Jung and Pörtl 2018). Instead,
it seems most likely that the tamest of the wolves may have begged or
scrounged for food, or lived independently, interacting with humans out of
curiosity and companionship. Packs of Arctic wolves are tolerant of human
proximity and interaction, for example (Smith and Litcheld 2009). As
with dingoes, orphan wolf pups may have been the playthings of chil-
dren, with some adult dogs then remaining attached to human groups.
Wild wolves can form close relationships with people (see Figure 7.11), and
can collaborate in shared goals. However, this relationship takes consider-
able time and eort, and shows little of the ease with which modern dogs
integrate into human life. Wolves or early proto-dogs living within human
groups probably became rather dicult to deal with, or even dangerous, as
they got older. Most adult wolves may have entirely drifted away, or lived on
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 325
the outskirts of human groups, scrounging any food that became available,
drifting back into lives as entirely wild wolves with only a few remaining in
close relationships with humans.
With time, the changing socioecology of those wolves that became more
integrated into human communities, or even simply scrounged for food,
would have inuenced the evolutionary selection pressures that they
experienced (Marshall-Pescini et al. 2017). Being able to tolerate closeness
to humans would have been an advantage, as would a certain openness to
new experiences and new relationships, setting in train a sequence of
genetic changes towards increasing friendliness. These increasingly
friendly wolves would have been better able to develop a new kind of rela-
tionship with humans. Humans, in turn, may have begun to protect and care
for adult wolves and their puppies within human settlements, with their
descendants eventually becoming lineages that were more isolated from
their wild counterparts.
Figure 7.11: Wolves can be socialised to be friendly towards people. Photo-
graph shows a socialised wolf enjoying aectionate contact. Vilmos Vincze
from Hungary, CC BY 2.0, via Wikimedia Commons: https://commons.wiki
media.org/wiki/File:He_can_stand_stroking,_too..._(27205424372).jpg.
326 HIDDEN DEPTHS
The increased sensitivity to social support and emotional vulnerability of
proto-dogs, which comes with increasing friendliness, will have matched
similar vulnerabilities in humans. Proto-dogs could not only have been
able to provide an additional source of aection and stimulation to infants,
and a pleasing sense of reward for nurturance to adults, but also to plug an
emotional gap left through an attachment system highly sensitive to any
deciencies in social surroundings (Kurdek 2008). It is not dicult to see
how such proto-dogs could become an emotional safety net after the emer-
gence of modern humans, who, as we have seen in Chapter 5, were now
increasingly moving between new groups, encountering new people and
living lives that sometimes failed to provide the supportive social relation-
ships they craved. Moreover, as wolves themselves also changed, it may no
longer have been viable emotionally to be a lone wolf, with human com-
panionship preferable to loneliness for wolves isolated from a pack, much
as wolf companionship well have been preferable to loneliness for humans
feeling isolated or lonely themselves. In both species, their recent hypersoci-
ality may have enabled a new kind of relationship, but may also have driven
each towards the other.
Increasingly friendly wolves will have been less dangerous companions,
better able to understand humans, less stressed by human environment,
and more likely to stay for longer within a human group (Morey and Jeger
2015). They may have begun not only to act dierently but to look morpho-
logically distinct, even while still showing some levels of interbreeding with
their wilder relatives. Certainly, the genetic record suggests many thousands
of years of interaction and hybridisation between tame and wild animals.
Sustained domestication, demanding that humans protected wolves from
being driven away or killed for food in times of famine, probably depended
on genuine emotional attachments (Bradshaw 2011). At times and places
where isolation and loneliness (such as from ecological conditions limiting
contacts between human groups), or social stress (such as from more com-
petitive and hierarchical social dynamics), became more pronounced, even
closer attachments may have developed.
With time, proto-dogs will have become ever more emotionally attuned to
humans, to the point at which they could seem almost disturbingly human-
like. For dogs, this would have meant both the potential for strong personal
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 327
bonds with people, but also the possibility of becoming scapegoats for
human relationships, and subject to aggression for the areas in which they
failed to full human expectations. Their capacity to share goals, and con-
tentment with performing roles that were useful, such as hunting, defence
and carrying loads, also allowed them to become a form of technology as
well as a friend.
Rather than being a new technology rst, and friends second, the story of
wolf domestication may have been one in which nurturance and friendship
came rst, and in which emotional vulnerabilities of both species played a
key role.
The journey shared between humans and wolves prompts not only further
questions about that relationship but also leads to reections about our-
selves as supposedly independent from the natural world and the animals
around us. When we consider the closeness of our relationship to dogs, and
their wolf ancestors, we cannot help but reect on the oddity of our human-
focused narrative of human origins. Our social story is almost always taught
as one in which human social relationships are the only ones of signicance.
However, it is clear that, throughout our evolutionary past, our hearts and
minds have been intertwined with those of other animals, of which dogs
are only one example. Children will have played with the young of other
species, and adults will have developed relationships with wild animals
that crossed their paths, or even ones that took residence in their settle-
ments. The relationships we developed with wolves, and the dogs that they
became, are just one example of this intimacy.
Our shared journeys also prompt us to reect on the other pathways, and
evolutionary journeys towards other species which were often equally via-
ble, albeit less intimately connected. We explore one of these alternative
pathways taken by humans in Part 3.
Conclusions
Though we tend to see human origins in a rather individualistic and inde-
pendent way (as discussed in the introduction to this volume), it is clear
that our evolutionary past has been one of a close connection to animals
328 HIDDEN DEPTHS
living around us. This relationship with the natural world is far more inti-
mate than we tend to acknowledge. Ecology, and relationships to other
animals, played an important role in the evolution of human compassion,
as we have discussed in Part 1. However, human closeness and interdepend-
ence with other animals developed even further after 300,000 years ago,
as discussed here. Where our relationship with wolves is concerned, even
the line between ‘human’ and ‘animal’ itself becomes blurred. Members of
this entirely dierent, and only very distantly related, species become our
companions and friends, and even members of our communities. Of all the
animals with which we share our lives, it is the descendants of wolves that
seem to have by far the greatest capacities to aect us emotionally.
The so-called ‘domestication’ of wolves was more likely to have been a pro-
cess in which both humans and ancestral wolves moved physically and emo-
tionally closer to each other, rather than a one-sided imposition by humans
for some economic gain. We often think of the creation of the ‘domestic’ dog
as some kind of human achievement in which dogs have been co-opted
to suit our needs, a little like cleverly adopting a new type of technology.
However, insights from our understanding of the emotional brain, and the
new emotional vulnerabilities that developed during the period 300,000
to 30,000 years ago, suggest, in contrast, that our shared emotional moti-
vations may have had a much more important role to play than we might
imagine, and that our emotional vulnerabilities, rather than our intellect,
may have driven us together.
Key points
• Our evolutionary history is typically represented as one in which humans
were independent from other animals, or even dominated nature. In
reality, our evolutionary past has been about interdependence with the
natural world. Moreover, other animals have played not just an economic
role but important social and emotional roles in our lives.
• Of all the animals with which we interact or share our lives, it is dogs with
which we show the strongest emotional bonds. Dogs can ll a gap in
many of our emotional lives, particularly in modern industrialised con-
texts, providing important emotional support and companionship, as
well as complementing existing human social relationships.
COMPENSATORY ATTACHMENTS AND THE HUMAN-DOG BOND 329
• We have traditionally assumed that the domestication of wolves occurred
due to their functional usefulness as an aid in hunting, in defence or in
carrying loads, and through elevated human ingenuity. However, these
practical functions are largely dependent on specialised breeds or train-
ing, and are likely to have developed long after a close relationship
between people and wolves emerged.
• Wolves and humans share a common background of evolutionary pres-
sures on their emotions, despite the phylogenetic distance which sepa-
rates us. The explanation for an increasing closeness between humans
and wolves, and the so-called ‘domestication’ of the wolf, may lie in
shared emotional needs and vulnerabilities between the two species.
330 HIDDEN DEPTHS
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Part 3
What If? Exploring Dierent
Human Pathways
In this part, we consider alternative pathways in human evolution, and how
we might better understand the dierent humans we might have been. We
focus on dierent adaptive pathways in emotional dispositions, and open
up new possibilities, such as situating Neanderthals as dierent but equal
within our evolutionary story. We also consider how the concept of branch-
ing pathways may help us to move away from progressive narratives and
better understand human origins as a pattern of compromises and vulner-
abilities as well as strengths.
CHAPTER 8
What If? The Evolutionary Basis
for Dierent Pathways
Abstract
All too often, we see our evolutionary past as some inevitable lad-
der of progression. In considering our emotional connections, it is
easy to imagine that the increased external friendliness and sensitiv-
ity seen in ‘modern’ humans represents some progressive or supe-
rior development from a more aggressive past. However, a close
consideration of how external friendliness changes in closely related
species reveals a far more complex picture, with advantages and dis-
advantages to dierent evolutionary pathways, each displaying a dif-
ferent type of prosocial or collaborative behaviour.
There are always many possible evolutionary pathways, aecting
brains, bodies and behaviours. Here, however, we focus on simple
contrasts in the adaptive routes followed within our nearest living
relatives, chimpanzees and bonobos, and those within our closest
friends, wolves and dogs. This brings some insights into how an
increased openness, and the capacities to develop new external
bonds, may have evolved. We reveal that each evolutionary pathway
How to cite this book chapter:
Spikins, P., 2022. Hidden Depths: the origins of human connection. Pp. 343–385. York:
White Rose University Press. DOI: https://doi.org/10.22599/HiddenDepths.i.
License: CC BY-NC 4.0
(Abstract continued on next page)
344 HIDDEN DEPTHS
brought both advantages and disadvantages, depending on context,
rather than any specic pathway being a progression. Our similar
physiological and behavioural adaptations under pressures to be
more tolerant (discussed in Part 2) suggest that the same processes
that occurred in these species also aected humans. An understand-
ing of our evolutionary past as one of dierent alternative trajecto-
ries, and of possibilities and constraints along these, helps to frame
our understanding of the process of human evolution, and the story
of our origins.
(Abstract continued from previous page)
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 345
Introduction
The Road Not Taken
Two roads diverged in a yellow wood,
And sorry I could not travel both
And be one traveler, long I stood
And looked down one as far as I could
…
Two roads diverged in a wood, and I—
I took the one less travelled by,
And that has made all the dierence
Robert Frost, 1916
If we look back on our lives, we can all think of key points at which there
were dierent pathways to take, neither of which at the time seemed better
or worse than the other but from which our choice made a signicant
dierence to the rest of our lives. Robert Frost’s poem ‘The Road Not Taken’
Figure 8.1: Paths diverge in a wood. Photo by Beth Macdonald on Unsplash:
https://unsplash.com/photos/P3rS8J1THi4?utm_source=unsplash&utm
_medium=referral&utm_content=creditShareLink, with unrestricted use.
346 HIDDEN DEPTHS
epitomises some of these moments, in which we stand as if at a forked
point on a path (Figure 8.1), and wonder what each alternative entails. We
often later create a story of why our particular choice was the better one
(Orr 2015).
It would be easy to consider changes that take place along our evolutionary
journey, and particularly with the emergence of modern humans, as a sim-
ple progression towards humans becoming increasingly better, more social,
more sensitive and more collaborative. As we have seen in the introduction
to this volume, we tend to prefer to think of our evolutionary past as a nat-
ural progression towards a better human being (Anderson 2019; Porr and
Matthews 2017; Porr and Matthews 2019). The reality, however, is quite oth-
erwise: our evolution has been a series of alternative pathways, each with
dierent advantages and disadvantages – a far more complex and more
interesting story.
Dierent versions of human, living alongside each other, seem like
something that should be part of science ction. However, we know that
our single existence as the only human species stands out as unusual in our
evolutionary past. Before the last 50,000 years, various dierent humans
were around at the same time, and often in the same regions. Each had fol-
lowed a dierent pathway, with each equally viable at the time.
Often, dierences between species were driven by adaptations to dierent
ecological conditions. The separation of distinct evolutionary pathways at
times of intense environmental unpredictability mark many of the major
changes in human evolution. Moreover, extinctions of human species
closely match climate changes (Raia et al. 2020). As we have discussed in
Part 1, around 2 million years ago members of the genus Homo took a path
towards increasing reliance on hunted meat, and so intense collaboration
and interdependence. However, other hominins, the paranthropines, spe-
cialised more on a plant-based diet, followed a dierent evolutionary path-
way and lived successfully alongside members of the genus Homo for at least
1 million years. Other, equally viable alternatives clearly existed throughout
human evolution. Their brains, bodies and social lives were probably even
stranger than ction. Often, the circumstances that drove dierent adapta-
tions are dicult to determine. The small-brained Homo naledi, for example,
managed to survive perfectly well amongst much larger-brained members
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 347
of the genus Homo, around 250,000 years ago. Areas of their frontal cortex
promoting a complex social understanding may have promoted collabora-
tive behaviours (Holloway et al. 2018), whilst a smaller overall brain than
other species would have been less energetically costly. Under dierent
conditions, it might have been the descendants of these diminutive and
small-brained humans, rather than larger-brained species of Homo, that
took our place today. In short, there have been many dierent pathways in
our evolutionary history. Both our tendencies to want to see our origins as
a single story of progression and a lack of evidence tend to obscure their
existence.
The dierences between other closely related species of highly social ani-
mals can sometimes provide clues as to the dierences between alternative
species of human, not only physically but also in their minds, feelings and
behaviours. Considering non-human animals can also be helpful because,
whilst we nd it hard not to impose a ladder of progression on humans,
we readily understand that the diering adaptations that dierent animals
show to their circumstances are comparatively neither better nor worse. The
primate order is full of such examples. Closely related species can adapt to
behave in quite notably dierent ways in response to subtle changes in their
environments working with their existing evolutionary history. Fat-tailed
dwarf lemurs (Cheirogaleus medius) in Madagascar hibernate to survive
resource shortages, for example, whilst other lemurs live in dierent envi-
ronments or adapt to resource shortages in dierent ways. These paths can
also sometimes converge, not only genetically, when species interbreed,
but also behaviourally. Similar challenges often provoke similar responses
in dierent species, or at least responses that do the same job but in dif-
ferent ways. Diering hormonal changes seems to underlie monogamous
relationships in diering species of lemur as a result of dierent evolution-
ary trajectories, for example (Grebe et al. 2021).
Other examples come from social mammals much more distantly related
to us, as we have seen in Chapters 1, 4 and 5. A fascinating example of sub-
tly diering pathways is provided by African wild dogs (Lycaon pictus) and
grey wolves (Canis lupus). These closely related social canids are both highly
collaborative and share very similar social structures. They hunt together,
raise ospring collaboratively, take risks to defend each other, and share
food. Nonetheless, these two dierent species show subtle dierences that
348 HIDDEN DEPTHS
reect slightly dierent ecological conditions, existing adaptations, or even
just chance. African wild dogs’ social communication focuses particularly on
vocalisations, notably coughs, and on ear movements, whereas wolves are
somewhat more dependent on facial expressions. African wild dogs (as dis-
cussed in Chapter 1) are the most internally socially cohesive of all canids,
supporting the ill and injured. It might be easy to decide that they are the
most social, and most collaborative. However, they are also more territo-
rial and defensive towards outsiders than wolves can be. Neither one nor
the other is ‘better’, or even more social, but these apparently very similar
species are simply collaborative in a dierent way. Whilst we might prefer
a simple story of one species being better than another, other highly social
animals demonstrate that the reality is far more complex.
We particularly struggle to apply these understandings to humans. Often,
we seem only able to think about ladders of progression, and see all humans
that show dierences from ourselves as inferior. Moreover, even though we
know that dierent branches of recent humans have converged, blurring
the distinction between what we think of as our own species and other con-
temporaries, we prefer to focus our attention on ‘our’ ancestors, and elevate
these people above others. Even using the term ‘modern humans’ for people
alive today, and their ancestors evolving in Africa from 300,000 years ago, is
problematic, implying some sense of betterness or progression. Homo sapi-
ens is no better than other, now extinct species of humans (what makes our
species more wise?). We just do not have a widely understood and accepted
term for ourselves that does not imply superiority.
Finds evidencing the increasingly diverse species of humans living after
300,000 years ago, and contemporary with the ancestors of modern humans,
have pushed the beginnings of a reappraisal. One suggestion has been to
see human evolution not as a ladder but as a braided stream (in which all
humans ow or evolve in the same direction along parallel paths). This may
be an improvement on a simple ladder but it is far from without problems.
The reality is that dierent species of humans, like other animals, often adapt
in dierent directions. One fascinating example is the possibility that Nean-
derthals hibernated (Bartsiokas and Arsuaga 2020). This is far from a ridicu-
lous suggestion as Neanderthals may have adapted to resource shortfalls
much like the fat-tailed dwarf lemur. It would, however, be an adaptation
that meant Neanderthals travelled along a notably dierent direction than
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 349
modern humans did, not only in physiology but also, in turn, in its eects
on social behaviour. The possibility raises all kinds of questions around how
hibernation might have been managed within an essentially human society.
It seems more like science ction, yet these very ‘what if’ questions around
adaptations that seem radically unfamiliar are important to ask. Of course,
the idea of branching pathways proposed here, which may sometimes coa-
lesce, and sometimes lead in very dierent but equally viable directions, still
oversimplies what might be better thought of as a multidimensional set of
pathways in which there are dierent domains of adaptation.
However we choose to represent our recent evolutionary trajectory, and
here we think in terms of dierent pathways, the key issue is that of under-
standing dierences without imposing value judgements. This seems to be
a particular challenge with mind or emotion. As we have seen in Chapter 3,
there are real dierences in mind within our populations, all too often seen
as inferiorities, making the challenge of understanding dierences without
a value judgement all the more important. Developing our understanding
of how the emotional dispositions of closely related species can be dierent,
with advantages and disadvantages according to context, and even equally
social or collaborative, albeit in dierent ways, may be one way to help us
rise to these challenges.
Here we draw on our knowledge of dierent branches of emotional
dispositions taken by closely related species to better understand the dif-
ferent pathways that may have been taken by humans in the past. In the
case of non-human animals, it can be easier to acknowledge that subtly
dierent branches may be neither better nor worse, more nor less social,
and nor more or less collaborative than either other, but are rather dier-
ently social or dierently collaborative. Understanding the emotional and
behavioural changes occurring in recent human evolution as being alter-
native pathways aecting emotional connections may help us understand
many of the dierences between archaic humans, such as Neanderthals,
and modern humans.
Each point of divergence along the dierent evolutionary paths oers many
dierent possible directions of travel, which may result in dierent divergent
aspects of brain, biology or behaviour. Here we focus particularly on the dif-
ferent pathways in emotional connections brought about by changes in
350 HIDDEN DEPTHS
tolerance (discussed in Part 2) and their implications for our understanding
of human origins. In Chapter 9, we then apply this understanding to inter-
pretations of our close cousins, Neanderthals.
Alternative evolutionary pathways in other species
How dierent pathways towards or away from external tolerance or ‘friendli-
ness’ play out in closely related species can provide us with useful insights
into the advantages and costs of these alternatives in our own evolution,
and the ecological and social context from which increasing externally
social humans emerged.
In particular, the changes we see in bonobos, in contrast to their close
relatives chimpanzees, and dogs, in contrast to their close relatives wolves,
provide us with potential analogies for similar pathways in our own evolu-
tion. In both cases, we see how, in closely related species, changes in ecology
and demography have driven changes in neuroendocrine function. In each
case, particular social and ecological contexts have driven changes in emo-
tional preferences, capacities and vulnerabilities and enabled new types
of relationships to emerge. Whilst, typically, dogs and bonobos are seen as
‘friendlier’, we argue that neither pathway can easily be identied as better
or worse, or more or less social or collaborative, but, in contrast, demonstrate
subtly dierent adaptations and subtly dierent types of collaboration.
Contrasts in tolerance between chimpanzees and bonobos
Chimpanzees and bonobos are closely related and share many common
characteristics. In fact, many people might struggle to tell them apart. Both
chimpanzees and bonobos share cognitive and emotional capacities to
build strong reciprocal alliances within their group, including to non-kin,
and, in both, there is a certain amount of mobility between groups, mostly
by females. However, there are notable dierences in the levels of aggres-
sion, both within and between groups, as discussed in Chapter 4. Only
bonobos can feel comfortable enough, when meeting other groups, to be
generous to unfamiliar individuals and to share food (Lucchesi et al. 2020).
Dierences in social behaviours between these two species may relate not
only to random genetic drift through the geographic isolation of bonobos
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 351
but also to how their distinctive ecological circumstances inuence the
advantages and disadvantages of dierent social behaviours (Gruber and
Clay 2016). Bonobos benet from living in environments with more stable
and reliable resources than those occupied by most chimpanzees. This has
several implications. Firstly, female bonobos carrying young do not have to
travel as far to nd enough food, and so have more energy to spend in alli-
ance formation, which in turn aects the ability of males to form aggres-
sive alliances. Secondly, more stable and reliable resources lead to reduced
female competition (Clay, Furuichi, and de Waal 2016). Furthermore, less
widely distributed resources also mean that bonobos travel in larger groups,
making it much less likely that any individuals or small groups would be
vulnerable to attack (Furuichi 2009; Wilson et al. 2014). In eect, these sub-
tle dierences mean that female bonobos gain less from competition and
more from collaboration than do female chimpanzees, and that intergroup
aggression is less potentially advantageous. Eectively, larger subgroups
made up of several individuals are not ‘worth’ attacking, given little prob-
ability of success, and stronger female coalitions would also be more likely
to defend against attacks. Both of these factors signicantly reduce the
potential advantages of entering into intergroup conict (Furuichi 2009;
Pandit et al. 2016). Being better at collaboration was more likely to pay o, in
evolutionary terms, for bonobos than it was for chimpanzees. More tolerant
and collaborative encounters also occur where resources are most plentiful
(Lucchesi et al. 2020).
At least partly as a result of dierent ecological contexts, bonobos and chim-
panzees thus followed dierent evolutionary pathways in relation to the
levels of tolerance after their split 1.7 million years ago (Figures 8.2 and 8.3).
As selective pressures to collaborate increase, and pressures to compete
aggressively are reduced, testosterone production in bonobos, in con-
trast to chimpanzees, also begins to decline. As discussed in Chapter 4, the
eect of these variations is seen in dierences in androgen pathways, and
so in reduced aggression and greater potential for intergroup interaction
in bonobos (Hare, Wobber, and Wrangham 2012). However, as we have
seen in Chapter 2, selection pressures acting to change hormone systems
tend to have broad eects. Dierences in testosterone thus also have wide
eects beyond the specic behaviours being selected for (Hare, Wobber,
and Wrangham 2012). Reduced testosterone not only leads to bonobos
352 HIDDEN DEPTHS
Figure 8.2: Ecological contexts inuencing dierences in social behaviour between
chimpanzees and bonobos. Penny Spikins, CC BY-NC 4.0.
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 353
retaining aspects of juvenile behaviour but also aects wider elements of
behaviour, physiology and physical appearance. Bonobos have atter faces,
with reduced brow ridges in comparison to chimpanzees, as well as a more
juvenile face shape. They also have reduced cranial capacity and depigmen-
tation of their lips and tail tuft (Hare 2017). Bonobos are also less aggressive
and more prosocial to non-kin within their group than chimpanzees are
(Tan and Hare 2017), and in a wider range of dierent contexts. Laboratory
experiments have even demonstrated that bonobos are simply more will-
ing to be altruistic to strangers and to give food away accordingly (Tan and
Hare 2013).
Research into bonobo and chimpanzee physiology, neurology and
behaviour continues to reveal potentially important dierences. There are
also some suggestions that changes in other hormones may have had a role
to play in the dierences between chimpanzees and bonobos. Bonobos
show a greater socio-emotional competence, and are more ready to pro-
vide consolation to others in distress (Clay and de Waal 2013), and to oer to
help without it being solicited (Tan, Ariely, and Hare 2017), suggesting that
oxytocin-related empathetic responses to others are more prominent than
in common chimpanzees. That they are more focused on eye contact
Figure 8.3: Male chimpanzee (left), showing marked brow ridge, and
male bonobo (right). Rennett Stowe (chimpanzee image) and natataek
(bonobo image), respectively, CC BY-SA 3.0, via Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Composite_image_of_male
_chimpanzee_(left)_and_male_bonobo_(right).jpg.
354 HIDDEN DEPTHS
than chimpanzees provides further evidence of a more empathetic ori-
entation to their interactions (Hare, Wobber, and Wrangham 2012; Kano,
Hirata, and Call 2015; Stimpson et al. 2016). Indeed, bonobos are so socially
focused that they will even sometimes prefer social interaction and play
rather than a food reward (Warneken 2018). Getting on peacefully with
others seems to have been so important to their survival that motivations
to be sociable and to play can even override more basic motivations to eat.
As research continues, further subtle but important dierences are likely to
come to light.
Dierent evolutionary pathways bring both advantages and disadvan-
tages, and the levels of social tolerance seen in bonobos seems to come
with certain costs. In fact, rather than see bonobos as simply more ‘prosocial’
than chimpanzees, it may be more appropriate to view them as social in
dierent ways. They may be more focused on empathy and reduced compe-
tition, though perhaps less focused on technology and strategic collabora-
tion. Though bonobos are as able to make tools in a laboratory setting, their
use of tools in the wild is far more restricted than that of chimpanzees, for
example. They seem to be too socially focused to be able to nd technologi-
cal solutions to problems. Not only is tool making less evident in bonobos
but collaborative hunting is also much rarer, and much less of their diet is
based on hunted meat than that of chimpanzees (Layton, O’Hara, and Bils-
borough 2012). This may be because collaborative hunting often involves
rather more strategic collaboration than empathetic collaboration. Likewise,
whilst chimpanzees are far more reluctant to give away food than bonobos
are, they are more willing to help with tools (Krupenye, Tan, and Hare 2018).
For bonobos, interactions with tools seem to turn into a social game. Rather
than hand the experimenter a tool that is needed, bonobos are more likely
to tease them (Krupenye, Tan, and Hare 2018).
Increased juvenile behaviour, and increased playfulness, is a common ele-
ment of changes associated with increasing tolerance (Wrangham 2014).
Whilst play behaviour is important in imagination and social bonding, it can
come at the cost of achieving a goal for which technology is required.
Contrasts between two other closely related species, this time not our clos-
est relatives but our closest friends, wolves and dogs, provide us with a further
signicant glimpse into how increasing tolerance may have emerged.
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 355
Dierences in out-group tolerance
– Intergroup encounters are often aggressive in chimpanzees, and are more
passive in bonobos (Sakamaki et al. 2018; Sakamaki et al. 2015).
– Bonobos are known to share food at borders (Fruth and Hohmann 2018).
– Bonobos can be altruistic to strangers (Jingzhi Tan and Hare 2013).
Key ecological/structural dierences
– More stable and reliable resources imply less female competition for
resources in bonobos, added to which, females carrying young have less
far to travel and more time to socialise (Clay, Furuichi, and de Waal 2016).
– Bonobos travel in larger parties. Intergroup conict is thus less eective,
as there are fewer opportunities for picking o individuals or small groups
(Furuichi 2009; Wilson et al. 2014).
Dierences in social structure
– Bonobos have stronger female associations (Furuichi 2011).
– Immigrant females bond rst with females in bonobos (Sakamaki et al.
2015) but with males in chimpanzees (Boesch et al. 2008).
– Bonobos have longer periods of sexual swelling, ovulation is more hidden,
and paternity is more disguised (Gruber, Clay, and Zuberbühler 2010).
– Bonobos respond more readily to the distress of others within their group
(Clay and de Waal 2013).
Physiological dierences
– In bonobos, testosterone stays at similar levels through development, but
it rises in chimpanzees (Hare, Wobber, and Wrangham 2012; Stimpson et al.
2016; Wobber et al. 2010; Wobber et al. 2013).
– Prenatal androgen in bonobos aects the balance of empathising-
systemising (MacLean 2016; MacLean et al. 2017).
– Bonobos show dierences in vasopressin receptor genes, which may be
implicated in dierences in social bonding (Hopkins, Stimpson, and
Sherwood 2017).
– Possible dierences in bonobos related to oxytocin production (Hare and
Woods 2017).
Continued.
Whilst we look like other apes, and share many social and cognitive features,
there are many emotional similarities we share with social carnivores (as
discussed in Chapter 1).
356 HIDDEN DEPTHS
Social cognitive dierences
Social interactions
– Bonobos show a greater socio-emotional competence (Clay and de
Waal 2013).
– Bonobos are prosocial in wider range of dierent contexts than are
chimpanzees (Krupenye, Tan, and Hare 2018).
– Bonobos voluntarily hand over food to an experimenter more readily than
chimpanzees; chimpanzees more readily help with tool use (Krupenye, Tan,
and Hare 2018).
– Bonobos make more eye contact than chimpanzees and their gaze
attention is more drawn to faces compared to the rest of the body than
that of chimpanzees (Kano, Hirata, and Call 2015).
– Bonobos are more motivated (and able) to collaborate than chimpanzees
(Hare et al. 2007).
– There are dierences in neuroanatomical structures between the two
species (Staes et al. 2019) and dierences in socio-emotional circuits
(Issa et al. 2018).
Juvenile behaviour and play
– Bonobos show delay in social inhibition and no reduced tolerance to
others with age, whilst chimpanzees do not (Wobber, Wrangham,
and Hare 2010).
– Bonobos use tools in a play context more readily than chimpanzees
(Gruber, Clay, and Zuberbühler 2010).
– Bonobos will also sometimes prefer social interaction and play rather
than a food reward (Warneken 2018).
Table 8.1: Contrasting behavioural ecology of chimpanzees and bonobos.
Continued.
Contrasts in tolerance between wolves and dogs
In the transition towards becoming dogs, descendants of wolves took a step
further in tolerance than bonobos. They not only became comfortable with
forming bonds with outsiders, even other species (ourselves), but, more
than this, they are driven to do so, and are particularly adept at forming new
emotional bonds.
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 357
As discussed in Chapter 7, wolves and dogs are close relatives. Modern dogs
are relatives of the grey wolf, whose ancestors’ ranges overlapped with early
human populations in Eurasia. Humans will certainly have come into con-
tact with wolves well before ‘domestication’, at the very least as competi-
tors for hunted prey. Carnivore gnawing is common on archaeological sites
where human remains are found, and wolf bones themselves are found on
archaeological sites such as at Boxgrove, England, around 400,000 years ago;
Zhoukoudian in China, dated to 300,000 years ago; and La Lazaret, France,
dated to 150,000 years ago, for example (Serpell 2016). However, evidence
for an unusually close relationship between humans and wolves dates to
after 40,000 years ago, and postdates the arrival of modern humans into
Europe and Asia. At this point, interactions with humans led the ancestors
of grey wolves along two dierent contrasting pathways. Whilst we tend to
focus on the wolf ancestors of modern dogs, it is easy to forget that ‘wild’
wolves did not remain the same but also followed their own path. Whilst
wolves who were attracted to the opportunities provided by human occu-
pation ultimately became the ancestors of domestic dogs, other wolves,
those who avoided humans, led to modern grey wolves.
The close, social interactions that began to emerge between ancestral
dogs and humans were aided by a similarly complex social cognition (see
Chapter 7). Like humans, wolves have complex rules about social behaviour
and have a sense of ‘fair play’, with certain gestures such as play bows, which
are honest signals that they will not harm others (Allen and Beko 2005;
Palagi et al. 2016). Like non-human apes, and humans, wolves seem to have
the rudiments of a theory of mind (Horowitz 2011; Udell, Dorey, and Wynne
2008; Udell, Dorey, and Wynne 2011). Wolves show yawn contagion (one
wolf yawning prompts others to do the same), a sign of empathy (Romero et
al. 2014), and communicate emotions through facial expression. Moreover,
as we have seen in Chapter 1, wolves have high levels of within-group altru-
ism (Jouventin, Christen, and Dobson 2016).
Once again, diering resource availability may have played an important
role in inuencing changes in social behaviours between wild wolves and
ancestral dogs. Wild wolves exploit animal prey that is unpredictable
and concentrated, making them dependent on collaborative hunting to
survive. Wolves living near human settlements, in contrast, will have been
358 HIDDEN DEPTHS
exploiting a more predictable and widely dispersed resource. This favoured
individual exploitation (Marshall-Pescini, Cafazzo, et al. 2017), whether it
took the form of food scavenged from humans, food given to puppies or
favourite adults by humans, or simply that a dierent suite of smaller prey
was found near human settlements.
As a consequence of dierent resource characteristics, wolves living near
human settlements seem to have become much less internally cohesive and
more independent, even before any sustained interaction with humans (see
Figure 8.4).
Typically, we compare wolves to dogs that are domestic pets. However, the
contrast between wolves and modern free-ranging dogs, rather than with
pet dogs (Figure 8.5), provides us with a useful comparison in natural social
behaviour. Whilst wolves share the proceeds of a hunt fairly, provisioning oth-
ers such as pups and lactating females, dogs only rarely share food. Although
pack dogs sometimes hunt, they usually do so individually. Similar contrasts
are seen in raising ospring. Wolves form often lifelong pair bonds, and also
parent collaboratively, with other family members looking after the young
whilst others hunt, and with pups dependent on adults for many months.
Free-ranging dogs, on the other hand, tend to exhibit a very varied mating
system, in which pair bonds are rare. They typically parent their ospring
alone, are not provisioned, and pups have to be independent at a much
earlier age (Marshall-Pescini, Cafazzo, et al. 2017). Free-ranging dogs even
exhibit a novel genetic adaptation to digest starch which is not shared by
wolves (Axelsson et al. 2013). The nature of emotional connections and social
behaviour in wolves and free-ranging dogs has adapted, along each dier-
ent pathway, to the distinctive constraints and opportunities each faced.
We might be forgiven for thinking of free-ranging dogs as less social, or less
collaborative, than wolves since they are far less supportive of others in their
pack. However, this would be far too simple a characterisation. Free-ranging
dogs are much more outwardly tolerant than wolves. A need to toler-
ate proximity to humans may partly inuence changes in pack dynamics
in dogs. Wolves tend to be defensive or, even, aggressive towards other
packs. However, free-ranging dogs are much more tolerant of outsiders. In
some regions, previously pet dogs even commonly join free-ranging packs
(Miklosi 2014). Packs themselves are also dierent in character. Wolf
packs typically comprise a ‘family’ with a breeding pair and their relatives,
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 359
Figure 8.4: Ecological contexts inuencing dierences in social behaviour between
wolves and free-ranging dogs. Penny Spikins, CC BY-NC 4.0.
360 HIDDEN DEPTHS
Figure 8.5: Left: Eurasian Wolf showing long muzzle and short ears. Mas3cf,
CC BY-SA 4.0, via Wikimedia Commons: https://commons.wikimedia.org
/wiki/Canis_lupus#/media/File:Eurasian_wolf.JPG. Right: Free-ranging street
dogs, showing shorter muzzle, atter face and more pronounced ears, as
well as changes in coat colouring. Andrew Currie from Toronto, Canada,
CC BY-SA 2.0, via Wikimedia Commons: https://en.wikipedia.org/wiki
/Free-ranging_dog#/media/File:Street_Dogs.jpg.
and non-kin only join packs when important members have been lost. Free-
ranging dogs, on the other hand, maintain much larger pack sizes, and have
a very uid composition, made up predominantly of non-related animals.
Free-ranging dogs can often form bonds with certain particular humans,
and do so much more frequently and with greater ease than wolves.
Like the changes we have discussed above between chimpanzees and
bonobos, these changes have been brought about by selective pressures
acting on key genes aecting many aspects of biology and behaviour, and
particularly on hormone systems (Dobney and Larson 2006; Trut, Oskina,
and Kharlamova 2009; Wilkins, Wrangham, and Tecumseh Fitch 2014).
Firstly, dogs have experienced a reduction in stress reactivity in compari-
son to wolves through changes in the hypothalamic–pituitary–adrenal
(HPA) axis, adrenal glands and cortisol. In eect, unfamiliar dogs or peo-
ple are simply less scary. Secondly, their abilities to form strong emotional
bonds have changed, with changes in eye gaze-based bonding and oxy-
tocin release (Buttner 2016). Close relationships with people can provoke
a similar response in dogs themselves similar to that ‘warm fuzzy feeling’
we feel in our own human-to-human attachments (Nagasawa et al. 2015).
A further eect of hormonal and wider genetic changes has been on
the physical dierences between wolves and dogs, which are more pro-
nounced than those seen between chimpanzees and bonobos. Modern dog
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 361
‘breeds’ have been selected for certain physical and behavioural features.
However, ancestral dogs, and certain ‘wild’ dogs, show common features in
response to selection for increasing tolerance, notably shorter, atter faces,
reduced teeth size and reduced cranial capacity. Dogs’ greater compliance/
eagerness to please, lower aggression, and heightened social sensitivity may
be brought about through changes in the ventral striatum, with changes in
facial musculature allowing them to be more expressive, particularly when
it comes to expressing vulnerability (Raghanti 2019).
A potentially interesting insight into the social behaviours of incipiently
domesticated dogs comes from dingoes (Figure 8.6), discussed in relation
to domestication in Chapter 7. Dingoes were separated from incipiently
domesticated dogs around 6,000–8,000 years ago, and their group social
behaviour seems to reect that of incipient, rather than fully domesticated,
dogs. In eect, they seem to represent some kind of middle ground between
the outward-focused emotional connections of dogs and the inward-focused
emotional connections of wolves. Rather than the disorganised group social
Figure 8.6: The Australian dingo has anities with both wolves and free-
ranging dogs, and is signicant in sharing some elements of social behav-
iour with both. Jarrod Amoore from Sydney, Australia, derivative work: Mark
Marathon, CC BY 2.0, via Wikimedia Commons: https://commons.wikimedia
.org/wiki/File:Dingo_walking.jpg.
362 HIDDEN DEPTHS
behaviour seen in free-ranging dog packs, dingoes have a monogamous
mating system, and hunt and parent collaboratively, sharing food resources
between themselves in a more wolf-like social manner (Miklosi 2014). They
also tend to defend their territory and their groups, in contrast to the more
exible social group patterns seen in free-ranging dogs. Dingoes are also
far more tolerant of humans than wolves. They maintain eye contact more
than wolves, though less than dogs (Johnston et al. 2017). Whilst showing a
more cohesive internal social structure, dingoes are still able to form close
relationships with humans, albeit being less biddable than fully domesti-
cated dogs. Whilst we may make simple contrasts between chimpanzees
and bonobos, or wolves and dogs, in terms of inward or outward focus of
emotional connections there are clearly shades of adaptation in between,
as well as other possibilities we may not have considered.
As with bonobos, the greater tolerance seen in dogs does appear to have
come at a price, or at least as a compromise (see Table 8.2).
Dogs have also become more socially sensitive and, in turn, more emotion-
ally vulnerable than wolves, largely as a side eect of the neuroendocrine
changes promoting their enhanced tolerance (Miklosi 2014). A narrow
window of reduced fear reactions in wolf pups allows them to orientate
themselves to features of their social and physical environment that are
not dangerous and can be trusted, such as other members of the wolf pack,
though this window closes after two to three weeks. However, in dogs, this
window is expanded by several weeks, providing an opportunity to ‘social-
ise’ with humans and thereafter view them as potential allies. This downside
of this increasingly behavioural plasticity is that it also brings with it a vul-
nerability to the eects of an unsupportive emotional context. Dogs suer
in isolation and crave social contact far more than wolves (Bradshaw 2011;
Serpell 2016). As discussed in Chapter 7, it is not dicult to see how our
human social sensitivities and emotional vulnerabilities share many similari-
ties with those of dogs.
In both chimpanzees/bonobos and wolves/dogs, we can see how subtle
changes in ecology, combined with existing social patterns, can be related
to dierent pathways in emotional connections – towards or away family or
external connections. The dierent pathways may give us unique insights
into diering human emotional connections and social systems in the past.
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 363
Interactions with non-kin and outsiders
– Aggression towards strangers is typical in wolves, although, occasionally, in
exceptional circumstances, non-kin also join packs, such as when packs are
missing key members (Miklosi 2014). Free-ranging dogs have a uid group
membership. The pack may defend itself from other packs. However, out-
siders are often incorporated within packs, and dogs which have previously
been ‘pets’ join free-ranging dog packs (Miklosi 2014).
– Wolf packs are typically made up of a breeding pair and their ospring (a
‘family’), whilst free-ranging dog packs are typically made up of a large
group of non-relatives.
Ecology
– Wolves largely depend on high-risk and unpredictable food resources (hunted
animals), which requires collaboration, whilst free-ranging dogs depend on
widely distributed but more dependable resources from human settlements,
which they typically exploit as individuals. Feral dogs have been known to kill
larger prey. However, they also typically do this as individuals (Miklosi 2014).
– Dogs have evolved an adaptation to digest starch (Axelsson et al. 2013).
– Wolves have a single breeding season, whilst dogs typically breed twice a
year (Miklosi 2014).
Social structure
– Free-ranging dogs tend to live in larger groups than wolves, of varying size
and in multi-male, multi-female communities. Wolves, in contrast, typically
live in groups of around eight individuals, though there can be as many as
40 individuals in a pack. In some ecological conditions, wolves are mostly
lone animals (Miklosi 2014).
– Free-ranging dogs have a uid group membership, made up of non-kin,
whilst wolves’ packs are typically a ‘family’.
– Free-ranging dogs match a linear hierarchy more clearly than wolf family
structures. Whilst aggression is low when food is absent, aggression over
food resources is common in free-ranging dogs (Miklosi 2014). Aliative
behaviours are common in wolves, which also display tactics to reduce
tension through appeasing behaviour (such as looking away from a
threatening approach).
– Wolves develop long-term pair bonds, whilst free-ranging dogs have a very
exible mating system and can display monogamy, polygny, polyandry and
promiscuity (Pal 2003).
Continued.
364 HIDDEN DEPTHS
Social structure
– Wolf pups are reliant on adults of their species for seven to eight months,
dog pups for only up to three months (Miklosi 2014).
Dierences in within-group collaboration
– Wolves share food, parent collaboratively, hunt collaboratively (often taking
risks on behalf of the group), risk injury to defend the pack, provision
pregnant and lactating females, and can provision the ill and injured.
However, these behaviours are typically not seen in free-ranging dog packs
(Miklosi 2014).
– Dingoes, separated from incipiently domesticated dogs around 6,000–
8,000 years ago, have a monogamous mating system, defend territories,
hunt and parent collaboratively, and share food, possibly deriving from an
ancestral wolf-like pattern (Miklosi 2014).
– Conict is observed more frequently in wolves than in free-ranging dogs.
However, conict is more likely to escalate to serious ghting in dogs
(Marshall-Pescini, Cafazzo, et al. 2017).
– Wolves outperform dogs in conspecic cooperation tasks (Marshall-Pescini,
Schwarz, et al. 2017).
– Wolves are more tolerant of proximity during feeding and do not
monopolise food (Marshall-Pescini, Cafazzo, et al. 2017).
Neurophysiology
– Dogs show a delay in the fear-mediating responses as puppies, creating
a longer period when fear responses to novelty are reduced (about three
to 12 weeks), and during which socialisation with humans occurs (Buttner
2016; Topál et al. 2005).
– Dogs show reduced stress reactivity through changes in the SAM
(sympathetic–adrenomedullary) system aecting ‘ight or ght responses’,
and HPA axis aecting adrenal glands and so inuencing the action of
hormones such as glucocorticoids (e.g. cortisol) (Buttner 2016; Saetre
et al. 2004).
– Dogs show an oxytocin-mediated attachment pathway with humans,
engaging in mutual eye gaze from an early age (Buttner 2016; Kaminski et
al. 2009), which stimulates oxytocin responses (Kis, Ciobica, and Topál 2017;
Kis et al. 2014; Kis et al. 2017).
– Dogs’ social focus on humans means that they commonly prefer praise to a
food reward (Cook et al. 2016).
Continued.
Continued.
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 365
Forms of collaboration with humans
Emotional connection
– Dogs (but not wolves) have a long period of potential socialisation with
humans during development, in which their fear response is much reduced
in comparison to similar aged wolf puppies.
– Dogs (but not wolves) can develop a secure attachment to humans, acting
emotionally like an attachment gure (Kurdek 2008), or better understood
as close friend (Miklosi 2014), and providing emotional support (Miller et al.
2009). Humans, likewise, provide emotional support for dogs.
– Wolves take longer to be socialised with humans (though this can be
achieved).
– Dogs have an oxytocin-based response to the human gaze (Kis, Ciobica,
and Topál 2017; Kis et al. 2014; Kis et al. 2017; Thielke and Udell 2017). Din-
goes establish eye contact more than wolves, but less than dogs (Johnston
et al. 2017).
– Dogs approach a novel object in a shorter time than wolves (Marshall-
Pescini, Cafazzo, et al. 2017).
Strategic collaboration
– Wolves and dogs can collaborate with humans by indicating where food is,
and adapting to a more collaborative or competitive human (Heberlein
et al. 2016).
– Dogs are more dependent/pay more attention to humans when moving
together (dogs ‘look back’, whilst wolves do not) (Miklósi et al. 2003).
– Once socialised, wolves are even better at strategic collaboration, and
better able to interpret human social clues (Udell, Dorey, and Wynne 2008).
– Wolves are better able to solve problems independently (Udell 2015).
Table 8.2: Contrasting behavioural ecology of wolves and free-ranging dogs.
Of course, it is easy to oversimplify. There are subtle but important dier-
ences, nonetheless, between changes occurring in wolves/dogs and those
in chimpanzees/bonobos, and this will also have been the case with simi-
lar changes in dierent species of human. Whilst bonobos are principally
less aggressive in both within-group and out-group contexts, dogs have
taken tolerance much further, with a marked openness to new relationships
including with ourselves. They also display more notable novel social and
Continued.
366 HIDDEN DEPTHS
emotional competences. Clearly, there are common directions in changes
in behaviour as a result of pressures towards increasing tolerance and
common genetic changes as a result, but, nonetheless, each species also
follows its own trajectory.
Dierent but equal human evolutionary pathways?
How do contrasts between dierent emotional connections in closely
related chimpanzees/bonobos and wolves/dogs help us to understand dif-
ferent pathways in past humans?
As we have seen in Part 1, humans have been under strong selection pres-
sures to be more internally prosocial from at least 2 million years ago. These
pressures aected the strength of emotional bonds in close-knit groups,
emotionally motivated to care for each other. However, selection pressures
towards wider emotional connections outside the local group, and even
beyond that to imagined beings (Chapter 5), other species (Chapter 7) or
even objects (Chapter 6), appear to have come to the fore in much more
recent human evolution, and most particularly in changes we see occur-
ring after 300,000 years ago. As with chimpanzees/bonobos and wolves/
dogs there are plausible ecological explanations for the dierent pathways
(Spikins et al. 2021). These latter changes share many similarities with those
seen in bonobos and in dogs. Rather than a case of one superior, more intel-
ligent or even more ‘social’ route, dierent pathways are taken by dierent
species under various selection pressures, with each pathway bringing both
advantages and disadvantages. In each contrasting set of pathways we
also see a move towards more infant-like (paedomorphic) features in the
bonobo/dog/modern human sister species, associated with increased toler-
ance, greater intergroup interaction and increased social sensitivity.
These similarities have a genetic component in humans, much as they
do in chimpanzees/bonobos and wolves/dogs (discussed in Chapter 5).
There is some evidence for certain levels of convergent genetic evolution
between humans and bonobos, for example. Genetic changes associated
with increased prosociality are seen in both these species which are absent
from the chimpanzee genome (Theofanopoulou, Andirko, and Boeckx
2018). These changes have been seen in terms of shared adaptive shifts
towards ‘tameness’, ‘friendliness’, ‘domestication’ or ‘self-domestication’
(Hare 2017; Hare, Wobber, and Wrangham 2012; Hare and Woods 2017;
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 367
Theofanopoulou et al. 2017). Similarities to changes occurring in dogs are
even more pronounced. In both humans and dogs, selection for ‘tameness’
has led to reduced stress reactivity brought about through changes in the
HPA axis and reduction in production of stress hormones such as cortisol
(Buttner 2016), whilst novel types of emotional bonding are the result of
changes in oxytocin pathways (Herbeck et al. 2017; Theofanopoulou et al.
2017). This reduced stress reactivity may well play a more important role in
encouraging friendly approach behaviour than any changes in androgens,
particularly since social aggression in humans is more clearly related, in
terms of hormonal reactions, to a complex relationship between testoster-
one and cortisol, rather than to testosterone alone (Montoya et al. 2012).
There are other signicant changes. A willingness to explore new situa-
tions and openness to new relationships, mediated through dopamine,
is also common to both dogs and humans. In both species, this openness is
achieved through an increased sensitivity to social environment, with
changes in similar genes aecting this new ‘hypersociality’ of both species
(Shuldiner et al. 2017). An increase in juvenile-like behaviour in both spe-
cies, associated with more paedomorphic (infant-like) facial anatomy, may
also have led to increased playfulness and, perhaps, imagination (Fuentes
2017; Nowell 2016). These changes also aect eye gaze. Bonobos, for exam-
ple, are more focused on eye contact than chimpanzees are (Kano, Hirata,
and Call 2015), and similar changes may be happening in modern humans,
given our extraordinary sensitivity to facial expressions round the eye
area and the signicance of our movable eyebrows (Godinho, Spikins, and
O’Higgins 2018). In both humans and dogs, changes related to social bond-
ing hormones such as oxytocin may have a particular eect on eye gaze
(Decety 2015; Decety et al. 2012; Kis et al. 2017). Contrasts within human
populations, between individuals with dierent alleles of oxytocin recep-
tor genes, for example, illustrate that higher eective levels of oxytocin are
associated with better abilities to read emotions in others (Dannlowski et
al. 2016). These same alleles are also associated with lower stress in socially
supportive contexts (Chen et al. 2011), and greater tendencies to make
relationships, trust others and form strong bonds, all of which are likely to
be selected for under conditions in which friendliness is selectively advan-
tageous. As we have seen in Chapter 1, oxytocin is important in our close
relationships, creating a sense of warmth, comfort and security (Gilbert
2015a; Gilbert 2015b). These stronger emotional bonds not only function-
ally cement social networks but also buer us from other stresses.
368 HIDDEN DEPTHS
For both humans and dogs, their elevated sensitivity to social environment,
coupled with a greater capacity to form new social bonds, brings both new
vulnerabilities as well as new ways to counteract them. Dogs are extraordi-
narily socially sensitive and have a long period of sensitivity to surround-
ing social cues, accompanied by increased emotional vulnerability to any
lack of socially supported interaction (Miklósi 2014). In humans, as in dogs, a
greater developmental (behavioural) plasticity has led to an enhanced abil-
ity to learn, and an increasing openness (Miklosi 2014). Recent evolution
leading to modern humans, and along a separate pathway to other archaic
species such as Neanderthals or Denisovans, has also contributed to our
heightened neuroplasticity (Sherwood and Gómez-Robles 2017). Both spe-
cies thus benet from an increasingly sensitive and plastic brain, with an
elevated capacity to adapt after birth and outside of that which is under
direct genetic control. These changes bring elevated capacities to learn
from our environment, particularly during development, such as, in the case
of humans, potentially aiding in the acquisition of complex language and
complex cultural norms.
Comparisons with the contrasting pathways taken by chimpanzees and
bonobos, and by wolves and dogs, give us an opportunity to bring into focus
contrasting pathways in humans. It is not dicult to see that, in many ways,
modern humans have taken the more externally tolerant pathway, much
like that taken by bonobos or dogs, whilst other human species followed
a dierent direction (Figure 8.7). Similar changes in emotional dispositions
in modern humans share many similarities with the dierent pathways
recorded in chimpanzees and bonobos, and in wolves and dogs.
To think only of two contrasting pathways is, of course, an oversimplica-
tion. Like the example of dingoes, who share some characteristics with dogs
and others with wolves, there will be pathways in between. Moreover, other
pathways will have led in entirely dierent directions. Nonetheless, the con-
cept of equal but dierent pathways in emotional connections can help us
move beyond ideas of superiority or sameness in interpreting the social
lives and behaviours of our close relatives such as Neanderthals, discussed
in Chapter 9.
Changes in emotional capacities and dispositions at this point of diver-
gence need only to have been subtle to have far-reaching eects on human
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 369
Figure 8.7: Potential changes in emotional dispositions along dierent pathways in human evolution 300,000 to 30,000 years
ago. Penny Spikins, CC BY-NC 4.0.
370 HIDDEN DEPTHS
social relationships. Extending our social network has far-reaching eects,
for example. The number of people you might know and learn from, and
who might be your potentially signicant friends, increases dramatically if
you are able to tolerate and approach unfamiliar individuals. Hill notes that,
in recent hunting and gathering populations, individuals might reason-
ably expect to meet a thousand other people in their lifetime, compared to
around 20 individuals in the lifetime of the chimpanzee (Hill et al. 2014). New
types of mutually generous bonds with distant allies, maintained despite a
gap of time and distance, also provide a remarkable degree of social bu-
ering in times of shortfalls (as discussed in Chapter 5). These alliances can
make a dierence between death and survival. An elevated social sensitiv-
ity also allows cultural and social norms to become easily adopted, and for
cultural ideas to spread, potentially helping innovations to buer the eects
of environmental changes and contributing to a large-scale social harmony.
This elevated sensitivity may even have been instrumental in complex lan-
guage abilities (Thomas and Kirby 2018). There is little doubt that this path,
in the words of Robert Frost, ‘made all the dierence’.
Though we should be wary of making comparisons which are too simplistic,
there is much to learn from these diering pathways in our closest living rela-
tives and our closest friends about our own evolutionary past.
As we have seen in wolves/dogs and in chimpanzees/bonobos, advantages
brought by expanding the scope of social connectivity come with costs and
compromises. The same evolved sensitivities that bring possibilities for high
levels of cultural dynamism, extensive social connection and greater com-
munity resilience, come with elevated emotional needs and sensitivities. We
all feel the costs of these evolved vulnerabilities in various ways.
At an individual level, as we have seen, we need close social support and
emotional connection to thrive, and easily suer in profound ways from
loneliness or social isolation. We are liable to attachment disorders where
genuinely caring relationships are lacking (discussed in Chapter 5) and,
though we may have adapted new types of compensatory attachments
(discussed in Chapters 6 and 7), even as adults we are easily weighed down
by the fears, anxieties and even health eects that a lack of secure attach-
ments bring. We want to belong, to help people, to feel signicant and cared
for. In emotionally supportive contexts, we reach out to help others and are
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 371
sensitive to their feelings. When the structures we need to support our emo-
tional capacities and needs are not there, however, not only do we easily
slip into anxiety or depression but we often take what we can get in terms
of human connection, even if what we turn to hurts ourselves or others.
Sometimes a lack of connection leads us to damage ourselves if we sink into
addictions and, at other times, it can harm others if we lose a sense of reality
and sacrice principles to belong to any group that gives any sense of con-
nection, however unhealthy.
At the level of our societies, our capacity to connect with people who are
unfamiliar can unravel, particularly when we are anxious or fearful. It has
been argued that changes in oxytocin and, with them, propensities not
only to tend but also to defend, might have elevated tendencies to dehu-
manisation (Hare and Woods 2021). However, much of our shared biological
responses to the dierences that can fuel racism or other negative attitudes
are ones which we share with other apes (Sapolsky 2017), as discussed
in Chapter 4. Furthermore, again as seen in Chapter 4, oxytocin can also
prompt befriending, and changes in hormonal responses can have complex
behavioural implications within a cultural context. Rather, tolerance itself, in
bringing with it large-scale connected societies, may be laying the basis for
the level of social interaction that makes dehumanisation an issue, where
previously interactions with others were rare. Simply being prone to a range
of social anxiety, fears and feelings of helplessness and isolation is quite
enough to fuel hatreds. Moreover, our acute social sensitivity means we
are highly liable to ‘follow the crowd’, and our need to belong can make us
override our sensibilities about others’ welfare. As the now-famous experi-
ments of Stanley Milgram and Phillip Zimbardo have demonstrated, com-
pliance with authority, rather than widespread individual evil, can make us
cruel (Zimbardo 2011). Our modern industrialised societies seem some of
the most alienating (Gilbert 2021). All too often, our emotionally vulnerable
brains can be pushed too much to their limits by a lack of connection, and
be so overwhelmed by the challenges of surviving without the right kinds of
connection that there is little space for caring about other people or nature.
We can identify how our emotional vulnerabilities and needs for emotional
connection were adaptive in the past. The evolutionary pathway our species
followed can be judged a ‘successful’ one in terms of survival, expansion and
population numbers. Amongst other changes, elevated tolerance and social
372 HIDDEN DEPTHS
connection provided a buer to resource shortfalls, a means of sustaining
social relationships in the absence of loved ones, and an ability to nd close
friendships outside of human relationships to bolster losses or make us bet-
ter people. That this pathway was ‘successful’ in these terms does not take
away the emotional suering that human sensitivities, needs for connec-
tion and emotional vulnerability sometimes brings, or the potential damage
that humans can inict on themselves or nature. We are, after all, just one
species of many, with emotional responses and behaviours that have been
cobbled together from existing structures along adaptive pathways entail-
ing many compromises.
Implications
A closer look at our evolutionary past reveals a rather dierent story from
the one we are used to in which our species is portrayed as being better
than any others, and perfectly adapted.
We have already seen from Chapter 4 that evolution is far less ordered and
predictable than we might imagine. Species adapt according to immediate
circumstances, regardless of which better options might exist elsewhere in
the longer term. We are lumbered with the back problems that our ancestral
bipedal locomotion brings, for example, as we are too far along this track to
move to something that might place less stress on our lower back, such as
four-legged locomotion. Painful emotions such as shame evolved to moti-
vate us to do what is needed to belong to a group, but they are far from an
ideal means to do so, bringing not only great unhappiness but tendencies
to follow group behaviours no matter the cost, and propensities to depres-
sion (Gilbert 2021). We would not have designed ourselves this way. Added
to which, even when there is selection for one gene that might bring advan-
tageous traits, since many genes are associated with each other, many other
traits come along with the ride. Moreover, the very mutations on which
adaptations depend occur by chance and there are also all kinds of complex
epigenetic factors that inuence which genes are expressed in which par-
ticular contexts. The more deeply we look, the clearer it becomes that we
are far from perfect, or even perfectly adapted. It can seem remarkable that
we manage to negotiate life with our evolved minds, bodies and feelings as
well as we do.
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 373
A new perspective on diering adaptive pathways in tolerance, explored in
this chapter, adds to this picture by bringing into focus not only the advan-
tages but also the compromises that have been brought by changes in
emotional responses.
There are several implications.
Firstly, an understanding that each evolutionary pathway brings compro-
mises aects our interpretations of the archaeological and human evolu-
tionary record. Most obviously, we might revise some of our interpretations
of our closest fossil relatives. An understanding of diering but equal path-
ways in tolerance provides explanations for previously enigmatic aspects of
Neanderthal behaviour, for example. Rather than being inferior, or simply
the same, as our own species, Neanderthals may have had dierent types
of emotional connections, and a dierent focus to collaboration (explored
in Chapter 9). We might also consider some of the many other species of
human from which our pathway has diverged in the past, or who have been
contemporaries. Diminutive species such as Homo naledi, which had small
brains that nonetheless had enlargements in areas associated with social
and emotional processing, might be considered to be following a pathway
with a particular focus on strong emotional connections, for example. We
can and should widen the scope of our interpretations to consider dierent
ways of being emotionally human.
Perhaps even more importantly, there are implications for our understanding
of ourselves. We are naturally able to care about others and to collaborate to
make things better, not only for our kin and friends but also contributing
to the wellbeing of our wider communities or people more generally. Yet
there is a price to pay for these capacities in terms of emotional vulnera-
bilities and sensitivities, and this price is something that can be obscured
by a reassuring narrative of superiority. It is all too easy to plan our lives
and societies around an idea of ourselves as independent, and emotionally
invulnerable, beings. An understanding that our evolutionary history has
been one of compromises, in contrast, highlights the signicance and chal-
lenges of our emotional vulnerabilities. We may be far more willing to give
things up for others than a traditional view of ourselves as independent and
self-oriented beings would suggest, as we have seen through widespread
374 HIDDEN DEPTHS
adherence to constraints on freedoms during the COVID-19 pandemic
across the world. Yet recent times have also demonstrated that we are far
more emotionally vulnerable, profoundly aected by our social and natural
surroundings, prone to depression or anxiety through loneliness and a lack
of belonging, or liable to be inuenced by others, than we like to imagine.
Has our evolutionary story of superiority itself contributed to a disregard
for the emotional costs that come with a lack of connection, perhaps even
in this way adding to a sense of alienation in modern societies? It is dicult
to know for sure. Nonetheless, perhaps a better understanding of our evo-
lutionary history may help us to be more humble about our place in nature,
and to recognise that we are vulnerable to the eects of social isolation or a
lack of social safety. Only by creating supportive emotional connections can
we be what we want to be.
Conclusions
We often think of human evolution as a progressive development of ever
better forms of human, moving towards ourselves as some kind of pinnacle
of evolutionary processes. There were, however, dierent pathways, and dif-
ferent types of human, many of which lie at the limits of our imagination.
Changes in tolerance and emotional connections in recent human evolution
can easily be seen as advancements. However, when we consider how simi-
lar changes in tolerance play out within closely related species, those most
closely related to us (chimpanzees and bonobos) and those most closely
connected to our past ecological niche and present lives (wolves and dogs),
it becomes clear that such changes present both potentials and pitfalls.
Studies of evolutionary changes in external social tolerance in closely
related species cast insight into the types of changes that may have been
taking place within recent human species. Particular ecological and social
contexts may have allowed adaptations leading to external social alliances
to become adaptive. As a result, one evolutionary pathway led to modern
humans with new types of relationships and more extensive social net-
works. It would be too simplistic to see this as simply as an advancement or,
even, as a more prosocial adaptation. Dierent evolutionary directions have
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 375
both advantages and disadvantages, and it may, perhaps, be more appro-
priate to see the alternative pathways lying between early modern humans
and other archaic humans as dierent types of sociality.
By following our particular evolutionary path, we have beneted from an
increased openness to new relationships, reduced stress reactivity in the
presence of unfamiliar others, reduced aggression, and capacities to build
new bonds. However, these adaptations also brought costs in terms of indi-
vidual emotional vulnerabilities and needs for supportive and caring social
contexts. We can easily feel isolated and lack the right kind of emotional
connection, making us prone to depression or anxiety. In modern industri-
alised contexts, where social isolation seems to be particularly widespread,
and where we all too often lack a sense of social safety or relationships
based on trust, these responses are particularly common. Perhaps, if we rec-
ognise that we are not some pinnacle of a process of increasing perfection,
but rather the product of alternative paths, all with compromises, we might
nd it easier to understand why we have both the emotional capacities and
the needs that we do.
If we are honest with ourselves, we would probably admit that our tradi-
tional story of human origins gives us a reassuring sense of entitlement, or
at least a reassurance of things falling into place. A closer consideration
of our evolutionary past reveals far less of a sense of direction, and far
more of a story of the inuence of chance, compromise and vulnerabilities.
This may be a good point in human history to pause and reconsider our
place in the world around this somewhat dierent story.
Key points
• Dierent species of human in the past did not follow a ladder of progres-
sion towards ourselves but travelled along dierent evolutionary path-
ways. For humans, as for other highly social animals, subtle changes in
ecology can create dierent selective pressures aecting tolerance and
the focus of emotional connections.
• Although changes taking place in modern humans, in contrast to archaic
humans, after 300,000 years ago cannot be seen as simply a contrast
376 HIDDEN DEPTHS
between ‘wild’ and ‘tame’, there are, nonetheless, important parallels
with similar changes taking place between both wolves and dogs, and
chimpanzees and bonobos.
• A process of becoming more tolerant is not as simple as that of becom-
ing more social or more collaborative, but rather one of greater social
and emotional sensitivities, greater motivations to explore and to be
playful, and social relationships with a more outward social focus at the
potential expense of within-group collaboration.
WHAT IF? THE EVOLUTIONARY BASIS FOR DIFFERENT PATHWAYS 377
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CHAPTER 9
Reframing Neanderthals
Abstract
Neanderthals have occupied a rather problematic position in our
evolutionary history for many years. Neanderthals and modern
humans share fundamental features of humanity, such as care for
the vulnerable, yet dierences in their use of symbolism, adop-
tion of innovations and intergroup relationships have been hard
to explain. Evidence suggests that Neanderthals lived in small liv-
ing groups with only rare connections to outsiders and high levels
of inbreeding, whilst modern human populations from their rst
arrival in Europe were highly interconnected and maintained con-
nections between communities stretching over large regions. It has
been tempting to interpret these dierences in terms of an inferior
social or intellectual cognition in Neanderthals. Subtle dierences
in emotional dispositions may, however, be a better explanation.
A more inwardly focused or close-knit nature of Neanderthal com-
munities, and a more outwardly focused or approachable nature of
modern humans, can explain previously enigmatic elements of their
archaeological record without recourse to ideas of progression or
advancement.
How to cite this book chapter:
Spikins, P., 2022. Hidden Depths: the origins of human connection. Pp. 387–431. York:
White Rose University Press. DOI: https://doi.org/10.22599/HiddenDepths.j.
License: CC BY-NC 4.0
(Abstract continued on next page)
388 HIDDEN DEPTHS
Our understanding of Neanderthals as displaying subtly dier-
ent emotional dispositions gives us an opportunity to think about
human evolution dierently. Rather than a ladder, or even a braided
stream, here we argue that our evolutionary past is better conceptu-
alised as a series of branching pathways which sometimes rejoin and
sometimes follow dierent directions. Allowing past hominins to be
dierent but equal opens up new lines of interpretation, as well as
challenging us to understand that there is more than one way to be
human.
(Abstract continued from previous page)
REFRAMING NEANDERTHALS 389
Figure 9.1: Recent reconstruction of a Neanderthal woman. Neander-
thals were no less human, yet their physical and behavioural distinctions
challenge our understanding of our relationship to these close cousins.
Neanderthal Saint-Césaire © Sculpture: Elisabeth Daynes/Photo: S. Entres-
sangle. Used with permission.
390 HIDDEN DEPTHS
Introduction
The role of Neanderthals in our evolutionary story has a long and chequered
history from their rst recognition (see Figure 9.1). In 1864, when William
King considered the status of a Neanderthal cranium that had been dis-
covered only a few years earlier in the Neander valley in Germany, he was
challenged by its unusual appearance. Despite being essentially human-
like and possessing a large brain, it was clear that this individual was dis-
tinctly robust, with a large brow ridge and notably long and low brain case
(Figure 9.2). Here was a human, or human-like, being that was disturbingly
dierent. In typical Victorian style, he concluded that this dierence must
relate to some inferiority on a perceived ladder of human progression.
Furthermore, he decided that this being simply must have had an animal,
rather than human, nature. He concluded:
Considering that the Neanderthal skull is eminently simial, both in its
general and particular characters, I feel myself constrained to believe
that the thoughts and desires which once dwelt within it never
soared beyond those of a brute. (King 1864: 96)
Figure 9.2: The cranium (known as Neanderthal 1) from the Neander valley
that was derided as brutish by William King in 1864. Image of cast. Gunnar
Creutz, CC BY-SA 4.0, via Wikimedia Commons: https://commons.wikimedia
.org/wiki/File:Homo_neanderthalensis_(cast_of_Neanderthal_1_skull
cap)_at_G%C3%B6teborgs_Naturhistoriska_Museum_8790.jpg.
REFRAMING NEANDERTHALS 391
We may be alarmed by this ready assumption of brutishness to any dif-
ferent-looking human. However, for more than a century, the unfamiliar
appearance of Neanderthals, coupled with pervasive ideas that our own
species rose above others through some innate superiority, naturally led
to Neanderthals being portrayed as lumbering and brutish (Madison 2020;
McCluskey 2016; Peeters and Zwart 2020). Even as their close-relatedness
to our own species became clear (to the point where we might at most
consider them a subspecies), this relatedness often made them too close
for comfort, leading to continued derision both in public portrayals as well
as academic interpretations. The term ‘Neanderthal’ itself even became an
insult, implying an aggressive and primitive nature.
Attitudes have changed over the last decade. New evidence for Neander-
thal care for illness and injury, the production of art and mortuary practices
have elevated our attitudes to the capacities of our nearest evolutionary
cousins, whilst evidence for interbreeding and a contribution of Neander-
thal DNA to our modern genome has made us increasingly uncomfort-
able about negative portrayals of people who are now seen as close family
(Sykes 2020).
Neanderthals remain a challenge to approach and interpret, even within a
more modern framework. Even though there has been notable interbreed-
ing with our own species, so-called ‘modern’ humans (Hajdinjak et al. 2021;
Lalueza-Fox 2021), Neanderthals have followed a largely dierent path to
that of our own species for most of the last half a million years. They seem
to have beneted from physical adaptations to their particular environments
and ecology that are notably dierent, such as increased levels of brown fat
(Sazzini et al. 2014) and adaptations to a high protein diet (Ben-Dor et al.
2016), and seem to have been better suited to short sprints rather than run-
ning for long periods (Higgins and Ru 2011). They may even have under-
gone something similar to hibernation to escape resource shortages in
winter months (Bartsiokas and Arsuaga 2020). Their brains also developed
dierently (Gunz et al. 2010). As well as evident robusticity and the pres-
ence of a notable brow ridge and dierent cranial shape (see Figure 9.3),
Neanderthals show notable dierences in adult visual cortex (Pearce,
Stringer, and Dunbar 2013), parietal lobes (Pereira-Pedro et al. 2020) and
cerebellum (Kochiyama et al. 2018). The archaeological record shows dier-
ences in technology and in symbolism, and most particularly in patterns of
mobility, interaction and innovation (Spikins, Hitchens, and Neeham 2017).
392 HIDDEN DEPTHS
In trying to explain why the material evidence for Neanderthal behaviour is
dierent from that of the modern humans who replaced them, our atten-
tion has traditionally tended to focus on Neanderthal thinking skills. Par-
ticular attention has been paid to areas of Neanderthal cognition that might
be seen as inferior to that of modern humans, in keeping with our assump-
tion that our species ought to be cleverer than any others. Certainly, there
is some evidence that Neanderthal thought and perception were dierent.
There are a number of regions of modern human brains that seem to dem-
onstrate potentially important dierences from theirs (Bruner 2021). Dier-
ences in the parietal cortex may inuence technical and visual cognition
(Pereira-Pedro et al. 2020), for example, dierences in the cerebellum may
be signicant in organisational skills (Kochiyama et al. 2018), and there may
even be dierences in body cognition (Bruner and Gleeson 2019). The idea
that any dierences, no matter how subtle, should imply human cognitive
superiority seems somehow unsatisfactory, however (Homann et al. 2018;
Langbroek 2012; Zilhão 2014). Moreover, there tends to be little attempt to
focus on where areas of Neanderthal cognition might have been superior.
If we start by assuming that, in terms of their thinking skills, Neanderthals
occupied a lower rung of an evolutionary ladder than modern humans, we
Figure 9.3: Neanderthal (right) and modern human crania (left), showing
distinctive dierences in cranial shape, robusticity, and presence/absence
of a brow ridge. Hairymuseummatt (original photo), DrMikeBaxter (deriv-
ative work), CC BY-SA 2.0, via Wikimedia Commons: https://commons
.wikimedia.org/wiki/File:Sapiens_neanderthal_comparison_en_black
background.png.
REFRAMING NEANDERTHALS 393
tend to nd what we are looking for. We then ascribe behavioural dier-
ences to their supposedly inferior thought.
The only alternative to a view of Neanderthals as necessarily inferior has
tended to be portrayals and interpretations of Neanderthals as the same
as our own species. Certainly, Neanderthals are no less human. Nonethe-
less, seeing Neanderthals as the same is, perhaps, too easy a solution to the
challenge of approaching dierences without assumptions of superiority
and inferiority. Even a recent tendency to move away from an evolutionary
model of a ladder by thinking of human evolution as a braided stream with
dierent species of humans all going in the same direction, is far from per-
fect as it fails to allow for dierent evolutionary directions. No one likes to
be seen as inferior, but equally we might doubt if any Neanderthal meeting
a modern human would want to be seen as just the same.
The problem of how to approach and understand dierences we see in
past species who lived contemporaneously with each other, without
imposing concepts of progression, has become even more pressing in
recent years. Evidence has revealed that the relatively recent evolutionary
past, and particularly the period between 300,000 and 30,000 years ago,
was one in which there were a wealth of dierent human species, from
those who were robust, such as the Denisovans and Neanderthals, to the
tiny Homo oresiensis or Homo luzonensis or small-brained hominins such
as Homo naledi, many of which lived in similar regions at the same time.
It is far too easy to nd ourselves assuming that our ancestors, the taller
and more gracile forms amongst these unusual creatures, were better in
every way, simply because we see ourselves as ‘the survivors’ of this remark-
able proliferation of forms. The real story of what happens is likely to be far
more complex.
Considering emotional dispositions may provide some insights. It may be pos-
sible to nd explanations for dierences in behaviours which do not depend
on inferring that Neanderthals possessed an inferior cognitive capacity.
Dierent types of ‘social’
Can contrasts in emotional dispositions between closely related species today
help us reframe dierences between Neanderthals and our own species?
394 HIDDEN DEPTHS
We have seen how there can be subtle but important contrasts between
quite closely related species that do not clearly divide into ideas of bet-
ter or worse (Chapter 8). Contrasts between wolves and dogs, and those
between chimpanzees and bonobos, are particularly relevant. In con-
trast to free-ranging dogs, wolves are much more willing to share food
amongst the group and to collaborate in care of ospring, as well as to hunt
collaboratively, for example. Free-ranging dogs, in contrast, rarely share
or collaborate in ospring care, and the extent to which they collaborate in
hunting is very limited. Yet, before we simply see wolves as more social or
more collaborative, we must at the same time recognise that free-ranging
dogs are far more open to external connections, and form packs of unre-
lated individuals that contrast with the largely kin groups we see in wolves.
There seems to be a certain inward focus to wolf pack social relationships
that contrasts with the outward focus we see in free-ranging dogs, and
neither can simply be described as more social or more collaborative than
the other. Dierent contrasts, which share some similarities, can also be
drawn between chimpanzees and bonobos. Chimpanzees are far more
eective collaborative hunters, and more prolic users of a wider variety of
tools than bonobos. They cannot be seen as either more collaborative or
more intelligent, however. Bonobos take a more outward focus to their com-
munity social relationships, and have a more intuitive emotional response
to others within their communities.
These dierently social distinctions are apparent between many closely
related species. As we have seen in Chapter 8, African wild dogs and grey
wolves seem very similar and are both highly collaborative, yet communi-
cate their intentions in markedly dierent ways. We should not be surprised
to nd something similar to these subtle but important dierences in types
of social collaboration or communication when we consider dierences
between some closely related human species. Ideas that any one species is
superior to a close relation – more collaborative, more social or more intel-
ligent – tend to be over simplistic.
Dierent evolutionary branches bring diering advantages and disad-
vantages depending on context, and also bring compromises. Changes in
emotional disposition are no dierent. Animals that become more exter-
nally socially tolerant, both under direct human inuence and in the wild,
show a greater social sensitivity and openness to new experiences (and, as
we have seen, dogs have a longer period of openness to new experience
REFRAMING NEANDERTHALS 395
as puppies than do wolves). However, social sensitivity brings with it a
certain neediness. Whilst wolves famously ‘don’t look back’ to their fellows
or plead for support, and tend to solve problems independently, dogs
immediately seek support, particularly from people, and look to others
to how they should behave. Bonobos both reach out to help others much
more willingly than chimpanzees do, and also seem to need and reach
for closeness and aection more often. We cannot simply describe these
dierent types of social behaviour as inferior or superior, or more or less
complex. They are social behaviours that suit dierent contexts, and come
along with compromises.
A better understanding of potential dierences in emotional dispositions
aecting social tolerance, social sensitivity and emotional vulnerability, as
dierences that cannot easily be placed within a ladder of progression, may
help us understand dierent behaviours between dierent human species.
Here, we focus on how insights from understanding dierent pathways
in emotional dispositions may help us to understand archaeological
Contrasts seen when comparing
closely related species
Comparing wolves
and dogs
Comparing
chimpanzees and
bonobos
Diering inward and outward
focus to social relationships
Evident Evident
Diering levels of group
collaboration (hunting, sharing
food, ospring care)
Evident Evident
Diering willingness to include
outsiders
Evident Evident
Diering social sensitivity/
vulnerability
Evident Evident
Diering individual
independence
Evident Unconrmed
Diering facial expressivity Evident Unconrmed
Table 9.1: Key contrasts in emotional dispositions and behaviours between
closely related social species (discussed in more detail in Chapter 8), often
simplied into a generalisation ‘wild’ versus ‘tame’.
396 HIDDEN DEPTHS
evidence for contrasting patterns of social behaviour between communi-
ties of Neanderthals and those of modern humans in Europe. We suggest
that Neanderthals are best seen as dierently emotional, and dierently
social. These dierences, rather than some inferior cognition, can explain
the diering structure of their communities, and dierent behaviours seen
in the archaeological evidence.
Archaeological evidence for contrasting patterns
of intergroup connection between Neanderthals
and modern humans in Europe
Background
It is easy to forget that Neanderthals were a highly successful hominin. They
lived in Europe from around 300,000 years ago, and descended from earlier
species that had been living in the region since at least 1 million years ago.
Whilst there were early incursions of so-called ‘modern’ humans from Africa
into Europe (such as over 200,000 years ago in Greece; Harvati et al. 2019),
their sustained occupation of the region has been quite recent, largely tak-
ing place after 40,000 years ago. Yet, after several thousand years of overlap
and interbreeding, modern humans eventually occupied all of Europe and
displaced Neanderthals.
The similarities between these two populations far exceed any distinctions.
As we have seen in Chapter 2, Neanderthal communities were highly col-
laborative, showing strong altruistic motivations within their own groups,
being willing to care for others for extended periods, and to risk their lives
to bring back food (Spikins et al. 2018). Neanderthals, like modern humans,
were very intelligent, highly socially complex beings who cared deeply for
those around them. Both Neanderthal and modern humans share large
brains, capacities for social complexity, learning and altruism. Furthermore,
any genetic dividing line is far from clear cut, with a notable contribution of
Neanderthal DNA to modern European and Asian populations, for example
(Sankararaman et al. 2016). Many of the traditional interpretations of Nean-
derthals, which portrayed them as having inferior intelligence or being infe-
rior in other ways, such as in their symbolic capacities, have eroded over
recent years (Homann et al. 2018; Langbroek 2012; Zilhão 2014).
REFRAMING NEANDERTHALS 397
Remaining distinctions, which are dicult to explain, are seen in patterns
in the structure of Neanderthal and modern human social networks, social
groups and communities. Explanations for these dierences have tended
to focus on the concept that Neanderthals were socially or cognitively less
competent (see Pearce 2013). Insights into diering emotional dispositions
between closely related species may provide alternative explanations.
Neanderthal community relationships
Like all members of the genus Homo (discussed in Part 1), Neanderthals
were social beings, living in groups and thriving on emotional connection.
When it came to contacts outside of family and living groups, it is clear that
Neanderthal families did not live in isolated social bubbles. It seems reason-
able to talk of Neanderthal communities, stretching beyond the connes of
a single local living group (Sykes 2012). Similar artefacts found across large
regions demonstrate that Neanderthals within some regions had a shared
understanding of how certain things should be made. Regional styles are
identied in Middle Palaeolithic lithic technology, for example (Ruebens
2013), as well in mortuary practices (Pettitt 2010). Individuals must have
moved between groups at certain times.
Nonetheless, though there were some connections between Neanderthal
groups, the scale of everyday social life seems to be small. Living groups
seem to have been largely small and kin-based. At El Sidrón, in northern
Spain, the skeletal remains of several individuals who were presumably a
single group, victims of an unfortunate rock fall, were recovered. The group
consisted of 13 Neanderthals: seven adults, three adolescents, two juveniles
and one infant, of whom three of the adults were brothers, whilst the adult
females were unrelated (Lalueza-Fox et al. 2011; Ríos et al. 2019). Intrasite
spatial patterns also suggest that a small group of this size may have been
typical (Spikins, Hitchens, and Needham 2017).
Archaeological evidence also suggests that interactions between groups,
whilst they must have occurred occasionally to maintain mating networks,
were infrequent. In many regions, raw materials used for making int tools
are moving only within the expected ‘home range’ (the area in which any
single group might have travelled to nd enough food). For example, raw
398 HIDDEN DEPTHS
materials within sites in the Southern Massif Central in France come pre-
dominantly from within the region itself, suggesting that there was little
travel beyond this region (Fernandes, Raynal, and Moncel 2008). Raw mate-
rials for int tools typically come from the most local source possible in
this region – such as within ve kilometres (Fernandes, Raynal, and Moncel
2008), with even only 20 kilometres away being exceptional.
Moncel commented:
The data suggest highly mobile human groups, travelling in small
territories on plateaus and valleys, along the Rhône corridor for daily
subsistence. There is no evidence of human travel into the Massif
Central Mountains to the west to collect raw materials; in fact any
geographical obstacle appears to have stopped human movements
along the south-eastern border of the Massif Central. (2011: 261)
This is not unusual for many European Middle Palaeolithic sites, such as in
northern Italy (Spinapolice 2012) and the Swabian Alb (Conard, Bolus, and
Münzel 2012), where raw materials predominantly come from within 10 kilo-
metres. Across the whole of Europe, raw material movements are commonly
small-scale, with those of more than 100 kilometres being exceptional
(Féblot-Augustins 1993; Féblot-Augustins 1999; Féblot-Augustins 2009).
Raw materials are sometimes transported in a notable quantity from beyond
what might be a typical home range. However, this only seems to occur
where it seems to be a matter of necessity. In southern Italy, for example,
the majority of int raw material used in some of the sites in the Salento
region comes from about 100–150 kilometres to the north. However, in
this case, local raw materials are particularly poor quality and would have
been dicult to use (Spinapolice 2012). Regular movements between home
ranges may have been possible when required, without necessarily being a
welcome pleasure.
There are frequent instances where a few examples of distant materials
are recovered from Middle Palaeolithic sites, providing evidence of inter-
group interactions or movements. For example, at Lezetxiki, in northern
Spain, a marine shell that had travelled over 500 kilometres was recovered
from Middle Palaeolithic deposits dating to 55,000–48,000bp (Arrizabalaga
2009), seemingly as a ‘one o’ transport (Spikins, Hitchens, and Needham
REFRAMING NEANDERTHALS 399
2017). A few well-used artefacts found at Cap Grand in south-west France
had travelled over 400 kilometres (Slimak and Giraud 2007). Furthermore,
int from distant raw material outcrops has been found in certain Middle
Palaeolithic assemblages at Amud cave in Israel, even though there seems
to be no systematic exploitation of these raw materials (Ekshtain et al. 2017:
207). However, these occasional longer-distance movements t within what
we expect through personal transport (Kuhn 2012), that is, tools or raw mate-
rials that someone took with them, perhaps over a long period of time, and
which ended up moving a longer distance from the source. The evidence for
longer-distance movements outside of a group’s typical range are consist-
ent with what we might expect when external social connections were not
common (Djindjian 2012). Such movements are not at all surprising, poten-
tially occurring within mating networks and perhaps only as frequently, as
we see in other social animals such as chimpanzees or bonobos. What we
lack is any good evidence for frequent social interaction between groups.
There even seems to be marked constraints on signicant movements
across dierent home ranges in some regions. In the Middle Palaeolithic of
the Levant, detailed studies of the transport of int materials to the site
of ’Ein Qashish suggest potential borders between groups where resources
remain unexploited (Ekshtain et al. 2014; Ekshtain et al. 2017; Hovers 2018).
This ‘gap’ in raw material procurement regions between what were probably
neighbouring home ranges of dierent Neanderthal groups suggests that
separate groups largely kept to the ‘their side’ of the border.
Genetic evidence adds to this picture of restricted intergroup movement.
At El Sidrón, intergroup movements, such as they were, may have been
constrained to a patrilocal pattern in which related males stayed in the
group and females moved at maturity (Lalueza-Fox et al. 2011; Ríos et al.
2019). Other genetic evidence from the Altai Mountains in Siberia also sup-
ports the notion of females moving between groups whilst males stayed
within their local group (Gibbons 2021). This would suggest that it was
females who were creating patterns of long-distance transport, and main-
taining cultural contacts. There is little to no archaeological evidence for
sustained gatherings of communities any larger than local family or living
groups (Spikins, Hitchens, and Needham 2017). Limited social connec-
tions are also associated with high levels of inbreeding. Half-sibling mat-
ings were common in the ancestry of the Altai individual (Prüfer et al. 2014),
400 HIDDEN DEPTHS
for example. Moreover, levels of developmental abnormalities, such as cleft
palate at El Sidrón (Ríos et al. 2015), are higher than those typically seen in
social primates (Trinkaus 2018), and may even have been a contributing fac-
tor to Neanderthal demise (Ríos et al. 2019).
A rather close-knit focus to Neanderthal social life may explain characteris-
tics of their art. Neanderthals were clearly capable of symbolism, creating
a range of symbolic material culture, from using decorative eagle features
(Finlayson et al. 2012; Peresani et al. 2011) to cave art engravings (Rodríguez-
Vidal et al. 2014). We see, as well, paintings and hand prints (Aubert, Brumm,
and Huntley 2018; Homann et al. 2018), incised and painted shells (Pere-
sani et al. 2013) and even a facial representation (Marquet and Lorblanchet
2003), many of which clearly predate the arrival of moderns who cannot
simply have been the inspiration for such creativity. Pigment use dates back
to at least 200,000 years ago and is widespread, probably as a form of body
decoration (Roebroeks et al. 2012), as do mortuary practices (Majkić et al.
2017; Pettitt 2011). However, Neanderthal art and symbolism is locally dis-
tinctive and there is not one but many varied forms of personal expression
(see Figures 9.3 (Radovčić et al. 2015) and 9.4 (Rodríguez-Vidal et al. 2014)).
In many cases, each example is entirely unique. It seems likely that the scale
of Neanderthal social relationships had an impact on their style of cultural
interactions, leading to a certain independence of local art styles rather than
shared regional norms of expression.
Modern human communities replacing Neanderthals in Europe were simi-
lar to them in many ways, including nely tuned exploitation of their envi-
ronments, care for the ill and injured, complex cultures and sophisticated
technologies. However, their community connections were distinctly dier-
ent in scale.
Modern human communities
We should be cautious of oversimplifying these dierent populations, par-
ticularly given variability in both Neanderthal and modern human occupa-
tion over vast realms of time and space. Nonetheless, it seems that the social
lives of modern humans in Europe were distinctively dierent from those of
Neanderthals in certain important characteristics.
REFRAMING NEANDERTHALS 401
Figure 9.4: White-tailed eagle talons from the Krapina, dating to approxi-
mately 130,000 years ago. These talons are particularly signicant as
they seem to have been worn suspended as jewellery. Radovčić, Sršen,
Radovčić, and Frayer. 2015. ‘Evidence for Neandertal Jewelry: Modied
White-Tailed Eagle Claws at Krapina.’ PLoS ONE 10 (3): e0119802. DOI:
https://dx.doi.org/10.1371/journal.pone.0119802. Luka Mjeda, Zagreb,
CC BY 4.0, via Wikimedia Commons: https://commons.wikimedia.org/wiki
/File:Neandertal_Jewelry_(from_PLoS).jpg.
402 HIDDEN DEPTHS
Figure 9.5: Neanderthal engraving in cross hatch shape found in Gor-
ham’s Cave, Gibraltar. AquilaGib (Stewart Finlayson, Gibraltar Museum),
CC BY-SA 4.0, via Wikimedia Commons: https://commons.wikimedia.org
/wiki/File:Neanderthal_Engraving_(Gorham%27s_Cave_Gibraltar).jpg.
From the rst arrival of Upper Palaeolithic populations into and across
Europe, their community relationships seem to be markedly dierent from
those of the Neanderthals (see Table 9.1). They spread remarkably quickly
into the region then occupied by Neanderthals around 40,000 years ago
(Hoecker 2009), soon reaching regions as far ung from their eastern entry
through the Levant as southern Spain (Cortés-Sánchez et al. 2019) and Sibe-
ria (Douka et al. 2019). It is tempting to conclude that these populations
were simply cleverer than previous ones, or more adaptable, but that many
dispersals also failed, or were so risky as to be irrational rather than clever,
argues that other distinctions were important. New motivations, and new
types of social connection, are likely to have played an important role in
motivations for this new level of mobility (see Spikins 2015).
REFRAMING NEANDERTHALS 403
The movements of raw materials and spread of art and personal ornamenta-
tion suggest that new large-scale alliances appeared quickly. From the very
start of the occupation, identical Aurignacian beads were found over large
regions and were transported across large distances along networks (Pettitt
2014; Vanhaeren and d’Errico 2006), for example. Marine shells commonly
travelled over 200 kilometres, and some travelled over 1,000 kilometres.
Unusual examples even include those that are made of human teeth, and
are much worn, suggesting a close relationship with someone was being
marked out and remembered (Spikins 2015a; White 2007). Large regions
sharing similar styles of beads, and with transfers of beads across them, also
suggest that people were re-enforcing a concept of ‘us’ that included whole
communities (Vanhaeren and d’Errico 2006), much like those seen in hunter-
gatherer ethnic communities today (Layton, O’Hara, and Bilsborough 2012).
Indirect procurement, i.e. the deliberate travel over some distance typically
outside of the home range in order to pick up raw materials for later use,
or exchange of materials between groups, appears to have been common
(Tomasso and Porraz 2016). Raw materials are typically brought from out-
side the area of a typical home range, with the transport of materials over
100 kilometres being common (Féblot-Augustins 2009). In some Gravettian
sites, for example, more than 50% of the raw material comes from over 100
kilometres (Féblot-Augustins 2009). A drawing of a seal on a shale plaquette
from the Late Magdalenian at Andernach-Martinsburg, found with marine
shells and a whale bone fragment, over 1,000 kilometres from the coast, was
probably made by an individual who had travelled that distance (Langley
and Street 2013).
Genetic evidence also shows frequent movements and interaction between
groups, beyond what would be purely functional (Fu et al. 2016). The
genome sequences of Sunghir burials II, III and IV on the Russian Plain, dat-
ing to around 34,000 years ago, indicate extensive connections between
groups and exogamous mating practices (Sikora et al. 2017).
There is even remarkable evidence from northern Spain for community
aggregations. Collaborative hunting of mammoths at large mammoth
megasites, such as Předmostí in the Czech Republic (with a minimum of 105
mammoths, dated to 26,000 years ago; Shipman 2015), is also likely to have
needed collaborations between groups. Towards the end of the period at
404 HIDDEN DEPTHS
Dierences
European Neanderthals Upper Palaeolithic modern
humans in Europe
Population
spread and
migration
Archaeological evidence
for slow spread of popula-
tions, typically in response to
ecological changes and not
crossing major ecological barri-
ers (e.g. the Straits of Gibraltar)
(Spikins 2015b)
Genetic and archaeological
evidence for rapid popula-
tion migration into new
areas, and against ecologi-
cal barriers (Cortés-Sánchez
et al. 2019; Hoecker 2009;
Hublin 2015)
Mating networks Genetic evidence for limited
mating networks. Half-sibling
matings common (Prüfer et al.
2014). High rates of inbreeding
(Sánchez-Quinto and Lalueza-
Fox 2015, Gibbons 2021), lead-
ing to high rates of develop-
mental abnormalities (Trinkaus
2018), such as cleft palate at El
Sidrón (Luis Ríos et al. 2015).
Mating networks large
scale, and similar to modern
hunter-gatherers (Fu et al.
2016; Pearce 2013)
Scale of move-
ments within
foraging areas
Raw material procurement:
Raw materials typically trans-
ported within constrained
territories (Djindjian 2012) (for
example within the Vercors
basin) (Fernandes, Raynal, and
Moncel 2008; Pearce 2013)
Isotope evidence:
Short distances travelled over
lifetime: example of Lakonis,
Greece (Richards et al. 2008)
Raw material procurement:
Apparently very large forag-
ing areas (at least up to last
glacial maximum; Djindjian
2012) and high mobility
within these areas
Frequency of
long-distance
movements
Regionally longer-distance
procurement rare, and in
case of need (such as lithics
imported into southern Italy)
(Spinapolice 2012)
Regionally indirect
procurement (to select
optimal-quality int)
probably common
(Tomasso and Porraz 2016)
Continued.
REFRAMING NEANDERTHALS 405
Dierences
European Neanderthals Upper Palaeolithic modern
humans in Europe
Over large areas long-distance
movements rare, and limited to
certain contexts (e.g. the East
European Plain) (Féblot-Augus-
tins 1993; Féblot-Augustins
1999; Féblot-Augustins 2009)
Over large areas long-
distance movements are
common (Féblot-Augustins
1993; Féblot-Augustins
1999; Féblot-Augustins
2009). Whilst these may be
a result of transfers of mate-
rials and nished products,
there is also evidence of
movement of individuals
(Langley and Street 2013)
Use of art objects
within social
networks
Symbolism of many dierent
forms, including cave art, but
remains local
Material and nished
personal ornaments in the
early Upper Palaeolithic
transported over long
distances (marine shells or
mammoth ivory typically
travel over 200 kilometres,
sometimes over 1000
kilometres)
Cultural resil-
ience (mainte-
nance of local
cultural styles)
Highly conservative art
styles over large regions
Table 9.2: Archaeological and related evidence for similarities and
dierences between Neanderthal and modern human large-scale social
interactions.
the Magdalenian site of Altamira in northern Spain, many design elements
were represented on engraved and decorated bone and antler artefacts
that were not found together in surrounding sites (Conkey et al. 1980). Con-
key concluded that this was an aggregation site, to which many surround-
ing groups, each with their separate distinctive design styles, had travelled
(Conkey et al. 1980). With no particular reason for any concentration of
Continued.
406 HIDDEN DEPTHS
resources at this site, this aggregation seems to have been fullling a social
need, rather than an immediately practical one.
These social alliances seem to have played a key role in survival at times of
resource shortfall, much as they do in modern hunting and gathering con-
texts (Whallon 2006).
There are certainly important survival advantages to regional connection
and collaboration. Intergroup collaboration can make exploiting certain
resources possible. Certain ethnographically and archaeologically docu-
mented populations join together to hunt particularly large or concentrated
resources that might otherwise have been risky or impossible to hunt alone.
The collaborative hunting of whales is a well-known case, as such hunt-
ing is dicult, if not impossible, without large numbers of people working
together (Reeves and Smith 2006). Groups of Inuit coming together for col-
laborative whaling activities have been recorded from the late 18th cen-
tury (see Figure 9.5). Hunting of bowhead whales has even been shown to
be a major factor in the signicant population expansion of Thule culture
around ad 1000 (Wenzel 2009). Collaborative whale hunting is also known
ethnographically elsewhere. Collaborative sperm whale hunters in Indone-
sia bring home more resources through their collaboration than they could
through more individual shing (Alvard and Nolin 2002), for example.
On the level of individuals, the most famous example of the survival sig-
nicance of distant friendships is that of the Ju/’hoansi xaro network. The
xaro is a network of gift-giving, visits and mutual friendships that buers
human communities from the eects of shortfalls and famines. Members
of Ju/’-hoansi bands each forge alliances with non-kin or distantly related
kin in other bands, giving them carefully made gifts and visiting them. It is
these allies whom they turn to in times of local crisis (Wiessner 2002a; Wiess-
ner 2002b). When food shortages following high winds destroyed much of
the mongongo nuts in /Xai/xai province, for example, half of the population
moved in with distant exchange partners, and would not have survived if
this social support was not possible (Wiessner 2002a). These external allies
can sometimes make a dierence to survival, with such alliances even a mat-
ter of life and death.
Connected regional communities also favour survival in other ways.
The best-studied eect of the emergence of social networks has been in
REFRAMING NEANDERTHALS 407
allowing the spread of new ideas and innovations (Apicella et al. 2012; Foga-
rty 2018). Although they might live in small social groups, any individual in
a similar hunting and gathering context is likely to interact with over a thou-
sand other people over the course of their lifetime. Hill notes, for example,
that, amongst the Hadza and the Aché, men are likely to have learnt how to
produce tools from over 300 other individuals (Hill et al. 2014). An aware-
ness of what is happening elsewhere, and an ability to pick up new ideas,
can be important in allowing populations to adapt quickly to environmental
changes (Derex, Perreault, and Boyd 2018; Foley and Gamble 2009; Muth-
ukrishna and Henrich 2016). Connections thus foster rapid adaptability.
It would be easy to frame the contrast in communities as one between
simple and complex, or even primitive and advanced, particularly since we
associate the extensive social networks of the Upper Palaeolithic with the
survival advantages of providing a social buer for resource shortfalls. How-
ever, a closer consideration shows that, by focusing on the role of emotional
dispositions in social tolerance, we reveal that equal but dierent may be a
better way to understand such contrasts.
The structure of social networks and contrasting emotional
dispositions in social tolerance
From our privileged position as the apparent survivors, it is easy to see
networks of allies across connected Upper Palaeolithic communities as a
sign of superiority. These populations appear socially and cognitively more
complex, and better able to negotiate collaborations than Neanderthals.
However, a focus on the economics of resilience to resource shortfalls may
be hindering our understanding that the underlying mechanisms allow-
ing their creation are not calculated or cognitive but emotional. Moreover,
those capacities that allow the creation and maintenance of large-scale
connections also carry costs. Considering the emotional basis underlying
community connections in Neanderthals and modern humans allows a
reframing away from inferior or superior.
The creation and maintenance of the regional communities and social net-
works seen in modern humans depend on a high level of social tolerance,
on a strong drive to connect and, above all, on an individual emotional vul-
nerability that is both a strength and a weakness of these interconnected
communities.
408 HIDDEN DEPTHS
When we look in more depth at what drives regional collaborations in mod-
ern hunter-gatherers, we reveal the signicance of emotional connections,
rather than logical or calculated arrangements. Mutual generosity and
trust, rather than calculated collaboration, is the basis for the collaborations
to exploit resources. The coastal-living Yamana of Tierra del Fuego devel-
oped mutually generous alliances in order to exploit periodically beached
whales, for example, which were a cause for many celebrations and shared
rituals, such as the chiexaus and kina initiations (Chapman 1997; McEwan,
Borrero, and Prieto 2014). Smoke signals were sent to invite as many other
groups as possible to join in the feast, with this mutual give and take main-
tained by trust that this goodwill would be returned in the future (Gusinde
1986; Santos et al. 2015).
Where individual networks of friendships with distant allies are concerned,
similar emotional motivations based on social tolerance, mutual generosity
and trust are also key. The xaro has been seen in terms of networks of obli-
gations, almost like a contract, but this would be a misunderstanding of the
emotions underlying such networks. It is clear that people look forward to
seeing xaro partners, and nd preparing gifts a pleasure rather than a chore
(Wiessner 2002a). Xaro partners ‘hold each other in their hearts’ (Wiessner
2002a: 27). Moreover, evening talk around campres is not just about those
people present at the time but also involves stories told about ties to distant
people and remembered gatherings in the past (Wiessner 2014).
The value of connected communities lies not just in knowing a lot of people,
as we might consider a social network today, but in caring about distant
friends who also care about you. Migliano et al. demonstrated, for exam-
ple, that networks amongst the Agta and Bayaka are made up of close
relationships maintained over lifetimes with a few individuals (Migliano et
al. 2016). In viewing networks of social alliances as economic systems, we
can easily lose sight of the social and emotional capacities and motivations
which they depend on. Yet it is clear that neither systems of obligation,
nor simple agreements, work to ensure support in times of need. Relation-
ships based on ‘needs-based transfers’ (responding to the vulnerability of
those in need), rather than on systems of obligations, are those that ensure
survival (Campenni, Cronk, and Aktipis 2017; Cronk et al. 2017; Smith et al.
2019). Strong emotional drives to make close friends outside our kin are
REFRAMING NEANDERTHALS 409
motivators of human behaviour that provide mutual support everywhere
(Cronk et al. 2017).
Networks of trusting relationships and close friendships are built on both a
high level of social tolerance towards strangers, and also on certain social
needs and emotional vulnerabilities to loneliness or lack of belonging. This
individual vulnerability is also important to how social alliance networks are
maintained as, without a strong emotional need to sustain and extend net-
works of social support to avoid a sense of isolation or loneliness, connec-
tions would fall out of use. Even when food supplies and the emergence of a
cash economy made the Ju/’hoansi xaro network unnecessary, networks of
social ties with distant friends were still kept up, even though fewer partners
are typically involved (an average of seven rather than 15). These distant
allies were socially and emotionally necessary, even if they did not perform
a practical economic function (McCall 2000; Wiessner 2002a). Maintaining
such relationships involves eort. The Jo-huansi spent about a third of the
year visiting close friends in distant camps, and about 75 to 80 days making
gifts to give them (Wiessner 2002a).
Opportunities to gather together are also important. A universal feature
of modern hunter-gatherers, in all dierent environments, is that small
living groups or bands will periodically join together as larger communi-
ties, or aggregations (Conkey et al. 1980; Kelly 2013). These gatherings are
important in ensuring the sustainability of mating networks. However, they
also full a need to reconnect with old friends and develop new emotional
connections, as well as for people to feel part of a larger community. Peri-
odic gatherings seem to be as much about a human emotional need for
meaningful social connection as they are a functional necessity. The times
and places of aggregations usually coincide with a seasonal concentration
of resources, but also provide an opportunity for important rituals to take
place. Even where resources are more predictable and the risk of shortfalls
less acute, alliances are still maintained.
Gatherings in modern ethnographically documented hunter-gatherers
occurred even in the most dicult of conditions and despite notable
costs. Gathering together is something people need to do. Even in the
extraordinarily harsh conditions of the Western desert of Australia, in which
410 HIDDEN DEPTHS
population densities were as low as one person per 300km2, the Martu still
put considerable eort into coming together at aggregations, for example.
In this highly arid region, it was typical to travel over 200 kilometres at least
once a year to attend social gatherings (McDonald and Veth 2012). A ‘tjabal’
(the multitude) took place once or twice a year, particularly in winter, when
seeds were abundant, and around reliable water sources in summer, for
example (McDonald and Veth 2012). These social gatherings did not have
a direct practical function but were nonetheless seen as vital. They were
the focus for rituals, exchanges of goods and marriage arrangements, and
general socialising that continued as long as resources and water allowed
(typically a few weeks to a couple of months; McDonald and Veth 2012: 93).
Moreover, these gatherings were also about extending friendships rather
than reinforcing existing communities. There were no clear limits to the
community who were allowed to attend and the attendance at aggrega-
tions amongst the Martu was exible, sometimes including dierent dialect
units and never the same set of individuals as previously. Hunter-gatherers
commonly adapt their mobility patterns to maintain contact, even where
this is costly (Grove 2018).
Oral histories within modern ethnographically documented groups
conrm that it is emotional needs that underlie social connections. Gath-
erings and shared ceremonies are essential to maintaining emotional
resilience and wellbeing. Coming together as a group and meeting distant
friends provided a marked buer to depression, anxiety and suicide (Danto
and Walsh 2017).
Informants amongst the Cree commented:
‘It was always through ceremonies and people talking to each other
– Everybody would migrate as a whole, come from dierent places to
get that and go back. You see … that was our form of communication
and life. And we used ceremonies to do that.’ ‘It’s not just something
to talk about. It’s a way of life, you know…’ ‘those are the things that
made our people strong: ceremonies’. (Danto and Walsh 2017: 723)
Collaborative social networks can only be maintained through strong emo-
tional desires to maintain friendships, and by extending genuine emotional
motivations to help others’ wellbeing well beyond kin and co-residents
(Cronk et al. 2017; Fowler and Christakis 2010). Being socially astute or clever
REFRAMING NEANDERTHALS 411
is not enough. Far from being a product of calculated strategy or cogni-
tive complexity, connected social networks depend on emotional motiva-
tions. They depend on strong emotional needs and motivations to seek out
friendships and to avoid loneliness or lack of belonging. Only these strong
emotional motivations maintain networks of friendships in times of plenty,
so that they also exist at times of need.
We have always assumed that large-scale regional connections in Upper
Palaeolithic communities were brought about through new superior social
capacities, and that ‘we’ modern humans are simply cleverer and more
social than our predecessors. However, it is much more likely that new sen-
sitivities, emotional vulnerabilities and new elevated needs for widespread
emotional connections lay at the root of these new connected societies.
Rather than a change in cognition, it is far more probable that a change
in emotional dispositions towards an external focused tolerance, bringing
with it individual emotional vulnerability, needs for connection and belong-
ing, and tendencies to loneliness, explains the creation of Upper Palaeolithic
social networks.
Rather than a concept of ‘better’ and more social Upper Palaeolithic com-
munities, we might perhaps see the dierences in behaviours observed in
the archaeological record in a new light, reecting the advantages and dis-
advantages of alternative evolutionary trajectories in the focus of emotional
connections. As we have seen in Chapter 8, a more outward or inward emo-
tional focus is suited to dierent contexts. Despite the lack of resilience at
community level, there will have been benets to the close-knit and inward-
focused emotional connections of Neanderthals. An internal or close-knit
emotional focus, and with this greater levels of internal social cohesion,
can foster greater levels of give and take within the living group. Close-knit
Neanderthal groups would have beneted from widespread care, willing-
ness to take risks on behalf of the group, and individual emotional resilience
(discussed in Chapter 2).
There are other practical advantages to close kit emotional dispositions.
Limiting social mobility between groups can also reduce the energetic
costs of such travel, which, as we have seen, can be extensive to maintain
functioning friendships. For Neanderthals, the travel cost of maintaining
social networks are likely to have been even greater than those of modern
412 HIDDEN DEPTHS
humans. Their robust body, for example, may have added at least 10% to the
energetic costs of travel, even before we take into account low population
densities, making distances between living groups much greater (Church-
ill 2014). Moreover, there is no need to manage challenging relationships
outside of a largely kin-based social group. As we have seen in Chapters 4
and 5, avoidance of other groups can be an eective social strategy for
avoiding aggressive encounters. The more pronounced brow ridge of the
archaic population would have restricted subtle muscle movements around
the eyes, limiting the movements that may have been important to how
modern humans created aliative gestures of recognition and sympathy,
fostering trust (Godinho, Spikins, and O’Higgins 2018). Furthermore, individ-
ual emotional resilience, rather than emotional vulnerability to lack of social
contact or to loneliness, fosters survival in conditions in which social support
is lacking. Neanderthals may have beneted from being more emotionally
resilient and from not needing to create costly compensatory attachments
to animals or even things (Chapters 6 and 7) at times of social stress. Overall,
their ecological situation and particular biology seem likely to have discour-
aged intercommunity tolerance in Neanderthals, whilst, in contrast, particu-
lar ecological conditions in regions of Africa may have particularly encour-
aged intercommunity tolerance amongst early modern humans (Spikins
et al. 2021). The price of maintaining social connections, both in practical
terms of the costs of travel and in emotional terms of the individual costs of
emotional vulnerabilities to loneliness or lack of belonging, may not have
been worth paying for Neanderthals. Rather than a social or cognitive infe-
riority, a close-knit focus and individual emotional resilience simply seems
to have made more sense in the context in which Neanderthals survived.
Of course, we should always be cautious when we discuss dierences
between populations. Our human biology, whether Neanderthal or mod-
ern human, is only one of many inuences on how we behave (discussed
in Chapters 1, 4 and 5). Culture, upbringing and individual choice play a
key role in who we are, and dierences identied at a group level do not
imply that any individual must be dierent on those terms. It is also easy to
make simple assumptions about what dierences in emotional disposition,
identied from genetics and anatomy, mean. As we have seen in Chapter 8,
we might imagine that wolves, with elevated androgen levels compared
to ‘tame’ dogs, would suer from higher levels of aggression and violence.
The converse is true, with free-ranging dogs being more at risk from lethal
REFRAMING NEANDERTHALS 413
attacks within their own less socially cohesive group than close-knit wolf
packs. In the even more complex situation of human societies, as we have
seen in Chapter 4, testosterone is more associated with competition to t
into social norms of respect than aggression per se. Thus, whilst genetics
and anatomy, including not only cranial anatomy but also 2D:4D digit ratios
(see Chapter 4 and Chapter 8), suggest that Neanderthals also had higher
androgen levels than modern humans, this does not imply higher levels of
violence. In fact, we only see clear evidence of intergroup conict in modern
humans rather than Neanderthals. Whilst external social tolerance may lead
to generous collaboration between groups, greater levels of engagement
between groups also carry risks of an escalation of conict. Emotional dis-
positions have to be understood in context.
Reframing Neanderthals as emotionally close-knit
and modern humans as emotionally approachable
Diering emotional dispositions explain contrasts
in the structure of communities
The archaeological evidence discussed here, alongside the ecological,
genetic and anatomical evidence discussed in Chapters 4, 5 and 8, suggests
that a key distinction aecting dierences in Neanderthal and modern
human behaviour may be their diering emotional dispositions, and dier-
ing social tolerance. These diering dispositions are best seen as dierent
ways of being social. Rather than seeing Neanderthals as cognitively inferior,
or socially less complex, or resorting to shoehorning them into being the
same, these seem to be societies that were more inward-collaborative and
potentially individually independent, or close-knit. In contrast, the modern
human pathway is one of being outward-focused and socially sensitive in
emotional relationships, or being approachable. Each evolutionary pathway
has both advantages and disadvantages in dierent contexts (Figure 9.6).
As we have seen in Part 2, archaeological evidence suggests a pattern in
which modern humans became more socially sensitive and emotionally
vulnerable, expressed in both material culture and relationships with ani-
mals. Neanderthals may have progressed some way along this path already,
given their reduced brow ridge in contrast to early Homo heidelbergensis.
However, in comparison to modern humans, Neanderthals seem to have a
414 HIDDEN DEPTHS
Figure 9.6: Simplied gure to illustrate contrasts between the close-knit emotional dispositions hypothesised to be charac-
teristic of Neanderthals (left) and, in contrast, the approachable dispositions hypothesised to be characteristic of modern
humans in Europe (right). The dierent line patterns between schematic living groups in the latter (right) denote dierent
types and strengths of social connection (e.g. strong bonds with mutual generosity, casual friendships, family or ritual ties
etc). The dashed outer circle (right) denotes a loosely dened regional community. Penny Spikins, CC BY-NC 4.0.
REFRAMING NEANDERTHALS 415
tendency to form close-knit groups, leading them to be highly internally
collaborative yet more suspicious of unfamiliar individuals. As a result, we
see dierences in the relative constraints or openness of large-scale social
interactions between the dierent species. Subtle but important dierences
in emotional dispositions would make the cultural character of Neanderthal
communities distinctive from that of Upper Palaeolithic communities, with-
out any implications for intelligence or social understanding.
Considering changes in emotional dispositions and the focus of emotional
connections may better explain many of the dierences previously attrib-
uted to intelligence, capacities for language or symbolism, or other ways in
which modern populations have been seen as more complex.
Diering emotional dispositions explain previously
enigmatic elements of the archaeological record
Understanding Neanderthal behaviour as reecting a dierent, less
externally socially tolerant but more internally socially collaborative path-
way of human variation gives us a dierent perspective. This dierent
pathway in which Neanderthals are dierently social explains many charac-
teristics which have been interpreted in terms of Neanderthals being on a
lower rung of some cognitive ladder or less socially complex than the mod-
ern humans who replaced them.
Subtle changes in emotional dispositions, driven by changes in the pathways
driving novelty and reward-seeking (through hormones such as dopamine),
stress reactivity (cortisol), competitiveness (testosterone) and the nature of
social bonds (oxytocin, vasopressin and beta endorphins), seen in genetic
evidence (discussed in Chapter 8) and in line with Neanderthals being more
internally cohesive, would have had subtle but important eects.
A reduced drive to seek out novelty, compared to that which is typical of
modern humans (discussed in Chapter 6), explains the rather constrained
nature of Neanderthal patterns of mobility. Unlike modern humans, it seems
that Neanderthals may have felt no particular attraction to the novelty of
strangers and, as a result, their external social relationships seem to have
been oriented around the minimum practical needs. Interactions with neigh-
bouring groups need not have been aggressive, and sometimes resources
416 HIDDEN DEPTHS
and materials travelled across the areas occupied by dierent living groups,
particularly when such resources were important to survival. However, there
may have seemed no particular pleasure in seeking out new friends. An ele-
vated stress reactivity of internally cohesive Neanderthals, in comparison to
the reduced stress reactivity of approachable modern humans (discussed in
Chapters 4 and 5), is also likely to have made the experience of large groups,
particularly of unfamiliar individuals, particularly stressful. This was a close-
knit social life, without any big parties.
It is not surprising that Neanderthal art seems unimpressive in comparison
to that of the Upper Palaeolithic when taken in the context of their inward-
focusing sociality. Neanderthal art is far from elaborate or time-consuming,
mostly requiring only a few minutes of attention. This contrasts markedly
with displays of technological skills in Upper Palaeolithic contexts, not only
in carefully produced artworks but even in int tools such as elaborately
made Solutrean foliate points (Sinclair 2015). This is, however, only what we
expect within inward-focusing social contexts. There is, simply, little need
to impress anyone. Whilst modern humans moved within vast networks
where they needed to develop a social identity and reputation across large
areas, Neanderthals would already be well known within their local group,
without the need for any ostentatious display or for subtle eye movements
to express aliation to strangers (Godinho, Spikins, and O’Higgins 2018).
Added to which, dierences in dopamine production between archaic and
modern humans may have made ‘art’ in aesthetics, depiction or music far
less enticing to the average Neanderthal brain than it is to the modern
human (see Chapter 4 and 5). Nature itself may have been enough of an aes-
thetic delight for Neanderthals, without needing to go to extreme lengths
to produce something articially beautiful. Furthermore, a relative lack of
personal ornaments or cherished possessions also reects this intimate
focus on social life. Without loved ones ever being far away, there would be
no need to rely on alternative sources of security. This greater inward focus
makes sense of why Neanderthal children and adults show a relative lack of
personal symbolic objects compared to those of the Upper Palaeolithic. As
discussed in Chapter 6, whatever their meaning, such objects are likely to
also have been part of compensatory attachments for modern humans, ll-
ing in when caring relationships come under threat. Whatever the ecologi-
cal hardships, growing up as a Neanderthal child in a small inward-focused
group will have encouraged emotional security. Neanderthals may have
REFRAMING NEANDERTHALS 417
experimented out of curiosity, but most probably did not need ‘art’ in any
of its forms.
The nature of social interactions in Neanderthals will also have aected how
innovations may have begun or been adopted (Hovers and Belfer-Cohen
2006). Interactions with new ideas will have been much less frequent, con-
straining their spread. Certainly, at particular times, some individuals, par-
ticularly adolescents and young adults, must have been lured by novelty
and sought out new connections in other groups. Nonetheless, distant
travel by entire groups across the homelands of other groups may have
been rare. Moreover, evidence suggests that even mating networks were
constrained. Those individuals who move between groups may have been
predominantly female, and external matings constrained by lack of con-
nections (Luis Ríos et al. 2015). By implication, it would have been women
who played a particularly signicant role in Neanderthal social connections,
not only in the maintenance of mating networks but in the spread of ideas
and cultural connections across large areas of landscape. This is in no way
surprising, as it is female primates who pass on mechanisms of producing
and using tools. Chimpanzees largely depend on their mothers to learn how
to make and use termite shing sticks, for example. There is no reason to
assume that males were any less competent than females in tool technol-
ogy, simply that in a patrilocal context they are likely to have played a less
signicant role in the spread of shared knowledge and styles. Mobility con-
strained by gender, the comparative rarity of intergroup movements and a
lack of regular aggregations will all have aected the potential for ideas and
ways of doing things to spread.
In being more robust, and so having a greater energetic footprint per indi-
vidual, Neanderthals already suered from a relative demographic restric-
tion to the size of their living groups and to their capacities to reproduce
compared to modern humans in a similar ecological context. Fewer Nean-
derthals could survive on the same resources as modern humans, and it took
more energetic costs for each child raised to adulthood. An additional, indi-
rect eect may come from changes towards increasing tameness or friendli-
ness on reproduction. An extended period of fertility is one of the notable
side eects of increasing friendliness or tameness in other domesticated
animals, including in the silver fox study (see Chapters 4 and 5). Genetic evi-
dence suggests that the generational interval reduced in modern humans
418 HIDDEN DEPTHS
after 40,000 years ago (e.g. from around 30 to around 25 years between
generations) (Macià et al. 2021). Whilst Neanderthals may have been able to
give more care to each child, this increased child security would have come
at a demographic cost. Modern human populations were able to bounce
back more quickly after population declines (as shown from analysis of radi-
ocarbon dated sites following Heinrich events; Bradtmöller et al. 2012).
The comparative failure of early modern human incursions into Europe can
also be explained by their emotional dependence on social networks. Small
groups of humans, unusually dependent on regional interactions not only
for ecological resilience but also as part of their emotional support network,
would be disadvantaged in comparison to inward-focused and independ-
ent Neanderthal populations. Whilst signicant communities of modern
humans, after 40,000 years ago, may have been more successful than Nean-
derthals at times of shortfalls, early incursions of modern populations into
Europe or the Near East would in any case be at a competitive disadvantage
if isolated.
Whilst the demise of Neanderthals is perhaps most likely to relate to either
chance or subtle dierences in biology, the possibility also exists that one
inuencing factor in Neanderthal demise was not that they were vulnerable
but rather that, at least individually and emotionally, they were not vulner-
able enough. Without emotionally needing to form social networks, or seek
support in compensatory attachments, they will have had no need to go
to great costs to maintain social contacts at a distance and, in lacking large
social networks, may have been far more prone to resource shortfalls. That
our relative survival may have come about through emotional vulnerability
is a very dierent type of human evolutionary narrative.
Conclusions
The very presence of Neanderthals challenges us. We know that they were
dierent from ourselves anatomically, with their increased robusticity,
longer, lower crania and prominent brow ridges. Moreover, they were dif-
ferent physiologically and in their brain structures, even if these dierences
can be subtle and evident only at a population level. Furthermore, as argued
here, they seem to have been emotionally dierent in terms of their lev-
els of internal or external social tolerance, their social sensitivity and their
REFRAMING NEANDERTHALS 419
emotional vulnerability. Such dierences are hardly surprising since the line
that led to Neanderthals diverged from that leading to our own species per-
haps as far back as half a million years ago, albeit with some intermixing.
It has been all too easy to t this dierence within a narrative in which ‘we’
modern humans boast superior intellect and social abilities.
Rather than seeing modern humans as socially or cognitively superior to
our close Neanderthal cousins, it seems more appropriate to appreciate
that there are dierent ways of being social. Dierent evolutionary path-
ways between close-knit and approachable emotional dispositions explains
the distinctions we observe in the archaeological record of Neanderthal
and modern human behaviours in Europe. Whilst the former dispositions
led to strong internal bonds and high levels of individual emotional resil-
ience, the latter led to the formation of large social networks, resilient to
resource shortfalls but at the expense of individual emotional vulnerability
and sensitivities to loneliness or a lack of belonging. Neanderthals were no
less human and, like our own species, needed close emotional connections
to survive and thrive. However, the focus of these connections seems to
have diered.
If Neanderthals represent a humanity without our social loneliness, lack of
belonging, or sensitivity to what others think, and with the unquestioning
support and loyalty of a small social group, it is not surprising that we see
interbreeding between these two lineages. Rather than a sign of Neander-
thals being the same as modern humans, it might rather be a sign of what
was attractive about the dierences.
Key points
• Archaeological evidence for dierences in mobility patterns and com-
munity interactions, alongside other lines of evidence (discussed in
Chapter 8), suggest that Neanderthals and modern human communities
show contrasting inward and outward social focus in their community
relationships, described here as internally cohesive and approachable
emotional dispositions.
• Contrasting behaviours may not indicate any inferiority or superiority
but, rather, diering ways of being social.
420 HIDDEN DEPTHS
• Diering emotional dispositions may also explain previously enigmatic
aspects of the archaeological record, such as the characteristics of Nean-
derthal art.
• We are naturally tempted to impose concepts of progression when we
consider our human evolutionary past. Accepting dierences as neither
better nor worse may be important in moving past these narratives.
REFRAMING NEANDERTHALS 421
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Conclusions
What have we learnt?
The origins of our uniquely human emotional connection are rarely central
to any discussion, as we have seen in the Introduction. This is, perhaps, at
least in part, because our human emotions are all too often seen as a weak-
ness, particularly as they may prompt us to behave in ways that may seem
against our rational self-interest. Certainly, our emotional connections to
others can make us vulnerable in certain ways. Compassion may prompt us
to expend precious eort helping others, our need for belonging makes
us vulnerable to loneliness, and our emotional sensitivities make us prone
to suer in many dierent ways. However, rather than being weaknesses,
we have seen that it is in these vulnerabilities that an unrecognised shared
human strength lies. Only if we feel moved by others’ pain or plight will we
be motivated to respond to our vulnerable young or care for adults needing
our help. Only if we feel moved by strangers, and care about their wellbeing,
will we be motivated to extend our world to form communities, and to con-
nect in new ways to animals and things around us. Only if we are sensitive
to the animals, as well as the people around us, will we be able to make new
emotional connections. Without our uniquely human emotional connec-
tions we would not have thrived as a species.
We have seen, throughout our discussions, that our human ancestors were
more emotionally sensitive than our current interpretations of human ori-
gins allow for. Today, we know that we care deeply about the wellbeing
How to cite this book chapter:
Spikins, P., 2022. Hidden Depths: the origins of human connection. Pp. 433–442. York:
White Rose University Press. DOI: https://doi.org/10.22599/HiddenDepths.k.
License: CC BY-NC 4.0
434 HIDDEN DEPTHS
of people close to us. As we have seen in Chapters 1 and 2 of Part 1, this
remarkable depth of human motivation to help others comes from a very
distant past, set within pressures to become more collaborative early on in
our evolutionary history. We are also acutely aware of how others feel and
think about us. As we have seen in Chapter 3 of Part 1, this sensitivity comes
from the signicance of relationships based on trust and the increasingly
signicant importance of our social moral reputation in others’ eyes. We are
also, above all, profoundly emotionally vulnerable. Not only are we vulnera-
ble to emotional disorders, as we typically conceive of them, but, more than
this, as we have seen in Part 2, we are sensitive to the damaging eects of
loneliness and isolation. We only thrive in contexts of genuine care and con-
nection, and seek out new forms of emotional connection whenever and
wherever these may be lacking. As we have seen in Part 3, our peculiarly
acute emotional sensitivities were in no way predestined but rather one
option of many, a road that we might easily not have taken.
The signicance of emotional vulnerabilities and sensitivities to the strength
of our human connections is, in many ways, not a popular narrative. It would
be far more comforting to see ourselves as individually resilient. However,
the converse is perhaps a more realistic view. Our sensitivities and emo-
tional vulnerabilities are not simply key to who we are as humans but are
also a dening feature of our evolutionary success.
Through the chapters of this volume, we have also seen that changes in
emotional capacities, rather than primarily intelligence or brain size, were
far more signicant to our evolutionary story than has been recognised,
and were likely to have been a driving factor in two major transitions in
human evolution.
Changes in emotional relationships within groups, rather than in rational
thinking abilities, are, here, seen as key to the emergence of the genus
Homo. This key transition occurred after 2 million years ago and involved
movement into a new ecological niche dependent on collaborative
hunting and collaborative infant care, as well as on care for illness and injury.
Increasing brain size in this period is here argued to be an adaptation to
the complexities of new relationships based on trust and emotional
responses to vulnerability within a context of small and highly collabora-
tive social groups, rather than some predetermined element of our hominin
CONCLUSIONS 435
past. Furthermore, the driving factors behind key transformations are
changes in emotional connections, allowing new commitments to both
individuals and to whole groups. Moreover, this key transition is related to
changes in emotional tendencies and capacities that brought early humans
closer to highly collaborative social mammals, rather than elevating them
above nature.
When it comes to the more recent transition around the emergence, and
subsequent expansion, of our own species in Africa, after 300,000 years ago,
it is once again changes in emotional capacities, rather than hard elements
of cognition, that play the most signicant role. New levels of intergroup tol-
erance make new types of connections between dierent groups possible,
buering local shortfalls in resources and providing a mechanism for the
spread of innovations. Reduced stress reactions and heightened social sen-
sitivity open up a window for new externally focused relationships whilst
also bringing new vulnerabilities to loneliness or a lack of belonging. As in
the earlier transition occurring after 2 million years ago, rather than being
extraordinary, these changes in emotional dispositions are also seen in
other highly social species.
Here, we argue that these two transitions were situated within changes in
ecology, and responses common to other species, rather than some human
exceptionalism. Adaptations in emotional disposition towards a broader
response to vulnerability and emotional investments in the whole social
group are argued to play a key role in changes in social relationships that
occur in the emergence of genus Homo, much like similar adaptations in
social carnivores. In turn, changes towards more externally tolerant emo-
tional dispositions are key to the emergence of our own species, much like
transformations seen in species that become more tame. Of course, com-
plex technology, language and culture must have played a role in these
transitions. Nonetheless, without the transformation in social relationships
brought about through changes in emotional dispositions none of these
developments would have been possible.
What makes this interpretation dierent?
This is not an interpretation that necessarily ts neatly within accepted nar-
ratives of human origins.
436 HIDDEN DEPTHS
Firstly, this is no neat progression towards some pinnacle of adaptation.
Changes occurred in a series of stops and starts. Some elements of what we
recognise as our most human emotions appeared early in the evolutionary
record: our response to vulnerabilities in those we love; our willingness to
take risks on behalf of others; our sensitivity to the wellbeing and develop-
ment of infants. Others occurred much later, and we argue here that what
we recognise as our human capacities to extend care and altruism towards
strangers, to develop caring connections across distant relationships,
emerged much later and more recently.
Secondly, the past is here seen as a series of branches and connections
rather than steps along a ladder. Whilst members of the genus Homo trav-
elled their own emotionally collaborative branch, other hominins, such as
the paranthropines, equally viable for over a million years, were less interde-
pendent, and were less dependent on hunted or scavenged meat. Likewise,
in their dierent ecological conditions in Eurasia, other archaic humans such
as Neanderthals were under less selective pressure to focus outwards emo-
tionally and, in turn, were perhaps even more committed to caring within
their close-knit groups. By implication, our evolutionary past may have been
dierent under dierent ecological situations. We might, for all we know, in
a dierent evolutionary past have become less dependent on others around
us for a sense of belonging or emotional support than we are today, be less
interested in what lies outside our own small social group, or be dierent in
all kinds of ways.
Thirdly, in this evolutionary history, changes in emotional capacities brought
us closer to, rather than further away from, other animals. Changes, rstly, in
our response to vulnerability and, secondly, in our friendliness toward stran-
gers, are key to what makes us human. However, they do not make us fur-
ther away from other animals or nature in general. Rather, these are shifts in
focus, and ones that in many ways bring us closer to other animals.
Perhaps most signicantly, an emphasis on our emotional minds as cen-
tral to our evolutionary history is relatively new. No one would argue that
language, technical intelligence or our highly complex culture are not sig-
nicant in our evolutionary history, nor that they are not key elements that
mark us as dierent from other animals. Yet these capacities have been given
CONCLUSIONS 437
priority in our evolutionary story for far too long. Our emotional minds, and
the role they play in our human connections, may be more important to
the better part of our natures and, as such, deserve greater attention in our
evolutionary story.
Some of this may feel challenging.
The emphasis we see here on the biological basis for emotional motiva-
tions and their inuence on behaviour may feel uncomfortable, particularly
amongst those who might argue that emotions are a product of culture
and not biology. Here, again, no one would deny that conscious choice or
accepted cultural norms play an important role in how we behave, or that
rationality is key to how we think, or that emotions are aected deeply by
individual and social circumstance. Our physiology, emotional capacities,
thoughts and cultures interact with each other in complex ways. Empha-
sising the inuence of the biological basis of our minds on who we are is
not to see this as a predetermined genetic blueprint but to recognise that
rational thought is grounded in physical experiences and incorporates feel-
ing, and that the biological basis of our emotions play a role in who we are
as humans.
The concept of distinct, and emotionally dierent, hominid branches as
largely equal options, surviving or declining often through the vagaries of
chance, can also feel disconcerting. Whilst we used to view Neanderthals
as inferior, and now feel more uncomfortable in doing so, it has instead
become fashionable to see them as so similar to ourselves as to be eec-
tively the same. Responding to the challenge of dierence by denying it is,
however, too easy. The dierence we outline here between Neanderthals
and modern humans, related to emotional capacities and tendencies, may
not be related to intelligence or culture. However, to consider this dierence
as about equally weighted options, much like those we see between rela-
tives in canids or non-human primates may, nonetheless, create tension. Yet,
the existence of dierent evolutionary branches and dierent possibilities
for humans in the past seems important. It adds even greater weight to the
argument that we need to be better at understanding not just how other
species can be equal but dierent, rather than simply the same as ourselves,
but how this holds true for other people around us as well.
438 HIDDEN DEPTHS
A more nuanced appreciation of diversity is also key to the portrayal here of
autism, and other elements of cognitive dierence, not as disorders as much
as adaptations to new collaborative moralities in which dierent individuals
full dierent roles. An autistic mind is dierent, but not better or worse,
than a neurotypical one and this itself can be a challenging narrative, par-
ticularly where many see autistic individuals as less social, rather than dif-
ferently social. The principle of dierent but equal can be dicult to accept
where narratives of superiority often feel more comfortable.
When we are used to narratives of human origins that stress our superiority,
it can be hard to view our emotional connections to each other as, in some
ways, similar to those of animals that we share our lives with as inferiors,
such as dogs. Yet it might be important to acknowledge that the same pres-
sures towards interdependence in social carnivores that led to their close
emotional bonds, willingness to defend each other, share risks in nding
resources and share resources themselves, and care for vulnerable infants
and adults, also played an important role in our evolutionary past. Equally,
our profound sensitivities to each other’s feelings, our need for aection and
belonging, were also a response to similar pressures felt during domestica-
tion to forge close emotional bonds through vulnerability.
Whether we have succeeded in genuinely moving away from traditional
ideas of human origins as about a progression towards some superior
being, of course, remains to be seen. However, there can scarcely be a more
important moment to reect on our origins and what they mean for today.
Focusing on the signicance of emotions, and with them on emotional vul-
nerabilities, allows us to question many developments typically portrayed as
key human achievements. A reappraisal of the appearance of art, aggrega-
tions and the domestication of wolves situates humans in these processes as
both remarkable and, at the same time, emotionally vulnerable and deeply
inuenced by biology. These reappraisals can be uncomfortable. The rise of
elaborate art and personal ornamentation in Ice Age Europe is here inter-
preted, at least in part, as emerging through new emotional insecurities, a
concept that may not mesh well with ideas of art as a symbol of elevated
cognition and aesthetics. The rise of large-scale social networks associ-
ated with the emergence of our own species is not here seen as evidence
of a new social ability but rather new needs for connection and belonging
CONCLUSIONS 439
arising from new emotional vulnerabilities. This may be a dicult message,
given how much more pleasing it feels to be seen as a species with unique
and elevated levels of social intelligence rather than one uniquely socially
needy. Likewise, that the ‘domestication’ of wolves is here argued to be a
response to shared emotional needs and sensitivities between wolves and
humans, rather than human innovative air, presents ourselves in a more
emotionally vulnerable light than is typical.
There can hardly be a more important time to recognise, in the face of
climate change, that we are not elevated above other species, nor are we
invulnerable. By highlighting what connects us to the rest of nature, and
the complex paths of dierent but equal evolutionary options, we may be
at least beginning this process. Those motivations that make us sacrice for
the good of others come not from some elevation above a natural world of
competition but rather from a commonality with many highly social ani-
mals. Those motivations that make us reach out despite dierences, or con-
nect across borders, are equally rooted in a biology common to some other
animals. At our best, we are part of nature.
The signicance of our emotional sensitivities and vulnerabilities also makes
more sense of our existence in a modern world. We have seen that our inter-
dependence, and those connections we create through emotional vulner-
abilities, rather than any individual independence, was key to making us
human. Throughout our evolutionary history, humans increasingly needed
each other more intensely, not just practically but also emotionally. This was
key to the formation of close-knit collaborative groups and networks, not
just an unfortunate side eect. By recognising the importance of emotions
to our uniquely strong and wide-ranging connections and uniquely human
means of collaboration, we must at the same time acknowledge the signi-
cance of our sensitivity to others’ pain or distress, as well as that to loneliness
or a lack of social recognition.
There is, of course, a lot more to nd out. We cannot help but wonder about
what dierent emotional biology may have characterised the many dier-
ent hominin species in the past. As we add increasing complexity to our
evolutionary tree, dierent types of social relationships, with perhaps no
parallels today, may emerge. Equally, whilst we would be mistaken to pit cul-
ture against biology in our explanation of behaviours, we are left wondering
440 HIDDEN DEPTHS
about what relationships between these two realms motivated individuals
in the past – to what extent any Neanderthal’s motivations to care for the
vulnerable were driven by how they felt or by how they were expected to
behave, for example. There is also far more to know about interpersonal
variability in emotional responses and capacities. It seems probable that,
as much as today, some individuals in the past were deeply connected
to objects that provided them with a sense of comfort or to animals that
provided emotional support and companionship, whilst others felt little of
these needs or responses. Some were without doubt more caring or more
emotionally vulnerable than others. A perspective on past societies that
integrates emotional variability may yet be to come.
There has been a simplication of many complex issues, and an overview
of detailed evidence in order to achieve an understanding of the broad pat-
tern of our human origins, and many of these arguments would benet from
greater depth. We have neither attempted to disaggregate dierent com-
plex emotions, such as gratitude or shame, nor separated the nature of our
close emotional connections into dierent ways we view love, such as roman-
tic or parental, or close aection between friends. There is also much more
that could be said about the relationship between emotions, bodies and
touch. Furthermore, the details of this new narrative are bound to change
with new ndings, and some arguments presented here maybe overturned
in future. However, I hope that the signicance of our human emotional
motivations towards others, and the better part of our natures, remains.
Why should this new version of our evolutionary past
matter for the future?
Important insights gained from the hidden depths of our evolutionary past
may help us navigate our futures.
The long timescales of our distant past give us new perspectives. Thinking
of our evolutionary past as a testbed of what works to foster our shared
survival against the odds shows that caring about others, and responding
to their vulnerability, has been the most successful long-term strategy of
all. This is most obvious in simple economics. People are most likely to sur-
vive where strong bonds provide the give and take that means that others
CONCLUSIONS 441
are around to help in hard times. Less obviously, however, it is only in envi-
ronments that are socially and emotionally supportive that we develop the
levels of safety and condence that prompt us to be motivated to help oth-
ers. This matters for the future. As much as we need practical solutions to
climate change, or other threats, we need these insights to develop social
and emotional solutions as well.
This is not what we expected to nd. We seem to nd it easy to create sto-
ries about our evolutionary past to make ourselves feel superior or invulner-
able but, on closer attention, these do not hold up to scrutiny. We like to
think of ourselves as exceptional and above other living things. Yet this is far
from the case. Like other animals, we are vulnerable to what happens in the
world around us. Moreover, it clear that the processes that drove how our
emotional connections evolved have much in common with those seen in
other social animals. In many ways, we have travelled on a journey alongside
these animals, not on an exceptional path away from them. We like to reas-
sure ourselves of our intellectual superiority, perhaps imagining that this
intellect will save us from whatever challenges we face. However, in the past,
it has been our emotional bonds and our capacities to care for others that
have fostered survival. We like to think of ourselves as independent. Yet, in
reality, we are profoundly connected, not only in practical terms but also
in how we feel. We may only rarely be entirely carried away by feelings such
as compassion, guilt, sympathy or gratitude, yet they exert a surprisingly
profound inuence as an integrated part of our thinking. Even as infants,
we quickly become aware of how others feel about us, and decide how to
behave on the basis of our sensitivity towards others’ feelings and how they
might react. We are uniquely sensitive to the most subtle of facial expres-
sions, to the barest hint of judgement or rejection, and to the slightest of
social signs that others might approve or disapprove of us, for example. View-
ing or experiencing courage, heroism or acts of supreme altruism elevates
us, profoundly inspiring us to do things for a greater good. Yet, fear of failure,
the concepts of honour or respect, and the prospect of loneliness drive us
to all kinds of often unhealthy or dangerous extremes. We suer in a very
physiological sense if we cannot exercise our natural tendencies to care for
others, and be cared for, and to belong and be appreciated. Indeed, we are
only just beginning to recognise our profound need for genuine emotional
connection, and not supercial social interactions, tweets or inuence.
442 HIDDEN DEPTHS
In the hidden depths of the distant archaeological record we can see that
our emotional sensitivities, so long derided as weakness, are actually our
greatest strengths, albeit strengths that needs nurturing. We are innately
wired to care for living and non-living things, to seek emotional comfort
and to reach out to form connections. When the going gets tough, we
tend to help each other. But we were never meant to be individually resil-
ient, and we struggle to nd the courage to help others, to explore new
ideas and to be creative without the genuine emotional connections we
need. We cannot hope to become grounded, courageous and committed
to shared goals unless we create the structures that foster supportive rela-
tionships and provide us with safe havens of comfort in nature, animals and
even cherished things.
Today, we face some of the most serious challenges we have ever experi-
enced. As well as the direct eects of climate change, bringing pressures
on land and resources, and the impacts of new diseases, we also face
entrenched hatreds, rising inequality and the emotional pressures brought
about by experiencing ecological disintegration. However, it has been old
narratives about who we are that played a role in creating many of the prob-
lems which we face. It is not dicult to see that cultures that elevate selsh-
ness, inequality and exploitation of natural resources have been supported
by ideas of innate human competitiveness, invulnerability and superiority
over nature. If we can look beyond these assumptions and recognise a pre-
viously hidden past of connection, caring and sensitivity, we could harness
the signicance of these connections and vulnerabilities in creating resilient
communities. We might begin to reframe who we are and, in turn, change
the world that we create around us.
Index
Page numbers in italic indicate gures and in bold indicate tables.
A
Aché hunter-gatherers 108, 109,
140, 407
aective empathy 44, 49, 55, 133
archaic and early modern
humans 99
australopithecines 82
early Homo 86, 88, 90
African wild dogs 49, 348, 394
aggression, androgens and 184
Agta hunter-gatherers 408
Aka hunter-gatherers 304, 314
alliance networks
see social networks.
alloparenting
see collaborative parenting.
Alouatta
see howler monkeys.
Altai Mountains, Siberia 399
Altamira, Spain 403
altruism
see empathy, compassion and
generosity.
Altxerri, Spain 318
Amud cave, Israel 399
anaemia 84
Anbarra hunter-gatherers 299,
304, 309
androgens 51, 53, 182, 183, 184,
353, 367, 413
animals
as imaginary friends 267
cherished objects in form of
257, 258, 268, 269, 271,
274, 278, 279
early evidence of relationships
with 105, 323
in art and artefacts 276, 278,
279, 317
see also dogs; social mammals.
animistic traditions 307, 315
444 HIDDEN DEPTHS
apes
consolation 27
gibbons 79, 80, 185
gorillas 185
helping behaviours 37, 42
insights into evolution of human
empathy 36, 38, 45
responses to death 30, 31
sexual dimorphism 185, 186
theory of mind 41
see also bonobos; chimpanzees.
archaeological evidence 5
craniofacial changes 231
early modern human community
relationships 400, 405
group size in early humans 176
inbreeding 176, 400
intergroup interactions 176,
178, 231, 233
Neanderthal community
relationships 396, 405
proliferation of non-functional
objects 260, 274, 277,
278, 279
raw material movements 176,
178, 231, 397, 403
sensitivity to reputation 146, 147
wolf domestication 312, 316, 357
see also art and artefacts; care for
vulnerable adults.
Ardipithecus 77
arm injuries 80, 96
art and artefacts 132
aesthetics of 146, 147
autistic artists 153
cave and rock art 131, 132, 318,
400, 402
dogs and wolves in 317
earliest evidence for stone tool
use 84
early evidence of relationships
with animals 105, 323
infant-like proportions 106
Neanderthals 105, 106, 262, 400,
401, 402, 416
portable art and ornamentation
260, 274, 277, 278, 279, 318,
400, 401, 403
proliferation of symbolic
objects 260, 274, 277,
278, 279
raw material movements 176,
178, 231, 397, 403
therianthropic artefacts 276,
277, 280
assisted childbirth 97, 106
attachment insecurity 236, 238
attachment objects
see cherished personal
possessions.
Aubesier 11 fossil 96
Australian indigenous peoples
dingoes and 298, 299, 304,
308, 324
food sharing 103
lack of dogs art 318
reputation 140
social gatherings 410
australopithecines 77, 78, 82, 106,
186, 196
see also paranthropines.
Australopithecus africanus
77, 81
Australopithecus sediba 78, 81
autism spectrum condition
150, 153
avoidance behaviour, changes
in 183, 184, 193
Awá hunter-gatherers 274
Awajishima Monkey Centre,
Japan 79
B
baboons 85, 179, 191, 192, 194
Baka hunter-gatherers 98, 196
bats 34, 35
INDEX 445
Bayaka hunter-gatherers 240, 408
beads 262, 275, 279, 403
Berekhat Ram gurine 106, 261
beta endorphins 53, 182, 183,
224, 310
bifaces
aesthetics of 146, 147
elephant bone 105, 323
birds
importance to Neanderthals
105, 323
social intelligence 144
birth assistance 97, 106
Blombos Cave, South Africa 261
bone tools 105, 323
Bonn-Oberkassel, Germany 314
bonobos
androgen responses 189
birth assistance 97
comparison with chimpanzees
350, 352, 353, 356, 366,
394, 395
consolation 27
eye gaze 367
helping behaviours 37, 42
inhibitory control 149
insights into evolution of human
empathy 36, 45
play 149
self-domestication 226, 366
tolerance 20, 173, 180, 189, 203,
350, 352, 353, 356, 366
tools 354
tooth loss 85
Border Cave, South Africa 262
Boxgrove, England 357
brain size, early Homo 89, 90,
347, 373
burial practices 105
cat burials 317
dog burials 105, 313, 316
early Homo 91
early modern humans 98
fox burials 317
grave goods 262
Neanderthals 75, 94, 98, 105
C
Callitrichidae
see marmosets; tamarins.
Cap Grand, France 399
care for vulnerable adults 71
archaic and early modern
humans 91, 94, 99
australopithecines 77, 82
early Homo 82, 88, 90
implications for other human
traits 106, 107
interpretation challenges 79, 99,
101, 103
other realms of evidence
and 104
cat burials 317
cave and rock art 131, 132, 318,
400, 402
Cercopithecidae
see monkeys.
cerebellum 391, 392
Châtelperronian industries 262
Chauvet cave, France 131
cherished personal
possessions 192
children’s personied
objects 241, 257, 258, 268,
271, 274
common forms or features 271
cultural variations 272
in adulthood 241, 268,
270, 271
symbolic objects in archaeological
record 260, 274, 277,
278, 279
childcare 22, 23, 51
care of dead infants 30, 32
Neanderthals 96, 418
see also collaborative parenting.
446 HIDDEN DEPTHS
children and infants
attachment insecurity 237
empathy, compassion and
generosity 22, 25, 27, 40, 42
imaginary friends 241, 265, 266
personied objects 241, 257,
258, 268, 271, 274
sensitivity to emotional
motivations 135
theory of mind 41
chimpanzees
adopting infants 35, 241
androgen responses 186, 188, 190
autistic traits 152
care of dead infants 30, 31
comparison with bonobos 350,
352, 353, 356, 366, 394, 395
Down's syndrome infant 92
food sharing 23, 51
grooming 37, 38
helping behaviours 37, 42
inhibitory control 149
injuries 80
insights into evolution of human
empathy 36, 38, 45
mutualistic altruism 34
novelty seeking 196
pant hoots 180
play 149
reciprocal altruism 34
responses to death 30, 31, 105
sensitivity to emotional
motivations 136
sexual dimorphism 186
social intelligence 144, 145
social networks 175, 370
targeted helping 29
teaching behaviours 146
territorial aggression 174,
186, 188
theory of mind 41
tolerance 20, 174, 186, 188, 190,
196, 350, 352, 353, 356, 366
see also bonobos.
tools 354, 417
Cis-Baikal, Siberia 315, 316
cognitive empathy 28, 43, 44,
55, 133
archaic and early modern
humans 99
early Homo 86, 88, 90
collaborative defence 33, 46
collaborative hunting
early Homo 84
early modern humans 403
mammoth hunting 403
modern hunter-gatherers
109, 406
social mammals 33, 34, 42, 48,
354, 394
whale hunting 406
collaborative parenting
early Homo 84, 89, 90
social mammals 19, 33, 46,
49, 358
teaching behaviours and 146
compassion
see empathy, compassion
and generosity.
compensatory attachments
192, 241
cherished objects in adulthood
241, 268, 270, 271
children’s imaginary friends 241,
265, 266
children’s personied
objects 241, 257, 258, 268,
271, 274
symbolic objects in archaeological
record 260, 274, 277,
278, 279
competition, androgens and 184
consolation 26, 42
convergent evolution
between bonobos and
humans 366
between dogs and humans 319,
320, 321, 322, 367
INDEX 447
cortisol 182, 183, 190, 224, 360, 367
Corvus
see ravens.
Cova Foradà, Spain 97
COVID-19 pandemic 259, 273,
310, 374
coyotes 34
craniofacial anatomy
changes in 134, 175, 226,
227, 231
dogs 226, 227
Neanderthals 227, 390, 391, 392
craniosynostosis 92
Cree people 410
cultural transmission of
knowledge 144
cynodonts 21
D
‘dandelions ‘;dandelions 201
death, responses to 30
care of dead infants 30, 32
early Homo 91
Neanderthals 75
social mammals 31, 32, 105
decolonisation 390
Dederiyeh, Syria 98, 105
degenerative diseases
see care for vulnerable adults.
Denisovans 91, 393
depression 158, 199, 230, 236
Desmodontinae
see vampire bats.
digit ratios 186
Dinaledi Chamber, South Africa
see Rising Star Cave system,
South Africa.
dingoes 30, 105, 298, 299, 304,
308, 324, 361, 362
Dmanisi, Georgia 85
dogs
approach behaviours 197, 200,
228, 367
as form of technology 302, 303,
304, 309, 313
attachment insecurity 236
attachments to objects 263
breastfeeding of puppies
306, 309
burials of 105, 313, 316
care for ill dogs 314
comparison with wolves 356,
359, 360, 361, 365, 394, 395
consumption of 305
craniofacial anatomy 226, 227
dingoes 30, 105, 298, 299, 304,
308, 324, 361, 362
disdain and abuse of 304
emotional role of 306, 310
emotional vulnerabilities 323, 362
evolutionary convergence in dogs
and humans 319, 320, 321,
322, 367
eye gaze-based bonding 197, 360
generalised reciprocal
altruism 35
hormones 51, 197, 200, 360, 367
in art and artefacts 317
in modern industrialised
contexts 310
interbreeding with wolves
312, 326
mating system 358
modern hunter-gatherers
and 298, 299, 300, 301, 302,
303, 307, 314, 324
sensitivity to emotional
motivations 136
social sensitivity 323, 362,
368, 395
stress reactivity 191, 192, 193,
360, 367
tolerance 191, 192, 193, 197, 200,
228, 356, 359, 360, 361, 365
see also wolf domestication.
Dolní Vĕstonice, Czech Republic 98
dolphins 28, 29, 31
448 HIDDEN DEPTHS
domestication 223
anatomical changes 225,
226, 227
cortisol and 191
human self-domestication 225,
227, 366
silver foxes 223, 228
see also wolf domestication.
dopamine 23, 46, 53, 182, 183,
193, 224, 416
dopamine receptor genes 197
Down's syndrome 92
E
eagle talon artefacts 105, 401
early Homo
aective empathy 86, 88, 90
brain size 89, 90, 347, 373
burial practices 91
care for vulnerable adults 82,
88, 90
cognitive empathy 86, 88, 90
collaborative hunting 84
collaborative parenting 84, 89, 90
dierent evolutionary
pathways 347
digit ratios 186
group size 176
meat eating 83, 84, 89, 90, 147,
177, 194
relationships with animals 105
reputation 136, 137, 138
responses to death 91
sexual dimorphism 186
social networks 175
ecological pressures 53, 56, 82, 89,
203, 233, 346
economics students 237
Efe hunter-gatherers 108
Ein Mallaha, Israel 317
Ein Qashish, Israel 399
El Sidrón, Spain 95, 97, 196, 397,
399, 400
elephants 27, 28, 29, 30, 31, 105,
175, 323
emotional commitments
see trust and emotional
commitments.
emotional contagion 26
emotional dispositions
chimpanzees and bonobos
compared 394, 395
wolves and African wild dogs
compared 394
wolves and dogs compared
394, 395
emotional vulnerabilities 110,
141, 234, 235, 238, 370, 374
dogs 323, 362
see also compensatory
attachments.
empathy, compassion and
generosity 19
aective empathy 44, 49, 55
animal comparisons 27, 36, 42,
44, 49
children and infants 22, 25, 27,
29, 40, 42
cognitive empathy 28, 43, 44, 55
consolation 26, 42
emotional contagion 26
helping behaviours 24, 28, 32,
35, 37, 42
neurobiology of 21
responses to death 30, 32
selection pressures 31, 35, 50, 54
stages in evolution of 25,
36, 42
see also care for vulnerable adults.
evolutionary pathways in
tolerance 343
chimpanzees and bonobos
compared 350, 352, 353,
356, 366
convergence in bonobos and
humans 366
INDEX 449
convergence in dogs and
humans 319, 320, 321,
322, 367
dierent pathways in human
evolution 347, 366, 369
implications of new
perspective 372
wolves and African wild dogs
compared 348
wolves and dogs compared 356,
359, 360, 361, 365
eye gaze 197, 360, 367
F
face shape changes 134, 226,
227, 231
facial expressions 134, 236, 367
fear, reductions in 190
Font de Gaume, France 318
food sharing
modern hunter-gatherers
103, 109
social mammals 23, 33, 51
foxes 191, 225
burials of 317
silver 223, 228
G
generalised reciprocal altruism 35
generational intervals 418
generosity 188
see also empathy, compassion and
generosity.
genetic evidence
autistic traits in primates 152
generational intervals 418
group size in early humans 176
hormones and tolerance 182
inbreeding 176
interbreeding of human
species 233
intergroup movement 196,
400, 403
wolf domestication 312, 326
giant gelada baboons 84
gibbons 79, 80, 185
glucocorticoids 182, 183, 190, 224,
360, 367
goal seeking exploration 193
Gombe National Park,
Tanzania 187
Gorham’s Cave, Gibraltar 402
Gorilla
see gorillas.
gorillas 185
gratitude 40, 230
grave goods 262
group selection 35
group size, early Homo 176
Guattari 1 fossil 96
guilt 142
H
Hadzabe hunter-gatherers 302
Hadza hunter-gatherers 103, 407
handaxes
aesthetics of 146, 147
elephant bone 105, 323
head injuries 96
healthcare provisioning
see care for vulnerable adults.
helping behaviours 24, 28, 32, 35,
37, 42
see also care for vulnerable adults.
Herto, Ethiopia 231
hibernation 348, 391
Hohle-Fels, Germany 276
Hohlenstein-Stadel, Germany
276, 277
Hominoidea
see apes.
Homo erectus 85, 86, 87, 102, 231
Homo ergaster 85, 88, 102
Homo oresiensis 91, 393
Homo heidelbergensis 413
Homo longi 91
450 HIDDEN DEPTHS
Homo luzonensis 393
Homo naledi 90, 91, 186, 231, 347,
373, 393
Homo sapiens neanderthalensis
see Neanderthals.
Homo, early
see early Homo.
hormones 7
androgens 51, 53, 182, 183, 184,
353, 367, 413
beta endorphins 53, 182, 183,
224, 310
changes in approach behaviour
and 183, 193, 367
changes in avoidance behaviour
and 183, 184, 193
cortisol 182, 183, 190, 224, 360,
367
dogs 51, 197, 200, 360, 367
dopamine 23, 46, 53, 182, 183,
193, 224, 416
empathy and 22, 23, 46, 50
glucocorticoids 182, 183, 190,
224, 360, 367
oxytocin 22, 23, 46, 51, 146, 182,
183, 198, 224, 236, 310, 353,
360, 367
serotonin 198, 200, 224, 236
teaching behaviours and 51, 146
testosterone 51, 53, 182, 183,
184, 353, 367
tolerance and 181, 183, 354
vasopressin 23, 52, 182, 183, 224
howler monkeys 191
HPA (hypothalamic-pituitary-
adrenal) axis 53, 224, 321,
360, 367
human-animal artefacts 276,
277, 280
hunter-gatherers, modern
care for vulnerable adults 88,
98, 109
cherished possessions 273
collaborative hunting 109, 406
coping with emotional
vulnerabilities 239
dogs and 298, 300, 301, 302, 303,
307, 314, 324
food sharing 103, 109
food sources 89
inhibitory control 150
injuries 80
intergroup violence 188, 189
motivations for helping 103
novelty seeking 196
reputation 139
social networks 174, 370,
406, 408
whale hunting 406
xaro network 406, 408, 409
hunting
see collaborative hunting.
hyenas 28, 47, 89
Hylobatidae
see gibbons.
hyperostosis 84
hypervitaminosis 86, 102
I
Ileret, Kenya 176
illness
see care for vulnerable adults.
imaginary friends 241, 265, 266
inbreeding 176, 196, 400
individual rational
self-interest 237
infectious diseases 73, 88
inhibitory control 148
injuries
arm 80, 96
head 96
leg 80, 95
see also care for vulnerable adults.
interbreeding
dogs and wolves 312, 326
human species 91, 196, 233
INDEX 451
intergroup movements 196
australopithecines 196
early modern humans 403
Neanderthals 196, 400, 417
see also raw material movements.
intergroup relationships
see social networks; tolerance.
Inuit 104, 150, 152, 301, 302,
307, 406
J
Jebel Faya, Saudi Arabia 233
Jebel Irhoud, Morocco 231
Jo'huansi hunter-gatherers 140,
262, 406, 408, 409
K
Kalahari 232
Kibale National Park, Uganda 85,
145, 187
kin-based altruism 33, 35
KNM-ER 15000 fossil
see Nariokotome Boy fossil.
KNM-ER 1808 fossil 85, 88, 102
Koobi Fora, Kenya 85, 88
Koster site, Illinois 315
Krapina 37 fossil 96
Krapina 180 fossil 96
Krapina, Croatia 401
L
l’Hortus, France 95
La Chapelle-aux-Saints 1 fossil
93, 94
La Ferrassie 1 fossil 95
La Ferrassie 2 fossil 95
La Lazaret, France 357
La Quina 5 fossil 96
Le Closeau, France 313
leg injuries 80, 95
Lemuroidea
see lemurs.
lemurs 184, 347
Lezetxiki, Spain 398
life expectancy 106
limb injuries 80, 95, 96
lion-headed gure 276,
277, 280
lions 28
Loma de los Muertos,
Patagonia 317
London Blitz 273
loneliness 110, 236, 241, 269
long-term goals, helping
towards 41, 42
LuiKotale, Democratic Republic of
Congo 173, 189
Lutrinae
see otters.
Lycaon pictus
see African wild dogs.
M
Macaca spp
see macaques.
macaques 79, 80, 180
Makapansgat pebble 106
Malapa, South Africa 78
mammals
as imaginary friends 267
cherished objects in form of
257, 258, 268, 269, 271,
274, 279
early evidence of relationships
with 105, 323
in art and artefacts 276, 278,
279, 317
see also dogs; social mammals.
mammoth hunting 403
marmosets 19, 27, 35, 46, 51, 148
Martu hunter-gatherers 140,
304, 410
mate selection 36
material evidence
see archaeological evidence.
452 HIDDEN DEPTHS
Matinen hunter-gatherers 306
meat eating, early Homo 83, 84,
89, 90, 147, 177, 194
medicinal knowledge,
Neanderthals 97
meerkats 23, 46, 51, 146
MH1 fossil 78, 81
Misliya cave, Israel 233
mongoose 28
monkeys
autistic traits 152
empathy 26, 27, 35, 42, 46
inhibitory control 148
injuries 79, 80
novelty seeking 194
pair bonding 19, 27, 46, 51
stress reactivity 191, 192
teaching behaviours 146
tolerance 179, 180, 191
tooth loss 85
monogamy 184
Montespan, France 313
morally discriminate helping 42
mortuary practices 30, 105
cat burials 317
dog burials 105, 313, 316
early Homo 91
early modern humans 98
fox burials 317
grave goods 262
Neanderthals 75, 94, 98, 105
mutualistic altruism 34, 35
N
Nariokotome Boy fossil 85, 87
Neanderthal 1 fossil 96, 390
Neanderthals 73, 91, 93, 387, 389
art and artefacts 105, 106, 262,
400, 401, 402, 416
as emotionally close-knit
413, 414
burial practices 75, 94, 98, 105
care for vulnerable adults 74,
92, 94
childcare 96, 418
community relationships 396,
405, 411, 414
craniofacial anatomy 227, 390,
391, 392
digit ratios 186
hibernation 348, 391
importance of animals to
105, 323
interbreeding with modern
humans 233
intergroup movements 196,
400, 417
medicinal knowledge 97
raw material movements 397
relationships with
animals 105
reproduction 418
stress reactivity 416
symbolism 262, 263, 400
‘Ned ‘fossil; Ned fossil 74
neocortex size 144, 175
neurobiology
of empathy 21
of tolerance 181, 183
see also hormones.
neurodiversity 150, 153
neuroendocrine responses
see hormones.
norepinephrine 224
novelty seeking 193, 416
O
Ohalo 2 fossil 98
Olduvai, Tanzania 84, 147, 176
Olorgesailie, Kenya 84, 232
Omo 1 fossil 231
Onges hunter-gatherers 308
‘orchids ‘ 201
otters 28
oxytocin 22, 23, 46, 51, 146, 182,
183, 198, 224, 236, 310, 353,
360, 367
oxytocin receptor genes 200
INDEX 453
P
Pad'-Kalashnikova, Siberia 315, 316
painted wolves, African
see African wild dogs.
pair bonding 19, 27, 46, 51, 53,
185, 358
Pan paniscus
see bonobos.
Pan troglodytes
see chimpanzees.
Papio
see baboons.
paranthropines 84, 346
parietal cortex 391, 392
Pavonini
see peacocks.
peacocks 32
personal ornamentation
see portable art and
ornamentation.
personal possessions
see cherished personal possessions.
perspective-taking 26, 28
see also theory of mind.
pets 135
as compensatory
attachments 241
see also dogs.
Pintupi hunter-gatherers 103
plants, medicinal 97
Platyrrhini
see monkeys.
Pont d'Ambon, France 313
portable art and ornamentation
260, 274, 277, 278, 279, 318,
400, 401, 403
prairie voles 51, 184
Předmostí, Czech Republic 314, 403
primates, non-human
see apes; bonobos; chimpanzees;
monkeys.
pygmy chimpanzees
see bonobos.
Q
Quafzeh 11 fossil 261
R
rats 28, 29, 34, 35, 224
Rattus
see rats.
ravens 144
raw material movements 176,
178, 231, 397, 403
Razboinichya cave, Siberia 313
reciprocal altruism 34, 35
Repair Shop, The 259, 268
reputation 98, 103
aesthetics of artefact form
and 146, 147
costs of concern with 141
early human interdependence
and 136, 137, 138
kindness versus cunning 141, 142
Rising Star Cave system, South
Africa 90
risk-taking 193
robust australopithecines 84, 346
Roche-Cotard mask 106
Rogers teddy bear 257, 258
Romito child fossil 98
S
Salé, Morocco 96
self-control 148
self-domestication, human 225,
227, 366
Selk'nam hunter-gatherers 301
sensitivity to emotional motivations
see trust and emotional
commitments.
serotonin 198, 200, 224, 236
serotonin receptor genes 269
sexual dimorphism 77, 185
sexual selection 36
shame 142, 230
454 HIDDEN DEPTHS
Shanidar 1 fossil 73, 74, 94
Shanidar 3 fossil 95, 96
shell artefacts 261, 262, 403
Shillourokambus, Cyprus 317
Shiwiar hunter-gatherers 88, 109
Shuwaymis, Saudi Arabia 318
silver foxes 223, 228
Sima de los Huesos, Spain 92
Skateholm, Sweden 315
Skhul V fossil 261
social brain theory 141, 142
social carnivores
African wild dogs 49, 348, 394
collaboration 89
consolation 27, 28
inhibitory control 149
insights into evolution of human
empathy 46, 48
kin-based altruism 33
play 149
selection pressures 54
targeted helping 28
see also wolves.
social intelligence 37
versus kindness 141, 142
social isolation 241
social mammals
adopting infants 35, 241
aective empathy 44, 49
cognitive empathy 43, 44
consolation 28
emotional contagion 26
empathy 21
food sharing 23, 33, 51
generalised reciprocal
altruism 35
helping behaviours 37, 42
hormones 23, 46, 51
inhibitory control 149
insights into evolution of human
empathy 27, 36, 42, 44, 49
kin-based altruism 33
mutualistic altruism 34
novelty seeking 194
pair bonding 19, 27, 46, 51, 53,
185, 358
play 149
reciprocal altruism 34
responses to death 31, 32, 105
selection pressures 54
sensitivity to emotional
motivations 136
sexual dimorphism 185
social intelligence 144, 145
social networks 175, 370
stress reactivity 190, 192
targeted helping 28
teaching behaviours 46,
51, 146
see also bonobos; chimpanzees;
dogs; monkeys; wolves.
social mentality theory 236, 238
social networks
early Homo 175
early modern humans 400,
405, 414
modern hunter-gatherers 174,
370, 406, 408
Neanderthals 396, 405, 411, 414
social reputation
see reputation.
social safeness 269, 270
social sensitivity 198, 200, 234,
235, 238, 368, 370, 374
dogs 323, 362, 368
spiritual beings 241, 268
Spy, Belgium 95
St Cesaire 1 fossil 96
Sterkfontein, South Africa 77
Stillwell II site, Illinois 315
stone tools
aesthetics of 146, 147
earliest evidence for use of 84
raw material movements 176,
178, 231, 397, 403
stress reactivity 190, 193, 360,
367, 416
Stw 363 fossil 77, 81
INDEX 455
Sunghir, Russia 98, 102, 403
Swartkrans, South Africa 87, 102
symbolic objects 260, 274, 277,
278, 279
T
Tabun 1 fossil 95
Taï forest, West Africa 188, 195
tamarins 46, 146, 148
targeted helping 26, 28, 42
teaching behaviours 46, 51, 144
teddy bears 257, 258, 268, 269,
271, 272, 278, 279
testosterone 51, 53, 182, 183, 184,
353, 367
theory of mind 41, 133, 142, 146,
151, 357
see also cognitive empathy;
perspective-taking.
therianthropic artefacts 276,
277, 280
tolerance 171, 221
advantages of 230
changes in approach
behaviour 183, 193, 367
changes in avoidance
behaviour 183, 184, 193
constraints and disadvantages
of 234, 235
human self-domestication 225,
227, 366
in human evolutionary past 174
physiological and emotional
reactions to strangers
178, 183
selection pressures 203,
228, 233
see also evolutionary pathways in
tolerance; social networks.
tools
bone 105, 323
chimpanzees and bonobos
354, 417
see also stone tools.
toothlessness 85, 96
toothpicks 97
torticollis 96
Trinil, Java 261
trust and emotional
commitments 129
aesthetics of artefact form
and 146, 147
costs of 141
cultural transmission of
knowledge and 144
drive to understand emotional
motivations 133
early human interdependence
and 136, 137, 138
integration of dierent minds
and 150
kindness versus cunning 141,
142
Tsimane hunter-gatherers 109, 189
Turkana Boy
see Nariokotome Boy fossil.
U
unsolicited helping 41, 42, 43,
86, 88
Ust'-Belaia, Siberia 316
Ust'-Khaita, Siberia 315
'Uyun al-Hammam, Israel 317
V
vampire bats 34, 35
vasopressin 23, 52, 182, 183, 224
Vogelherd, Germany 276, 278, 279
vulnerable adults
see care for vulnerable adults.
W
whale hunting 406
wolf domestication 311
archaeological evidence 312,
316, 357
456 HIDDEN DEPTHS
evolutionary convergence in dogs
and humans 319, 320, 321,
322, 367
genetic evidence 312, 326
nature of 324, 325
wolves
comparison with African wild
dogs 348, 394
comparison with dogs 356, 359,
360, 361, 365, 394, 395
consolation 27, 28
craniofacial anatomy 227
in art and artefacts 317
inhibitory control 149
insights into evolution of human
empathy 48
interbreeding with dogs 312, 326
kin-based altruism 33
mating system 358
pack structure 360
play 149
targeted helping 28
theory of mind 357
tolerance 179, 348, 356, 359,
360, 361, 365
yawn contagion 47, 357
see also wolf domestication.
Wonderwerk cave, South Africa 95
X
xaro network 406, 408, 409
Y
Yamana hunter-gatherers
274, 408
yawn contagion 47, 357
Z
Zhoukoudian, China 357
