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Children’s Development in Light of Evolution and Culture

Children’s Development in Light of Evolution and Culture
by Darcia Narvaez, Peter Gray, James McKenna, Agustin Fuentes and Kristin Valentino
In Narvaez, D., Gray, P., McKenna, J., Fuentes, A., & Valentino, K. (2014). Children’s development in light of
evolution and culture. In D. Narvaez, K. Valentino, A., Fuentes, J., McKenna, & P. Gray, (Eds.), Ancestral
Landscapes in Human Evolution: Culture, Childrearing and Social Wellbeing (pp. 3-17). New York: Oxford
University Press.
With lenses from multiple disciplines, contributors to this volume examine culture and parenting
effects on child development and individual and cultural wellbeing. The contributions examine
in more detail what might be considered baselines for social mammalian and human
development. The volume includes examinations of specific cultures, reviews of hunter-gatherer
cultures on particular topics, evolutionary views of offspring in evolution, as well as mammalian
and human developmental needs. The emphasis is on caregiving and offspring, their interaction,
and how family and community cultures influence and are affected by children.
Keywords: culture, childrearing, evolution
Children’s Development in Light of Evolution and Culture
“All child rearing is based on beliefs about what makes life manageable, safe, and fertile for the
spirit” so that “even with the best, most rational, kindest advice from outside, child rearing will
likely always be so” (Bruner, 2000, p. xii).
Individual humans cannot grow up alone. Like all social mammals, humans need intensive
caregiving in early life to survive, thrive and disperse (Konner, 2010; Williams, 1966). As
childcare takes a great deal of energy, mother-child dyads are necessarily aided by families and
communities (Hrdy, 2009). Indeed, the contexts for raising children among all human societies
include multiple layers of influence and support (Bronfenbrenner, 1979). Culturesocially-
transmitted shared beliefs, understandings, and practicesis one of those influences.
Around the world, families and children are embedded in cultures and sub-cultures that
support and encourage different approaches to childrearing. Some cultures encourage while
others discourage physical closeness, based on potential psychological or physical outcomes;
some consider babies to be in need of wooing into interdependence while others consider them to
be in need of strict discipline to learn independence (Deloache & Gottlieb, 2000; Doi, 1981;
Georgas, Berry, van de Vijver, Kağitḉibași & Poortinga, 2006; Levine & Norman, 2001). Even
within a particular society, the culture of child caregiving can change over time in terms of
family constellation, community traditions and everyday family pragmatics. Such variations in
practices may challenge universalistic models such as that of attachment theory which affixes
attachment labels to particular child behaviors which are matched to particular types of parental
behavior (Bowlby, 1969, 1988; Main, 1995). But if some societies encourage psychological
distance, demonstrating high levels of social detachment (avoidant attachment), can one can
argue, as some do, that avoidant attachment is adaptivewhich is contrary to the claims of
attachment theory (Levine & Norman, 2001)?
The book delves into several issues. First, it probes the question of whether or not there is
an optimal range of infant/childhood care and what that might look like. The beneficial or
“expectable” range of care might to some degree be inferred from the common dimensions of
care in other social mammals, especially primates. We can also discern an expectable range of
care from human beings living in ways consistent with our evolutionary past, to the degree that
we can infer this from diverse lines of evidence. Such evidence includes paleo-ecological
reconstructions and contemporary ethnographic studies elucidating a range of adaptations
beginning with, nomadic foragers (also known as small-band hunter-gatherers; we use the term
hunter-gatherer to represent this type of society). Mobile communities like these represent a
characteristic social structure for much of human history up until to about 10-15,000 years ago
when more sedentary, settled societies emerged (though hunter-gatherers have coexisted since
then as well; Lee & Daly, 2005).
A second question is whether some societies have stepped out of the optimal range for
childrearing (Edgerton, 1991). It can be said, for example, that children who are maltreated (i.e.,
neglected, abused, traumatized) exist outside the optimal range as inferred from their adult
dysfunctions and/or mental disorders and addictions, all of which are clinically evident (Lanius,
Vermetten & Pain, 2010). But how about those whose care does not reach the legal or clinically-
relevant levels of neglect or abuse? Are there other less obvious forms of infant or child
caregiving that damage them in more subtle but still significant ways? Although in the past, and
to a certain extent even in the present, wide ranges in early life caregiving were considered fairly
harmless, increasing evidence shows that traumatic early life experience can be toxic, with
lasting effects on physiological and psychological wellbeing (Shonkoff et al., 2000; 2012).
Many investigators concur on the importance of having an empirically-based, diverse but
solid knowledge base regarding "healthy" development, in humans and other animals, in order to
understand psychopathology (e.g., Cicchetti & Roisman, 2011; Panksepp, 2001). One could
always ask how will we know what is abnormal unless we have a good sense of what the range
of normal is? While recognizing the obvious pitfalls and difficulties of proposing an "optimal
range" for our species, given our great biological and cultural plasticity, this book intends to raise
important new questions that challenge certain assumptions about the appropriateness of infant
and child care practices, especially in the industrialized West. At the very least we need to start a
conversation that moves toward understanding how to identify social caregiving innovations that
push infants and children beyond their adaptive limits. Specifically, we hope to shed light on
what the evolved, expectable contexts for mammalian and human development really are. What
are optimal and suboptimal contexts for human development? What are the effects on children’s
development and adult wellbeing of the wildly divergent physical and social habitats in which
children grow up today, which require behavioral adjustments that were never tested in an
evolutionary context?
We do not idolize ancestral forms of care, nor naively singing their collective praises
without realizing that the usefulness of evolved behaviors can change through time. Nor do we
dismiss the possibility that traits that may have been adaptive at earlier points in our prehistory
are not necessarily compatible with present circumstances (but measuring what is adaptive or not
The sister volume, Evolution, early experience and human development, addresses this question more directly.
is impossible to predict). Indeed, we are mindful of Stephen Jay Gould's insightful perspective
that evolution is all about functional change with structural continuity. We certainly should not
ignore Sarah Hrdy's whimsical but perceptive comments that "A mother today, whether in New
York, Tokyo or Dacca is not just a gatherer caught in a shopping mall without her digging stick”
nor the point that “continuous contact and proximity and carrying may be what infants want but
it might not be what mothers want or more importantly what they can provide” (Hrdy 1999, p.
105), We take such observations seriously and know that translating the research presented in
this volume into "lessons learned" to apply where we can will not be an easy endeavor. But we
are also confident that having a strong, empirically-based beginning point, a baseline
perspective, is the first step in understanding why infants respond and develop as they do. It will
help us understand what can go wrong when estranged or biologically novel, current conditions
push infants beyond their adaptive limits. To lay out a baseline perspective, we begin with our
heritage, what we call here the ancestral context.
The ancestral context
Mobile hunter gatherers (hereafter, hunter gatherers) societies represent a lifestyle that many of
our ancient ancestors are presumed to have followed before the advent of agriculture about 10-
15,000 years ago. Although archeology and paleontology provide important information about
human ancestry, including inheritances from a long line of other animals including non-human
primates, studies of contemporary mobile hunter-gatherers offer glimpses into probable
components of humanity’s past.
Hunter-gatherers are people who gain their sustenance from hunting wild animals and
gathering wild plant materials. Anthropologists commonly distinguish between two categories of
hunter gatherers (Bird-David, 1994; Fry, 2006; Ingold, 1999; Kelly, 1995). One category,
typified by the Kwakiutl of the American northwest coast and the Ainu of Japan, is variously
referred to as collector societies, delayed-return hunter-gatherers, or non-egalitarian hunter-
gatherers. They live in relatively permanent, relatively dense villages located near highly
concentrated sources of food (commonly fish). These societies are generally organized
hierarchically, much like agricultural tribal societies. The other category, which are more
common and are believed to reflects a more basal pattern of social demography, are those
referred to as band societies, immediate-return hunter-gatherers, or egalitarian hunter-gatherers.
When anthropologists refer to hunter-gatherers or to foragers, unqualified, they are usually
referring to this category, and that is the convention used in this chapter and elsewhere in the
volume, along with the clarifying term, hunter-gatherers. The hunter-gatherers described in this
volume fall between the two types as they are foragers but who do some farming and trading.
During the twentieth century, researchers visited and studied dozens of different hunter-
gatherer societies, in various remote parts of the world, some of which had been very little
influenced by western or industrialized contact. Examples of such societies are the Ju/’hoansi
(also called the !Kung, of Africa’s Kalahari Desert), Hazda (of Tanzanian rain forest), Mbuti (of
Congo’s Ituri Forest) Aka (of rain forests in Central African Republic and Congo), Efé (of
Congo’s Ituri Forest), Batek (of Peninsular Malaysia), Agta (of Luzon, Philippines), Nayaka (of
South India), Aché (of Eastern Paraguay), Parakana (of Brazil’s Amazon basin), and Yiwara (of
the Australian Desert). There are good archaeological reasons to believe that these societies have
core patterns similar to those present the predominant way that human beings (Homo sapiens
sapiens) lived for at least 40,000 years before the development of agriculture, and possibly for
much longer (Boehm, 2008). Although these and other hunter-gatherer groups still exist, it
should be noted that the cultures have changed considerably in the last few decades because of
pressures from the outside world.
Although there is much variability among small-band hunter-gatherer societies, they do
share some remarkable similarities. We draw these generalizations from several sources (Lee &
Daly, 1999; Fry, 2006, 2013; Hewlett & Lamb, 2005; Ingold, 1999).
Characteristics shared across groups
Wherever they are found, hunter-gatherer societies display several common characteristics. They
generally live in live in groups of about 20 to 50 people, counting children as well as adults.
Each group shifts terrain as needed to follow the available game and edible plants, but moves can
also be associated with alliance formation and social relationships between groups (Fry 2006,
Gowdy, 1999). At each campsite to which they move, families build, from natural materials,
small, temporary huts, the construction of which usually takes just a few hours. Because the band
moves frequently, material goods beyond what a person can easily carry are burdens, so there is
very little accumulation of property.
Characteristics of hunter gatherers include a companionship lifestyle that involves non-
exclusive (widely shared) intimacy, characterized by sharing of company, food, residence, food
and movement (Bird-David, 1994; Gibson, 1985; Ingold, 1999). Cooperation, sharing and
egalitarianism are common values. To survive, individuals within the group, whether or not they
are kin (and mostly they are not), cooperate intensely in hunting, gathering, caring for children,
and other activities (Kim et al., 2011). They share food and material goods (50-80% on average;
Hewlett, 2013), often following a general rule that nobody in the group should have more than
anyone else. Although each group is an independent entity in which group members make all of
the group’s decisions, boundaries are fluid and there is generally a spirit of cooperation with
nearby groups. Hunter-gatherers also display common childrearing practices which are shared
with old world primates and social mammals generally but have unique features (e.g.,
alloparental care, extensive cooperation, cosleeping beyond childhood, pronounced social
learning; Hewlett, 2013).
Ancestral Childrearing Practices: The Evolved Developmental Niche
The evolved developmental niche (EDN; Narvaez, Wang et al., 2013) for young social mammals
emerged over 30 million years ago and many of the characteristics of that niche remained true
for human beings (Konner, 2010). For young children, the EDN includes natural childbirth,
extensive and infant-initiated breastfeeding, continuous contact and/or proximity to caregivers,
responsiveness to the needs of the child, free play in nature with multiple-aged playmates,
extensive support of the mother-child dyad and multiple adult caregivers (Hewlett & Lamb,
2005; Hrdy, 2009; Konner, 2005, 2010). The outcomes for the presence or absence of each of
these parenting practices have only recently been studied scientifically and results indicate that
not only physiological but psychological wellbeing is affected (Narvaez, Panksepp, Schore &
Gleason, 2013; McKenna et al., 2007; Narvaez, Gleason et al., 2013; Narvaez, Wang et al.,
2013). For example, significant effects on brain development can be observed when
breastfeeding does not occur in the first months of life (Deoni et al., 2013).
Today there are extensive conflicts between human biology and culture patterns (Eaton,
Shostak & Konner, 1988). For example, the emergence of the SIDS epidemic in Western
industrialized societies was driven by the adoption of untested socio-cultural infant care
inventions and their underlying social values: infants sleeping in rooms by themselves i.e.
solitary infant sleep, not breastfeeding, and laying infants prone for sleep (to promote deep sleep)
all proved to be independent risk factors for the sudden infant death syndrome leading to the
deaths of possible as many as a half a million infants (Fitzgerald, 2000). There is no doubt, then
that much harm can be done when evolved developmental patterns are abandoned altogether for
cultural reasons without explorations of the possible functionally damaging impacts these
changes could mean. Is there a core set of needs and practices whose absence impedes
wellbeing? Section 1 addresses this question by focusing on several key features of mammalian
Cultures have shifted over millennia in terms of how much and what kind of support for
child development is provided. On one end are the contexts that more closely follow the human
developmental niche, which are found often among small-band hunter-gatherers. Though
experiencing many ecological and physical hardships, some hunter-gatherer groups experience
greater social wellbeing than most in modern societies (e.g., Everett, 2009). Section 2 will focus
on case studies of these groups.
On the other end are modern parenting practices, most of which have diverged greatly
from the evolved developmental niche for young children. The high social embeddedness, multi-
aged and cooperative lifestyle of hunter-gatherer culture has been replaced, for example, in the
USA with extensive social and age-related isolation and a productivity-focused lifestyle. Instead
of a village of playful companionship support, many children do not experience characteristics of
the EDN for very long, or worse, they are neglected or abused. Felitti and Anda (2005) suggested
that child maltreatment has been experienced by the majority of adults in the USA. Indeed, on
July 11, 2013, three agencies of the US government sent a letter to state child welfare agencies to
alert them about the issue of childhood trauma (USDHHS, 2013). Currently, maltreatment is
affecting approximately 1 million children each year (USDHHS, 2012). Including a focus on the
effects of early maltreatment will give insight into the extreme cases of the childrearing context.
Section 3 will focus on issues of harm and maltreatment.
This volume
Overall the interdisciplinary set of contributors to this volume addresses contexts for
development, with the aim of increasing understanding of basic mammalian, and human,
emotional and motivational needs in varied contexts. In chapters 2 and 3 of this volume,
neurobiological research is reviewed demonstrating what happens to development when young
mammals do not receive beneficial and normative parenting.
In the first section, the needs of mammalian young are addressed. In chapter 2, The
epigenetics of mammalian parenting, Frances Champagne details research on mammalian
mother-infant interactions which suggests that maternal tactile stimulation has a profound effect
on infant neuroendocrine and behavioral development. Among Long-Evans rats, for example,
natural variation in maternal linking/grooming (L/G) of pups, a primary forms of tactile
stimulation during the postnatal period, leads to profound consequences for offspring; those who
receive low compared to high levels of LG have elevated glucocorticoid levels in response to
stress, increased fear reactivity and impaired learning. Moreover, low LG experienced among
female offspring is associated with reduced levels of maternal behavior and increased sexual
behavior in adulthood. Focusing on epigenetic mechanisms, which are factors that can change
the expression of genes without altering the DNA sequence, Champagne provides evidence to
support the hypothesis that maternal touch induces long-term effects on their off-spring’s brain
development and behavior. For example, the experience of low LG leads to increased DNA
methylation of the Esr1 gene during postnatal development, and the persistence of this epigenetic
effect into adulthood renders low-LG female offspring less sensitive to the priming effects of
hormones which normally enhance maternal sensitivity. As such, reduced maternal sensitivity
results in decreased LG toward the offspring reared by low-LG females, perpetuating a cycle of
low maternal care. Implications of the epigenetic effects of early maternal care on child
development and parenting are discussed, including their relevance for human development and
John Bowlby's delineation of the significance of maternal-infant, and infant-maternal
attachment and his generic "perceptuo-motor mechanisms" that "tie" infants and mothers
together are brought to life by the rich, integrative, endocrinological and psycho-biological
framework used by Amanda Dettmer, Stephen Suomi and Katie Hinde. in chapter 3 entitled,
Nonhuman primate models of mental health: Early life experiences effect developmental
trajectories. Using a variety of observational, genetic, and physiological data, the authors
provide multiple examples of new research that explain and interpret the underlying neuro-
hormonal transactions that are affected by, and respond to, the primate infants developmental
conditions. These conditions include deficiencies that require compensatory responses such as
by cortisol, which lead potentially to more fearfulness, increased inhibition, and less play, and,
on the other hand, more favorable environments providing an abundance of maternal and peer-
based social support that produce "confidence" and maximum resilience of individuals if
In the book’s second section contributors explore how those who live in conditions
comparable to patterns common in human evolutionary history care for their children. The level
of access to their informants, and the detailed observations emerging out of their own important
established personal commitments and connections to these communities, reflect the very best of
ethnographic research and methods. The authors have immersed themselves in the practices of a
particular mobile hunter-gatherer society. A focus on hunter-gatherer contexts can assist us in
discerning the range of what is normal or how questions concerning what is optimal social
development might be developed (in contrast to the dominant focus in science on members of
Western, Educated, Industrialized, Rich and Democratic societies; Heinrich et al., 2009).
Examining the details of several small band hunter gatherer societies regarding parenting,
sleeping arrangements, personality, social relations and morality (and the interconnections) can
offer insights into how these factors relate to one another and may influence children’s
development in hunter-gatherer societies.
In chapter 4, Relationships in a world of uncertainty: qualities of social life of Efe hunter-
gatherer infants, Gilda Morelli, Paula Ivey Henry, and Steffen Foerster describe the social
landscape and development of Efe infants and toddlers. The Efe are pygmy hunter-gatherers in
the Ituri forest, in the northeast portion of Africa’s Congo River Basin. Their world is one of
uncertainty. Reliable access to nutritious foods is unpredictable, and reliable access to the same
people day-to-day is not assured. Diseases can strike any time, and it is not uncommon for
parents to die before their children are grown. For the Efe, survival depends on sharing and
cooperation with others beyond the immediate family (a trait that seems unique to humans) that
is built on a history of trustworthy experiences. Morelli and her colleagues present narrative and
empirical data showing how Efe infant relationships and trust develop in a highly variable
ecology. Efe infancy is intensely social. Infants experience an active social network from birth,
and prior research shows that they may be nursed by other women, not just their mothers.
Infants and toddlers are in near constant physical and/or social contact with people for much of
their waking time. They move from partner to partner at rates of roughly once every 3 minutes;
and flexible as people move in and out of the camp. These young children are very successful at
obtaining resources from other members of the forager band, as well as visitors. At all ages
children experience highly positive affect and reward their partners’ engagement with smiles,
laughter, and bright-eyed attentiveness. With increasing growth and mobility, toddlers play a
more active role in determining with whom they spend time, and their networks grow and
diversify, most likely, as a result. Children are active, not passive partners in developing the
trusting relationships that are essential to survival in such an uncertain world.
In chapter 5, Batek childrearing and morality, Kirk and Karen Endicott report on their
research in the mid-1970s with the Batek people of Malaysia who largely followed a nomadic
hunter-gatherer lifestyle but also traded forest products for cloth, metal goods and some food
commodities. The Endicotts’ description of childrearing practices through adolescence give a
window into how these practices influence the personality of the adults and the culture generally.
They describe socialization into non-aggression. For example like all toddlers, Batek children
show signs of aggression or possessiveness but adults generally react minimally, usually gently
redirecting them or using humor to relieve tension. The adults seem to have an understanding
that the child will grow out of these impulses and indeed they do without punishment or
admonition. Older children are scared into staying close to camp with threats, as in many
cultures, that a bogey man might come if they do not comply with certain rules. In late
childhood and early adolescence, children move into spending more time on sex-typed activities
(gathering or hunting with the adult of the same sex). Adolescents set up their own households
with each other, not under the direction of adult guidance, until they enter real marriages. Adults
generally display enthusiasm, a “confident independence,” a sense of responsibility to others,
and a “cooperative autonomy,” with no apparent personality differences between males and
Barry Hewlett and Jennifer Roulette's pioneering study of the social sleeping patterns and
arrangements of juveniles, adolescent and teens, described in Chapter 6, Cosleeping beyond
infancy: culture, ecology, and evolutionary biology of bedsharing among Aka foragers and
Ngandu Farmers of Central Africa, amongst two well-studied farming and foraging peoples
living adjacent to each other in Central Africa reminds us of just how far Western cultural
ideologies have departed from our species-wide, universal practice of mothers and children
cosleeping (in some form) with infants breastfeeding throughout the night but older children
never sleeping alone. Indeed, throughout the world most parents would never even imagine the
possibility of their infants or children sleeping outside of their company, protection and /or social
reach of their alloparents defined either by kin, relationships through marriage, personal
preferences and/or friendships.
In section three, broader questions about evolution, family, children and human nature
are the focus. In The Environment of Evolutionary Adaptedness, rough-and-tumble play, and the
selection of restraint in human aggression, Douglas Fry addresses the evolution of aggression
restraint. Evolution has favored non-lethal aggression in intraspecific competitive interactions in
many species. Intraspecific aggression that causes significant harm is rare among animals,
including humans in nomadic foraging conditions, and when it occurs it is a personal, not
collective, action. Instead displays of aggression between group collectives cause little physical
harm and are characterized by drama and preservation of face. Fry discusses how rough-and-
tumble play may be critical for learning aggression restraint because it provides a platform for
learning vital social skills such as the signaling of intentions and maintaining a playful, non-
injury-inducing interaction. It provides a way to establish dominance without serious injury.
In chapter 8, Peter Gray presents a Play theory of hunter-gatherer egalitarianism. His
thesis is that our hunter-gatherer ancestors used play, more or less deliberately, to counteract the
tendency to struggle for status and dominance, which was inherited from our primate ancestors,
and that this permits the high degree of cooperation and sharing that hunter-gatherer life require.
He explains that play, in all mammals, requires a temporary setting aside of aggressiveness and
dominance, and he reviews research suggesting a negative correlation, across primate species,
between adult playfulness and steepness of dominance hierarchies. Then, for the rest of the
chapter, he reviews research on contemporary hunter-gatherers showing how their social life
including their games and dances, religious practices, approach to productive work, means of
enforcing social norms, and approach to children’s education—is imbued with the spirit of play.
The hunter-gatherer culture represents a social landscape where play and humor are valued and
aggression and status seeking are devalued.
In chapter 9, Incentives in the family I: The family firm, an evolutionary/economic theory
for parent-offspring relations, Joan Roughgarden and Zhiyuan Song challenge the received view
of parent-offspring behavioral conflict with its emphasis on psychological manipulation by
offspring of parents for the purpose of getting their needs met (and advancing their genetic
fitness). Instead, derived from a social selection model, they emphasize honest communication of
needs within the relationship, with a shifting balance of incentives in a type of family “team
play.” Their cooperative theory better fits the parent-child behavioral data and the social
harmony that is found in small-band hunter-gatherer societies.
In chapter 10, Preliminary steps towards addressing the role of non-adult individuals in
human evolution, Agustin Fuentes proposes a reconsideration of children in evolutionary theory.
Children are often absent, or underrepresented, in our reconstructions of human behavioral
evolution. However, there are emerging indications that we can envision non-adults as having
substantive impacts in the ways in which early humans interfaced with local ecologies and each
other. Modern evolutionary theory provides a toolkit for conceptualizing the role of children in
human evolution, especially in the context of niche construction. Through broad cooperation that
includes behaviors such as alloparenting, materials collection and transport for tool making,
immatures may have played a critical role, Fuentes suggests that we consider the possibility that
immatures (children) are actors alongside adults in creating and shaping the social and ecological
inheritance systems that enable behavioral flexibility and extended adaptation. Active
participation by children may have been one of the key factors in the long-term success of the
genus Homo.
In section four, issues of changed childrearing contexts are addressed including trauma
and abuse. Chapters 11 and 12 describe the extremes for human development, when parents
themselves are troubled and unresponsive. In chapter 11, Child maltreatment and early mother-
child interactions, Kristin Valentino, Michelle Comas and Amy Nuttall provide a developmental
psychopathology perspective on mother-child interactions among maltreating and nonmaltreating
families from infancy through toddlerhood, addressing how a maltreating family environment
affects developmental outcomes. Because child maltreatment represents an extreme deviation
from the average expected early caregiving environment, the comparison of maltreating and
nonmaltreating families serves as an experiment of nature and provides critical information
regarding the contribution of early caregiving to young children’s development. In particular,
early maltreatment is associated with attachment disorganization, decreased maternal sensitivity,
and decreased maternal verbal interactions. Moreover, infants and toddlers from abusing families
demonstrate persistent deficits in social initiation and autonomous behavior compared with
children from neglecting and nonmaltreating families, which underscores the disruption in
normative social development associated with an abusive family context. The authors conclude
by providing specific examples of translational research interventions for young maltreatment
children informed by basic research on mother-child interactions during early childhood.
In chapter 12, The importance of the developmental perspective in evolutionary
discussions of PTSD, Robyn Bluhm and Ruth Lanius critique theoretical and evolutionary
accounts of mental disorders, with an emphasis on posttraumatic stress disorder (PTSD).
Focusing on chronic exposure to traumatic stress during early life (i.e., persistent childhood
abuse), Bluhm and Lanius present data which demonstrates how early childhood trauma disrupts
neural development, and they argue that several key deficits observed in patients with PTSD
subsequent to early childhood trauma can be understood via these alterations to neural
development and functioning. Thus, in contrast to current theoretical accounts of PTSD, which
have largely ignored early life trauma, an alternative account that emphasizes the developmental
context is presented.
Eugene Halton in Chapter 13, Presymbolic interaction: Genetic dictates and
protosymbolic communication, takes a sweeping view of human evolution. Considering the
development of self and the pervasive role of symbol and meaning in human evolution, he
reviews the contexts of early development and hunter-gatherer practice, contrasting it with the
modern world and highlighting how media and technology act as contemporary socializing
agents. Social media and technology have taken such a dominating influence in socialization
that they can be viewed as inversions of evolutionarily central socializing practices. In this
chapter Halton lays out how contemporary techno-consumption culture mimics aspects of our
behavior and perception related to evolutionary processes, yet subverts their action and
The final chapter in the book, Childhood environments and flourishing, by Tracy Gleason
and Darcia Narvaez, considers childhood environments and their relation to child flourishing,
incorporating the insights from volume chapters. It is still unclear which biological needs are
particularly essential for optimal development, although attending to 30 million years of evolved
practices might be a place to start as a baseline for examination. The quality of the early
caregiving context has significant ramifications for later physiological and psychological
functioning. Central to this nurturing environment is the responsivity of the primary caregiver,
and provision of adequately sensitive social and emotional care associated with many positive
outcomes. However, flourishing, defined as emotional, psychological, and social wellbeing,
along with appropriate physiological regulation, and a sociomoral orientation towards others,
might require an intense level of caregiving on the part of the community that is atypical in the
USA. Attention to caregiving practices common among small-band hunter-gatherers behaviors,
which are positively associated with sociomoral development, as well as to the broad social
context of early development might provide important steps toward creating proactively moral,
prosocial communities.
The interdisciplinary set of contributions provides insight into human development, broad and
particular cultural customs, as well as evolutionary features of social structure in light of human
evolution. The integration of eclectic methods and theories break previously existing traditional
disciplinary boundaries separating anthropology, psychology, sociology and neuroscience. As a
result of cooperative research efforts by scientists from different fields each discipline is in a
strengthened position and finding answers to questions that a single discipline working alone
even knew were important to ask.
The shifting baselines for childrearing which have occurred over generations in settled
societies may have longterm effects on the psychology, anthropology and sociology of
subsequent generations. Social environments consistent and inconsistent with ancestral
conditions may have longterm effects on individual outcomes. The cultures of mobile hunter-
gatherer societies examined here may offer a glimpse at the contexts for child flourishing. With
the information provided by these scholars, we may be in a better position to understand what
optimal childrearing entails and thereby be able to facilitate changes in social structures and
support systems that better foster wellbeing in human development. This next step, however
challenging, will require understanding that our evolutionary legacies are relevant to helping us
adjust our lifestyles to provide a fit between our more conservative biology and cultures that can
be at odds with one another to greater or lesser degrees. Only our imaginations are stopping us.
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... A newborn sibling's arrival may have been problematic for infants due to features of the EEA that pertained to its social composition (Simpson, 1999;Simpson & Belsky, 2016) and scarcity of parental resources (Trivers, 1974). It has been estimated that our evolutionary ancestors were hunter-gatherers who lived in small bands of only 20 to 50 individuals, including children (Eibl-Eibesfeldt, 1989;Narvaez, Gray, McKenna, Fuentes, & Valentino, 2014). Due to low population density, it was likely that an infant's mother was the sole lactating female in the clan, and due to harsh living conditions, her supply of breast milk was adequate for sustaining only one child at a time. ...
... It is estimated that approximately half of all children failed to survive childhood (Volk & Atkinson, 2013). These data are comparable to those which are evident in a number of extant societies, where habitats approximate those of our evolutionary past and where individuals liv-ing in nomadic bands, foragers in particular, do so in a manner that is thought to be consistent with that of our evolutionary ancestors (McDade & Worthman, 1998;Narvaez et al., 2014;Volk & Atkinson, 2013). In these settings, toddlers are placed at exceptionally great risk when a sibling's birth occurs following a short interbirth interval (Dyson, 1977;Hobcraft, McDonald, & Rutstein, 1983). ...
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This paper theorizes on the constructs of jealousy and infant-caregiver attachment by proposing a synthesis that bridges parent-offspring conflict theory (POCT; Trivers, 1974) with the evolutionary-ethological theory of attachment (Bowlby, 1969). Following Bowlby, we recognize attachment as an adaptation to threat to infant survival in ancestral settings. However, departing from his focus on environmental danger as the source of threat, we draw on Trivers’ understanding of siblings as competitors for parents’ scarce and finite resources, and propose that attachment was compelled by threat posed by the birth of a sibling. In support of this synthesis, we present evidence that illuminates infants’ need for exclusivity in the infant-maternal relationship, and elaborate on the origin of that need as a function of the benefits of exclusivity to infant survival. We also present evidence that infants’ defense against usurpation, jealousy protest, resembles attachment behavior, specifically separation protest, in terms of the specificity of the context in which it is presented, its direction and affective tone, the timing of its onset, and pattern of individual differences. The fact that both jealousy protest and separation protest occur at approximately 9 months of age, which is the juncture when a sibling’s birth is possible, suggests that both forms of protest were compelled by inevitable consequences of a sibling’s birth, namely, sibling competition for parental resources and mother-initiated separation. We argue that as a recurrent and universal event that presaged threat of both usurpation and separation, the birth of a sibling represents the ultimate foundation of attachment.
... Hunter-gatherer societies provide useful parenting benchmarks in today's complex society characterized by socio-cultural norms influenced by the process of globalization and the normative aspects of the fundamental principle of the best interests of the child. Some of the parental practices of hunter-gatherer societies, conceptually embedded in hunter-gatherer childhood, correspond to the recommendations of contemporary psychologists and normative requirements for respect of children's rights (Chaudhary & Swanepoel, 2023;Narvaez et al., 2014;Bjorklund, 2021). For example, in the critical period of early childhood development and for an optimal attachment bond with family members, fundamentals are proven to be: affectionate behaviours and physical contact between mother or other adult caregivers, co-sleeping method (sleeping in the same room or in the same bed with parents), breastfeeding on demand and for periods longer than six months, continuous responsiveness to the child's biological needs before or immediately after the onset of signs of discomfort, and prioritizing engagement in communication or interactive and stimulating play. ...
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There are numerous reports on the subjecting of children to various forms of violence as a disciplinary method throughout history, from ancient to modern times. Punishing children using physical violence, as a method of acquiring compliance with various social norms dictated by adults, has been continuously practiced during recorded humanity. The current international standards on children’s rights that require protection against violence have emerged in the past few decades as a societal response to the quasi-universal use of corporal punishment in modern societies. By contrast, in their empirical fieldwork done since the XIXth century in many hunter-gatherer societies, the ethnographers have found that most of these societies are characterized by the absence or the exceptional use of corporal punishment against children. In this regard, one area of interest consists in the significant differences in child discipline between hunter-gatherer and agrarian societies. Therefore, this analysis aims to explore variations in parental attitudes towards child-rearing in these two types of small-scale societies, integrating a historical perspective and taking into account variables such as indulgence towards children’s behaviour, responsiveness to children’s needs, affection towards children, children’s autonomy, father involvement and their correlations with the absence or presence of corporal punishment. For ethnographic information, I used Yale University’s eHRAF database, from which 601 ethnographic texts on 139 small-scale societies (85 hunter-gatherer societies and 54 agrarian societies) were extracted, coded, and analysed. Interpretation of the data indicates that hunter-gatherer societies have positive, non-punitive, and more responsive parenting approaches to children’s needs, lacking physical punishment, while agrarian societies have scores indicating the presence of violent methods of discipline and parenting practices focused on submission and punishment. All five parental attitudes included in the analysis scored higher in egalitarian societies than in agrarian ones. The most pronounced disparity between the two types of cultures is related to the indulgent nature of parental care. In addition, attitudes of emotional neglect and reduced expression of affection towards children and limited father involvement in child rearing correlate very strongly with the choice of physical punishments for child discipline. The findings of this analysis highlight the importance of considering the historical and cultural context of parent-child interactions and cultural determinants in choosing positive parenting methods and provide a historical-anthropological perspective for promoting the normative prohibition of all forms of violence against children.
This chapter offers evolutionary developmental psychology models of caregiving and attachment as species-wide features of infant–maternal relationships. We explain that 3 years of breastfeeding were compelled by the leading causes of infant mortality in ancestral settings—infection and malnutrition-related disease—and discuss how it underpinned lactation-based caregiving and a biobehavioral bond, lactation-based cohesion, with fitness payoffs for infants: (1) protection against malnutrition and morbidity; (2) preservation of the inter-birth interval (IBI) as a haven against competition with a newborn sibling; and (3) psychological benefits of steady and enduring exposure to a profoundly satisfying manner of proximal contact with a caregiver. We theorize that lactation-based caregiving and cohesion satisfied infants’ physical and psychological needs, and in doing so laid the foundation of a psychological adaptation, child-to-mother attachment, an affectional bond able to withstand being untethered to lactation by infants’ third year. The timing of the transition from lactation-based cohesion to attachment coincided with attenuated dependence on breast milk due to maturation of infants’ digestive and immune systems, and with the eruption of infants’ molar teeth, which prompted mothers to bring breastfeeding to conclusion. At this juncture, mothers transitioned to caring for weanlings (rather than nurslings), which meant an end to maternal caregiving being upheld by biobehavioral features of lactation. We argue that absent such support, the costliness of caregiving of weanlings compelled an adapted psychological mechanism, mother-to-child attachment, defined as an affectional bond between ancestral mothers and their former nurslings that was anchored in 3 years of lactation-based caregiving and cohesion.
In this chapter, nascent jealousy is theorized as a psychological adaptation to the threat of usurpation by a newborn sibling that ancestral infants could have encountered by the age of 9 months. This nature of threat is explained in terms of ancestral infants’ dependence on their mothers as their sole sources of breast milk, which was required for survival. We discuss how the need for exclusive access to mother for breast milk coevolved with expectations of exclusivity in the infant-maternal relationship and with exquisite sensitivity to violations of those expectations that, over deep time, shaped nascent jealousy and its expression through jealousy protest as a mechanism for protecting against usurpation. Next, jealousy protest is discussed in relation to separation protest. Commonality between the two patterns of protest and the overlap in timing are interpreted as the basis for conceptualizing infant-maternal attachment as an adaptation to usurpation. Distinctions are informed in terms of the adaptive advantages of exclusive (vs. nonexclusive) proximal contact with mother. Finally, we address milestones in socioemotional, social cognitive, and motor development that occur at 9 months. We explain how jealousy protest was enabled, not only by attachment formation for its role in establishing a valued relationship but also by skills in cognition and locomotion that facilitated infants’ abilities to recognize and manage usurpation. We propose that these milestones originated in tandem at 9 months to help prepare infants for potential challenges of usurpation as they entered toddlerhood.
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From the back cover: "Are babies divine, or do they have the devil in them? Should parents talk to their infants, or is it a waste of time? Answers to questions about the nature and nurture of infants appear in this book as advice to parents in seven world societies. Imagine what Dr. Spock might have written if he were a healer from Bali...or an Aboriginal grandmother from the Australian desert...or a diviner from a rural village in West Africa. As the seven "child care manuals" in this book reveal, experts worldwide offer intriguingly different advice to new parents. 'A World of Babies' brings alive infant care practices around the world in the form of baby and child care manuals "written" by members of seven real societies. The information, while presented in an imaginative fictive format, is based on extensive research by anthropologists, psychologists, and historians. Encountering fascinating facts about how people in other societies view and raise their babies, readers may be led to see the beliefs and practices of their own society from a new perspective. The creative format of this book brings alive a rich fund of ethnographic knowledge, vividly illustrating a simple but powerful truth: there exist many models of babyhood, each shaped by deeply held values and widely varying cultural contexts. After reading this book, you will never again view child-rearing as a matter of 'common sense.'"
The field of cognitive psychology is in a state of empirical abundance, and experts now know more about mammalian brain function than ever before. In contrast, psychological problems such as ADHD, autism, anxiety, and depression are on the rise, as are medical conditions such as diabetes, obesity, and autoimmune disorders. Why, in this era of unprecedented scientific self-knowledge, does there seem to be so much uncertainty about what humans need for optimal development? Evolution, Early Experience and Human Development asserts that human development is being misshaped by government policies, social practices, and public beliefs that fail to consider basic human needs. In this pioneering volume, scientists from a range of disciplines theorize that the rise of problems like depression and obesity is partially attributable to a disparity between the environments and conditions under which our mammalian brains currently develop and those in which the brains of our distant ancestors developed-and evolved to suit. These early environments and conditions have been named the environment of evolutionary adaptedness, or EEA. For example, healthy brain and emotional development depends to a significant extent on caregiver availability and quality of care, which is argued to be in decline by some experts; in addition, practices such as breastfeeding, cosleeping, and parental social support, which have waned in modern society, may be integral to healthy infant development. As the authors argue, without a more informed appreciation of the ideal conditions under which human brains develop and function, human beings will continue to struggle with maintaining mental and physical health, and psychological treatments will not be effective. Evolution, Early Experience and Human Development puts forth a logical, empirically based argument regarding human mammalian needs for optimal development, based on research from anthropology, neurobiology, animal science, and human development. The result is a unique exploration of evolutionary approaches to human behavior that will support the development of new policies, new attitudes toward health, and alterations in childcare practices that will better promote optimal human development.
Are babies divine, or do they have the devil in them? Should parents talk to their infants, or is it a waste of time? Answers to questions about the nature and nurture of infants appear in this book as advice to parents in seven world societies. Imagine what Dr. Spock might have written if he were a healer from Bali…or an Aboriginal grandmother from the Australian desert…or a diviner from a rural village in West Africa. As the seven "child care manuals" in this book reveal, experts worldwide offer intriguingly different advice to new parents. A World of Babies brings alive infant care practices around the world in the form of baby and child care manuals "written" by members of seven real societies. The information, while presented in an imaginative fictive format, is based on extensive research by anthropologists, psychologists, and historians. Encountering fascinating facts about how people in other societies view and raise their babies, readers may be led to see the beliefs and practices of their own society from a new perspective. The creative format of this book brings alive a rich fund of ethnographic knowledge, vividly illustrating a simple but powerful truth: there exist many models of babyhood, each shaped by deeply held values and widely varying cultural contexts. After reading this book, you will never again view child-rearing as a matter of "common sense." Judy DeLoache is Professor of Psychology at the Beckman Institute for Advanced Science and Technology at the University of Illinois at Urbana-Champaign. Alma Gottlieb is Professor of Anthropology at the University of Illinois at Urbana-Champaign.
There is now ample evidence from the preclinical and clinical fields that early life trauma has both dramatic and long-lasting effects on neurobiological systems and functions that are involved in different forms of psychopathology as well as on health in general. To date, a comprehensive review of the recent research on the effects of early and later life trauma is lacking. This book fills an obvious gap in academic and clinical literature by providing reviews which summarize and synthesize these findings. Topics considered and discussed include the possible biological and neuropsychological effects of trauma at different epochs and their effect on health. This book will be essential reading for psychiatrists, clinical psychologists, mental health professionals, social workers, pediatricians and specialists in child development.
Two cultural constructs pervade the social life of the Buid of Mindoro, Philippines. The first, which I label 'companionship', is based on the sharing of food, labour and sex, and is associated with the dominant values of equality and autonomy. The second, which I label 'kinship', is based on shared physical and spiritual substance, and is associated with negatively valued tendencies towards domination and dependency. I investigate the symbolism surrounding these two constructs, and its articulation with gender and mortuary symbolism, before turning, in the conclusion, to the implications of this ethnography for the cross-cultural comparison of kinship as a symbol of moral values.
This article offers a fresh account of the social organization of hunter-gatherers, challenging the ecological framework which has dominated hunter-gatherer studies to date. It re-visits the conversation on `band societies', which was started by Julian Steward in 1936 and nearly died out thirty years later, afte the seminal symposium Man the Hunter. It introduces indigenous voices into it, linking them not with ecological but with contemporary theoretical concerns about the diversity of sociality and about society as a concept. The article proposes that band relationships are about ways of relating to others that rest on 'we relationships' and on a 'sharing perspective'. They are expressions of sociality, the general significance of which has hitherto been largely overlooked.