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Communicating cooperative intentions drove the selection of collective ritual in hominins

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Communicating cooperative intentions drove the
selection of collective ritual in hominins
Radek Kundt & Martin Lang
To cite this article: Radek Kundt & Martin Lang (2023): Communicating cooperative
intentions drove the selection of collective ritual in hominins, Religion, Brain & Behavior, DOI:
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Published online: 24 Jul 2023.
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Communicating cooperative intentions drove the selection
of collective ritual in hominins
Radek Kundt and Martin Lang
LEVYNA: Laboratory for the Experimental Research of Religion, Masaryk University, Brno, Czech Republic
1. Introduction
We are grateful to all commentators for their engagement with our article and insightful comments.
Though generous, the target articles word limit was quite constraining for our vast interdisciplinary
endeavor. Where we originally had a page, we had to end up with a paragraph. Where we started
with a paragraph, we had to nish with a sentence. We had to apply the same economic approach
to the cited works arriving at one where ten would be more appropriate. We feel that this brevity
caused several misunderstandings, and we are grateful that we can use this response to clarify and
explain some of our propositions in more detail.
In doing so, we tried to avoid strawman arguments, and whenever we refer to the commentators
by name, we only address their expressed positions. However, where we felt inspired by hints and
crumbs they left along the way of their main arguments, we also tried to create fully-blown versions
of the possible alternative standpoints from these hints. We do this for the sake of the argument as it
allows us to venture beyond the scope of the original objections to other important/relevant topics.
These extensions are ours alone and should not be taken necessarily as commentatorspositions.
For readerscomfort, we organized the critical commentaries and our responses to match the
outline of the target article and serve as an addendum to each section.
2. The form and function of collective ritual
None of the commentators took direct issue with our denition of ritual based on its formal and
structural aspects. However, since Fischer used festival-like activities such as dancing plagues as
an example of rituals that have other-than-signaling function, we feel that our form-based
denition of collective ritual needs some clarications. That is, we would not consider such festi-
val-like activity an instance of collective ritual. Festivals are often too unstructured and chaotic
(i.e., allowing too much of expressive freedom in dancing, singing, and/or other performative
acts) to meet our Rappaportian criteria of invariant acts and utterances not encoded by the per-
formers themselves.Similarly, we would not consider music a collective ritual either (which
both Fischer and Alcorta seem to suggest). Of course, in festivals and music events, as in all
human activity, a continuum of formality, scriptedness, and repetition exists. In this respect,
when a phenomenon is formalized enough to be recognized as a ritual is a matter of operational
denition: for us, rituals would be closer to the extremes of formality, scriptedness, and repetition.
Crucially, rituals also involve a high degree of coding by previous generations,which are again
often lacking in other cultural events.
The issue of cost relativity raised by Fischer could also be casted as a denitional problem.
Fischer correctly notes that there are reverse situations when pain is perceived as rewarding and
that, for example, boredom might cause inaction to be costlier than action. We agree that the
© 2023 Informa UK Limited, trading as Taylor & Francis Group
CONTACT Radek Kundt
assessment of costs must be well embedded in the organism`s socio-ecology as well as cultural con-
texts (Lang & Kundt, 2020). However, the broader relativization inferences Fischer makes using
these examples do not hold ground.
First, Fischers relativization treats exceptions to the rules and by-products of the standard func-
tioning of mechanisms as if they were the rules and the standard products themselves. To use the
example of pain, the capacity for pain is of great adaptive signicance to organisms, and the phy-
logeny of pain mechanisms, though complex, is well understood (Nesse & Schulkin, 2019). The
main selective advantage lies in the motivation to avoid situations causing tissue and joint damage,
as demonstrated by the tragic results of syndromes of pain deciency (Nagasako et al., 2003).
Importantly, humans use pain indices in communication with others, either as a signal to elicit
care (Steinkopf, 2016) or practical help with escape, recovery, and healing (Williams, 2002),
suggesting that people are well-equipped to recognize others in pain. Many collective rituals world-
wide involve relatives who witness their close ones undergoing painful ordeals (e.g., rewalking,
sword climbing, and self-whipping). Some initiations even include parents facilitating and observ-
ing genital mutilation of their children. We believe it is not controversial to assume that these rela-
tives do not rejoice in seeing their loved ones suer. Moreover, if the pleasure mechanism would be
the sole driver of ritual suering, it is unclear why those practices would be embedded in normative
systems often regulating interpersonal behavior. That is, we should expect to observe groups of ran-
domly assorted lovers of pain perform their rituals (such as people gathering at a music event)
rather than rituals that are deeply meaningful for specic communities. While such communities
of pain lovers can and do exist, they are in the extreme minority compared to painful rituals
embedded in normative frameworks. Thus, we believe that our explanation of painful rituals is
more parsimonious as it holds across most painful rituals.
Second, Fischers suggestion treats the outputs of a specic mechanism as if they should automati-
cally be informative about the functions of the mechanism and the reasons behind its selection. How-
ever, we need to be wary of the trap of the Panglossian adaptationism Gould and Lewontin tried so
vehemently to guard us against (1979). Gould and Lewontinscritiquewasmainlyconcernedwiththe
pitfalls of treating something as an autonomous trait when it might be only a non-functional conse-
quence of natural selection operating on other traits. The same logic applies here, too. Mechanisms
that support our adaptive traits might have many quirks depending on the complex path-dependent
operation of natural selection. Some of these quirks might play a part in the adaptive function of the
mechanism (e.g., increasing the sensation of pain stimuli if it often repeats and untreated might
accumulate to a bigger problem) or may point to the main function of the mechanism (e.g., the
fact that hypersensuality to pain is far more common than congenial loss of capacity for pain) whereas
some may not (e.g., pleasure with the onset of pain). As long as the sum of these quirks provides, on
average, the adaptive advantage, they are all part of the initial overall solution to the original selective
pressures. Treating each of them separately as if they were individually selected for can easily lead to
false scenarios of selective pressures that never existed and to functions that never were functions in
the rst place, only consequences of forces shaping other functions.
To be fair, the overall tone of Fischeŕschallenge to our adaptationist account is on the side of
caution Gould and Lewontin called for. We appreciate this reminder and note that to safeguard
ourselves against excessive adaptationism in the target article, we aimed to specify a complete
path to a trait from multiple angles and, whenever possible, in all four of Tinbergeńs dimensions
(1963). Relying on such safeguarding rules is one way to overcome the challenge of multiple
mechanistic products that may all account for the evolution of that mechanism (Kundt, 2018).
In a similarly critical vein, Brusse thoroughly reviewed our conceptualization of commitment
signals and argued that the evolutionary pathways we outlined are unlikely to be adaptive. That
is, he argues that commitment signals were unlikely to aect biological tness. Again, we believe
that the confusion partially stems from our brevity in the main paper, and we are grateful for
the opportunity to expand on our argument. We agree with many of Brusses remarks. The appli-
cation of costly signaling theory to human signaling is challenging and in need of much further
scrutiny. However, we would like to maintain that commitment signals are an adaptation, albeit
much more complex than other costly signals in humans and non-human animals.
In contrast to the hidden traits of non-human animals and some human traits (such as strength),
human cooperative intentions are not hard-wiredto the intensity of signals. While the length of
the male barn swallows tail feathers is directly associated with its genetic quality, and the individual
has limited means to aect this length (Searcy & Nowicki, 2005), human cooperative signals can
often be broadcasted by low-quality signalers. Moreover, it is not clear what the hidden trait should
refer to in the case of human cooperative intentions: unrestricted cooperation, altruism, or paro-
chial cooperation? In other words, people need to be exible and selective with whom they want
to cooperate. With some groups, they may want to free-ride despite cooperating in other contexts.
Therefore, it might be more appropriate to talk about strategiesthat are being signaled in the case
of human cooperative communication rather than underlying traitswhen describing peoples
hidden cooperative qualities (although, some people are, of course, more cooperative on average
than others; Lang et al., 2022).
One implication of this human signaling exibility is that the individual decision to signal needs
to be computed based on the expected costs and benets of the commitment signal, both estimated
with certain probabilities. This is the crux of our argument. While non-human animal signaling
models usually assume dierential costs based on dierent types (Grafen, 1990), human signaling
must assume dierential costs and benets that are, moreover, estimated based on an individuals
predispositions, social learning, experience, and cultural context. It is in the computation of these
estimates that we see a potential for dierential assessment of signaling trade-os by people playing
cooperative and selsh strategies because neither the costs nor the benets (and their probability)
are easily quantiable.
In a recent paper, Lang and colleagues (2022) showed that people playing cooperative strategies
were more likely to send a costly commitment signal to play a public goods game with other sig-
nalers and that people playing selsh strategies estimated the potential benets of the costly com-
mitment signal more negatively. That is, costly commitment signals that directly referred to
cooperative norms were successful in assorting co-operators. Despite this result, Brusses argument
that free-riders should invade these imperfect signaling systems and destroy them in the long run is
a valid objection to our model. However, since each free-rider needs to overcome their implicit cog-
nitive biases in estimating the cost and benets of the commitment signal, we argue that free-riders
would not often fake signals. These biases would be even more prominent during intense selective
pressures when free-riding might mean a direct risk of life (e.g., free-riding during community
defense; see Lang et al., 2023 for an experimental support of this claim). Finally, the infrequent
free-riders, although successful, do not constitute a large problem for the evolution of signaling sys-
tems because these systems can be stable if signals are honest on average (Johnstone & Grafen,
1993), similar to mimics of toxic animals that can be sometimes eaten by predators without destroy-
ing the adaptive advantage of mimicking.
The crucial question that we are currently intensively researching is how those cognitive biases
might arise and operate, testing between a dual-process model (Greene, 2017), a social projection
model (Krueger, 2013), and a social heuristic model (Rand, 2016). While the rst model may be the
closest to the original costly signaling theory by suggesting that co-operators bypass the compu-
tation of signal costs and benets due to a less exible link of cognitive processes to genetic quality,
the second model assumes that when people lack available information about others, they project
onto others their computations (hence, free-riders would not trust that co-operators will cooperate
in the signaling group). The third model is the closest to what we presented in the target article
because it crucially relies on social learning during ontogeny (socialization). If a person grew up
in an environment where commitment signals were repeatedly functional, computing costs and
benets may be again by-passed by co-operators while a sign of this computation (e.g., by musing
about whether to send the signal or not) would immediately reveal free-riders (Jordan et al., 2016).
Arguably, this is a partial hybridization of the costly signaling model with CREDs by including
social learning (Chvaja & Řezníček, 2019), yet we believe that it is applicable even to the early dyadic
commitment signals (where social learning would happen within the dyad). By the same token, this
type of socialization need not be religious, although we agree that religious sanctication of com-
mitment signals plays an important role in their stability and may be more functional than secular
rituals (Chvaja et al., forthcoming; Shaver et al., 2018). Finally, it may seem at this point that if we
assume repeated interactions, costly commitment signaling may be unnecessary because co-oper-
ators would assort using direct and indirect reciprocity (Trivers, 1971). As we argued in the target
article, costly commitment signals would still be important (and especially so) during high-stakes
cooperative endeavors such as collective hunts or warfare (Lang et al., 2023; Sosis et al., 2007) where
one-shot defection might be deadly for those who remained.
3. When ritual evolved: cooperative signals in non-human animals
Alcorta and, to some extent, Kalan critique our model for putting too much emphasis on human
exceptionalism. We acknowledge that this critique is partially correct but would like to caution
against enthusiastic projections of human traits on other non-human animals as well as against
sweeping cross-species comparisons (e.g., see a recent meta-analysis failing to nd the previously
claimed presence of inequity aversion across species: Ritov et al., 2023). As a matter of fact, we
fully share Alcortas and Kalans view that human exceptionalism is thinning day by day with excit-
ing new data coming in. This position was also a starting point for our project: searching for a con-
tinuum of human and non-human primate cooperative communication. However, we decided to
be conservative in our claims and estimates to counter our potential biases and expectations. Basing
our inference only on well-established evidence helped us to construct our case on the least specu-
lative foundations. Looking at our model through this conservative lens, we often found only weak
evidence for cooperative communication in non-human primates, tilting the evidential weight
toward human exceptionalism. The resulting tilt in our interpretation does not mean that the
behavioral patterns and mechanisms we identied cannot be found in non-human animals. As
Alcorta argues, they can be identied, but we must be careful about such cross-species
For example, Alcorta marshals evidence from various species (e.g., humpback whales, songbirds,
or bonobos) to argue that these species use social learning in signal transmission and production.
We do not doubt that social learning plays this role in other species and are happy to talk about, for
instance, humpback whale culture in this respect (Laland, 2017). Nevertheless, such cross-species
comparisons need to be strongly supported by phylogenetic analyses showing these phenotypes
are either synapomorphies (which seems unlikely given the phylogenetic distance between birds
and mammals) or products of convergent evolution. Showing that the seemingly similar pheno-
types are products of convergent evolution, that is, have the same function and result from the
same selective pressures, is a mammoth task replete with various inferential risks (Agrawal,
2017; Blount et al., 2018). Species may evolve the same phenotype under dierent selective press-
ures, dierent phenotypes responding to the same selective pressure, or have seemingly similar phe-
notypes that serve dierent functions (Losos, 2011). Although some of the phenotypes we identied
as essential for the evolution of ritual behavior in hominins may be shared with dierent species,
such a claim would need to be bolstered by a broad phylogenetic analysis that vastly exceeds the
goal of our original model.
To counter the risk of overinterpreting available data from these distant species, we limited our
review of non-human animal signals to primates. This decision was motivated by a higher prob-
ability of nding symplesiomorphies within the primate order, from which phenotypes with a simi-
lar function may have evolved through convergent evolution (Blount et al., 2018). Based on our
anecdotal knowledge before collecting data for the model, we expected to nd cooperative signals
in non-human primates that would result from analogical evolutionary processes as in humans. Yet,
we failed to nd comparably complex signals and comparable selective pressures for such signals
and, therefore, used the label rudimentarywhen describing non-human primate signals.
In this respect, both Alcorta and Kalan provide valuable examples of chimpanzee signals
that would modify our model if they could show that these signals originated under selective
pressures for cooperation among non-kin. Our reading of Wilson et al. (2007), cited by
Alcorta, is in line with what we argued in the target article when discussing pant-hoot chor-
using. Chimpanzee chorals are a collection of individual pant-hoots that most often occur
during the climax phase of the hoot (Soldati et al., 2022). This is important because the climax
phase encodes signaler identity and social status (Fedurek et al., 2016) and, therefore, does not
operate through increasing the perception of mutual relatedness, as we argued for similarity
signals. However, after reconsideration, pant-hoot chorusing might be better placed in the coa-
litional signals section because chorusing is correlated with short-term aliative behavioral pat-
terns and may thus serve to express shared interests (Fedurek et al., 2013).
chorusing would not signal participation in a specic collective action, since chimpanzees likely
lack the ability to share a goal (Tomasello et al., 2012), leaving chorusing as a rudimentary
coalitional signal.
The example of reassurance gestures performed by chimpanzees before and during border
patrols described in Watts et al. (2006) and cited by Kalan also directly relates to our
model. Given that chimpanzees are sensitive to the imbalance of power (Wilson et al., 2001),
using reassurance gestures to prevent shirking during border patrols may facilitate a sucient
number of patrol members who are more likely to succeed in an aggressive incursion into
another groups territory. While we described reassurance gestures as commitment signals in
our main paper, we failed to nd an instance of reassurance gestures occurring in contexts
where group cooperation would be essential. Watts et al.s observation is, therefore, exciting
in this context.
Chimpanzee reassurance gestures may further stimulate the debate on whether reassurance ges-
tures appearing in cooperative contexts are a case of convergent evolution between chimpanzees
and humans or whether these signals may be ancestral in hominids. Similar to chimpanzee reassur-
ance gestures, early hominin commitment signals were likely limited to current rather than future
cooperative contexts, costs were associated with vulnerability rather than with the production of the
signal, and the signals were dyadic. If supported, this convergence would strengthen our argument
about the importance of selective pressures on cooperation among non-kin and the likely adaptive
responses to such pressures (i.e., ritualized signals). Nevertheless, we maintain that further evol-
ution of commitment signals in H. Sapiens would require a dierent neuro-cognitive machinery
than re-assurance gestures, qualitatively separating these signals. In contrast to the early reassur-
ance gestures, currently observed human commitment signals refer to the distant future, the signals
involve direct production costs, and the signals are broadcasted to multiple receivers. Although
Kalan points out that taking part in border patrol is a one-to-many signal (we agree), it is not a
ritualized signal. Similarly, helping in coalitionary aggression is an index of support for this
coalition but not a ritual. For these reasons, we believe that reassurance gestures might be the
case of convergent evolution between early hominins and chimpanzees but are not a
To advance the understanding of the role that pant-hoot chorusing and reassurance gestures
may have played in the evolution of human collective ritual, we need to catalog the occurrence
of these behaviors in the primate order together with information on the context in which these
behaviors appear and the relationship between the signaler and receiver. Such data could be
used in a phylogenetic analysis of chorusing and reassurance gestures and shed light on the timing
of their origin. If we were to nd that these behaviors were ancestral in the hominid lineage, we
would need to redene human commitment and coalitional signals as well as the timing of their
origin (although this would not necessarily alter our estimation of the rst appearance of costly
commitment signals as we outlined them in the target article).
4. The evolution of collective ritual in hominins
4.1. Mechanisms
In the target article, we highlighted several mechanistic hierarchies that underlie the functioning of
human collective ritual. Alcorta again critiqued our approach to selecting these mechanisms for
relying on human exceptionalism, and Fischer suggested that we might have missed important
mechanisms necessary for the assumed evolution of the three ritualized signals. We are grateful
for these comments and oer our replies in the same order.
Similar to our discussion of non-human animal signals above, the neuro-cognitive mechanisms
we identied as essential for establishing ritualized signals are not exclusively found in humans. In
this respect, we concur with Alcorta that human cognition is an instance of primate cognition and
is not necessarily unique. Our target article was designed precisely with this notion in mind. We
thought the dierences in neuro-cognitive mechanisms within the primate order were always of
a degreerather than of a kind.While this nuance might have been lost during various stages
of editing and shortening the target article, it is one of the leitmotifs of our model. Nevertheless,
species in the hominid family had dierent evolutionary pathways that resulted in dierent modi-
cations of various mechanisms as well as their composition (Bechtel, 2007; Lang, 2019). In other
words, although humans share many neuro-cognitive mechanisms with other primates, these
mechanisms were molded by dierent selective pressures and are, therefore, dierent to some
extent. The extent of this dierence is the issue that needs to be addressed.
For example, Alcorta points out that the transportation of tools observed in chimpanzees indi-
cates their ability of mental time travel. We agree, and, as we mention in the target article, similar
abilities (tool transport in the distance < 10 km) were likely characteristic of hominins associated
with the Oldowan industry (Plummer, 2004). However, while chimpanzees transport tools to dis-
tant foraging sites (Motes-Rodrigo et al., 2019), they rarely transport raw material, which would
indicate foreseeing the need to make tools at distant sites in the future (Carvalho et al., 2008). In
contrast, there is evidence for a long-distance (50 km) transport of raw materials for stone-tool
making associated with hominins by 300 kya (Brooks et al., 2018; Roebroeks & Vill, 2011).
This dierence is further supported by an experimental study showing that compared to four-
year-old children (but not to two-year-olds), chimpanzees lack the ability to prepare for both prob-
able yet mutually exclusive event outcomes (Suddendorf et al., 2017). Mental time travel abilities are
likely part of the chimpanzee cognitive architecture, as evidenced by goal-oriented toolmaking and
tool transportation (Pruetz & Bertolani, 2007), but to a lower degree than in humans.
A similar argument can be made about imitation or, more specically, about overimitation (or
high-delity imitation). We acknowledge that, again, our short description of the research on
human imitation might have given a wrong impression of human exceptionalism, as pointed out
by Alcorta. We are aware that the mirror-neuron system was rst identied in macaques (Gallese
et al., 1996) and that the same system can be found in chimpanzees (Hecht et al., 2013). Moreover,
the non-human primate mirror-neuron system may facilitate eects akin to what we labeled simi-
larity signals,although the evidence is somewhat preliminary. For example, non-human great apes
react to being imitated by a human experimenter (Haun & Call, 2008), and capuchin monkeys pre-
ferentially treat humans who mimicked them (Paukner et al., 2009). However, instances of mutual
mimicking relationships in non-human primates are rare. There is some evidence that a few indi-
vidual chimpanzees and macaques may be able to follow the nger taps of others (Nagasaka et al.,
2013; Yu & Tomonaga, 2015), but this evidence is substantially underpowered.
Per our notion of dierential mechanistic composition between humans and non-human pri-
mates, the human mirror-neuron activation comprises ventral premotor neurons, prefrontal cortex,
inferior parietal lobule, and supramarginal gyrus in addition to the primate systems (Gallese et al.,
2011). The specically human activation of the ventral prefrontal cortex in action observation
suggests that humans represent othersactions in a hierarchical manner (Hecht et al., 2013) and
monitor specic sub-actions (Kaneko & Tomonaga, 2012). The imitation of specic sub-actions
without relying solely on the end product of the action is what dierentiates between the non-
human great ape ability to emulate the action and human high-delity imitation of all the action
sub-steps (Renner, Patterson, & Subiaul, 2020; Tennie et al., 2009). The dierence in the degree
of imitation has important consequences for the dynamics of cultural innovations in these dierent
It was proposed that chimpanzees are capable of product copying,that is, understanding the
relationship between a tool and a desired outcome (Tennie et al., 2009). Chimpanzees observing nut
cracking will use stones as a hammer and anvil to produce the outcome. However, they will not
copy the precise movements leading to cracking a nut, that is to say, the know-how behind tool
production. Thus, each chimpanzee must reinvent the wheel(Tennie, 2023; Tennie et al.,
2020; but see Whiten, 2022). Humans, on the other hand, are much more focused on high-delity
process copying(Tennie et al., 2009), which can give rise to cumulative culture (Henrich, 2016;
Laland, 2017). While chimpanzees have a relatively rich toolkit compared to other primates (Kühl
et al., 2019), the toolkit does not exhibit the process of cumulative culture as observed in the homi-
nin lithic technology.
Likewise, although non-human primates do imitate, the high-delity human imitation is more
precise and, importantly, more general (Laland, 2017, p. 97), allowing for the exact mimicking of
othersmovements as well as social transmission of complex ritualized signals in dierent contexts.
It could be hypothesized that the increasing dependence on cumulative culture would pressure on
the hominin ability of high-delity imitation and social learning (Heyes & Catmur, 2020), further-
ing the dierence in imitative abilities between hominins and non-human primates (as pointed out
by Alcorta). Yet again, while the cognitive systems of non-human primates operate on the same
mechanisms as human systems (e.g., imitation), both are adapted to their particular socio-ecologies
and work to dierent degrees due to their gradual co-evolution with other mechanisms.
In this respect, Fischers question about when synchronous ritualized signals co-opted the func-
tion of mimicry might be answered by looking at this gradual mechanistic complexication. While
intentionally imitating another person is a crucial steppingstone to behavioral synchrony (such as
dancing in unison), engaging in dyadic and, by extension, collective synchronized performance
requires the ability to form a shared goal between two and more individuals (move together in
sync). That is, synchronous behavior presupposes recursion because mutual action understanding
is crucial for joint action. Recursion allows us to monitor each othersperformance and dynamically
adjust inter-individual coordination (Vesper et al., 2010). Moreover, moving in unison requires the
ability to imitate each other in a specic rhythmic pattern, which relies on the ability to perceive and
produce metric patterns and entrain movements to the metric pattern (Richter & Ostovar, 2016).
Common neural coding between the sensory-motor areas has been shown to facilitate both the pro-
duction and perception of auditory rhythms (Grahn & Brett, 2007), suggesting a tight coupling
between the perception of metric patterns and action. Indeed, it was shown that such coupling is
often automatic in humans, even if detrimental to the task at hand (Lang et al., 2016; Richardson
et al., 2007).
Using the timeline of the evolution of mechanisms facilitating ritualized signaling constructed in
the target article, we can surmise that following each other in a rhythmic pattern likely evolved
together with high-delity imitation (Laland et al., 2016) in early members of the Homo genus.
On the other hand, recursion and shared intentions would be characteristic at the earliest for
H. heidelbergensis after 500 kya. Although mimicry and imitation may be ancestrally old, we expect
collective synchrony to be much younger and widespread only after 300 kya (given the wider spread
of archaeological evidence for coordinated group action across Africa referenced in the target
The second question raised by Fischer regarding mimicry (and, we may add, similarity signals in
general) is its honesty. As he correctly notes, mimicry is often used in the non-human animal realm
to fake a phenotype (e.g., being poisonous) to deter predators at a relatively low cost. We agree that
the same would hold for the early similarity signals and, to some extent, coalitional signals. Only the
cost/benetdierential associated with commitment signals may make signals honest. Without the
capability to attach a production cost to cooperative signals (or otherwise disadvantage the low-
quality signalers; Számadó et al., 2022), hominins would need other mechanisms to stabilize simi-
larity signals. The most obvious candidates are direct and indirect reciprocity, given that we
assumed the prevalence of similarity signals in early hominins living in smaller groups than, for
example, early H. Sapiens. In this respect, similarity signals would serve as a low-cost reminder
of shared interests that could sway another individual into a mutually benecial cooperative action,
but reciprocity and genetic relatedness would be more prevalent mechanisms for H. ergaster.
4.2. Selective pressures
Some commentators questioned the selective pressures we identied as the main culprits shaping
hominin cooperative communication. We appreciate all their insights and nd them deeply infor-
mative. First, Stibbard-Hawkes cautions against associating cooperative hunting with collective
ritual based on anecdotal ethnographic evidence. We agree entirely. A much stronger cross-cultural
link needs to be established between the co-occurrence (and/or the intensity) of collective ritual and
the complexity (and/or the intensity) of the collective hunt. Only then will it make sense to answer
whether the need for collective hunting was, in fact, one of the crucial selective pressures. For this
purpose, in the target article, we already suggested the phylogenetic analysis to weigh the relative
importance of various selective pressures.
Another counterpoint Stibbard-Hawkes oers is that among many hunter-gatherer groups,
hunting is not extensively collaborative and often even solitary (using the Hadza hunting as an
example). While agreeing that collective hunting is not universally present among hunter-gatherers,
we would like to point out the amount of historical, ethnographic, and archeological evidence of not
only communal hunting but of large-scale communal hunting (where hundreds of individuals reg-
ularly cooperated) across North America, Southwest Asia, Africa, South America, and Australia
(Boyd & Richerson, 2022). Thus, we are not convinced that the Hadza example, or several other
cases in point, should tip the scale against the extended scope of communal hunting in hunter-gath-
erers. Furthermore, Stibbard-Hawkes argues that the Hadza hunting expeditions comprise only
four peopleon average, illustrating how small some hunting parties may be. Nevertheless, our
model assumes that the early ritualized signals evolved at the dyadic level and only slowly scaled
up to triads and then further on. Therefore, a four-person hunting party would be sucient selec-
tive pressure for the evolution of ritualized communication since this party requires both coalition-
ary recruitment and commitment to the shared goal.
We also agree that it could be misleading to use present-day or historically recent hunting prac-
tices of hunters-gatherers and project them uncritically onto the models of the deep past, as Stib-
bard-Hawkes notes. Yet, it is the Pleistocene cooperative hunting we are interested in, and we
cannot avoid a certain amount of critically reected projections from contemporary practices to
the past if we are to estimate the evolution of ritual. For example, the evidence of repeated in
situ processing of complete carcasses of fallow deer (Gesher Benot Yaaqov, Israel; Rabinovich
et al., 2008) may suggest that hominins were regularly killing large game by 780 ka, or at least
defending large carcasses.
Large-game hunting (horse) consistent with hand-held wooden spears
perforations appears as early as 500 ka (Boxgrove, West Sussex; Roberts & Partt, 1999) and
throwing wooden spears as early as 400 ka (Schöningen, Germany; Thieme, 1997). Around the
same time, we also see the earliest appearance of stone-tipped hunting equipment in the African
archeological record (Kathu Pan, South Africa; Wilkins et al., 2012). We acknowledge that these
instances are only indirect lines of evidence for communal hunting assuming that the discovered
tools were used to nish otrapped or exhausted animals resulting from the use of driving tech-
niques (i.e., the combination of drivers, various articial driveline structures such as stone fences
or cairns, and naturally occurring elements such as pits, clis, trenches, bogs, or rivers).
Nevertheless, there are clear examples starting at 400 ka of mass bison killings requiring the coor-
dinated eort of a large number of people (Boyd and Richerson estimate 25 hunters; Gran Dolina
Atapuerca, Spain; Rodríguez-Hidalgo et al., 2017).
There is also some evidence pointing to large-
scale collective hunting events in the African record though it is considerably younger (Middle
Stone Age) and less conclusive (Jenkins et al., 2017). To sum up, with these examples, we would
like to fully endorse the point Stibbard-Hawkes himself hints at in his commentary that until
the invention and spread of composite projectile technologies (e.g., javelin or bow-and-arrow),
hunting with thrusting spears was more cooperative by necessity.
Another objection to the selective pressure of cooperative hunting raised by Stibbard-Hawkes
pertains to the riskiness of collective hunting. We acknowledge that the spectrum of risk involved
in collective hunts depends on many factors, such as weather conditions, the type of driving tech-
nique, and the type of prey. However, this spectrum almost certainly included high-risk confronta-
tions with dangerous prey species. Recent archeozoological evidence from 125 ka (Neumark-
Nord site complex, Germany; Gaudzinsky-Windheuser et al., 2023) shows that Neanderthals
hunted straight-tusked elephants (the largest terrestrial mammals of the Pleistocene weighing up
to 13 metric tons, i.e., twice the size of living African elephants) for over two thousand years. Simi-
larly, comparing isotopic dierences between Neanderthals and hyaenas shows that Neanderthals
ate much higher amounts of woolly rhinoceros and woolly mammoth while eating similar amounts
of large deer and horse, suggesting that Neanderthals did not acquire this prey through scavenging
(Saint-Césaire, France; Bocherens et al., 2005). Apart from the very large herbivores, there is also
evidence of human predation of both cave bears (roughly fty percent larger than modern-day griz-
zly bears) and brown bears (Rio Secco Cave and Fumane Cave, Italy; Romandini et al., 2018).
Stibbard-Hawkes and Glowacki both express another doubt, namely, whether humans truly
need ritual for collective hunting since hunts in many other species such as wild dogs and dolphins
(Glowacki) or lions (Stibbard-Hawkes) arguably lack such ritualized communication. Similar to the
previously discussed examples of cooperative signals and mechanisms in the mutually distant
species, we would like to caution against broad cross-species comparisons. While overlapping gen-
etic interests might facilitate some cooperative hunting, some actions may appear cooperative at
rst sight but might not be instances of mutualistic cooperation. In both cases, we would not be
addressing the key selective pressure we set out to address, i.e., the pressure for increasing risky
cooperative action among non-related individuals.
When capturing a single large prey, the close kinship of hunting partners allows them to hunt a
wider variety of prey and to cooperate at a larger group size (Packer & Ruttan, 1988). It is note-
worthy that male lion-hunting coalitions are always composed of kin whenever they should
reach the size of four individuals or more, while smaller coalitions are commonly composed of
non-kin (Packer & Pusey, 1982; Pusey & Packer, 1987). Our intention here is not to claim that
all evolution of cooperative hunting across all species can be explained by kinship or ritual. We
would only like to stress that the further away we venture from our lineage in the cross-species com-
parisons, the more factors we need to consider. For example, sociality in spiders is rare (only 2030
species are considered social; Avilés, 1997), and behind their unusual cooperativeness (e.g., remain-
ing with the same colony even when the prey availability is low) are high levels of inbreeding and
relatedness among colony members (Johannesen et al., 2002). Most informative would thus, again,
be the cooperative hunting in our closest living relatives.
Some authors argued that chimpanzees engage in collective hunts where individuals take the
roles of chasers, blockers, or drivers (Boesch, 2002) and assumed that cooperators also share the
spoils of their hunt (Boesch, 1994). However, further evidence cast doubt on the suggestion that
these hunts constitute mutualistic cooperation (Gilby et al., 2015). The proponents of the impact
hunter hypothesis argue that prey is not divided according to participation in the hunt but rather
enforced by harassment (Gilby, 2006) and that attending the hunt is dependent on the proximity to
the individuals who initiate the hunt and build excitation. However, even though these group hunts
increase the chance of successful hunting due to the large number of hunters, these hunts lack
shared goal, cooperation in goal attainment, and co-representing roles of other actors. That is, it is
not cooperative hunting. Furthermore, with most of the prey under 10 kg, chimpanzee hunts are
not risky compared to hunter-gatherer large-game hunting (Wood & Gilby, 2017).
Lastly, Stibbard-Hawkes questions the prevalence and intensity of coordinated Paleolithic vio-
lence, where he reaches a conclusion that conict was plausibly important, yet he sees the debate as
contested and unresolved. Indeed, the jury is still out on the evolutionary signicance of warfare
(i.e., whether this pressure was stable, substantial, and long enough during human evolution). How-
ever, convergent lines of evidence convince us about the strength of Paleolithic inter-group conict.
Warfare, collective raiding (e.g., stealth ambushes with superior numbers) and defense, and other
forms of violent group confrontations (e.g., pitched battles between tribes), are strong theoretical
adepts for the collective action problem, especially when the immense individual costs bring
benets to the ever-increasing number of genetically unrelated individuals (Zeerman & Mathew,
2015). Such benets of outcompeting other groups ultimately involve driving others to harsher
environments, assimilation, or elimination, a process observed in both chimpanzees and human
hunter-gatherer populations (Henrich, 2016, p. 171).
Recent studies of warfare within small-scale societies start to back the theoretical assumptions
with empirical evidence. While preindustrial agricultural societies engage in violent intergroup
conict much more than hunter-gatherers, as do horticultural societies (Hames, 2019), warfare
in hunter-gatherers is substantial, with 70% to 90% of hunter-gatherer societies experiencing war
every year or at least once every ve years. With 15% mortality rate estimates, the frequency and
intensity of hunter-gatherer warfare are greater compared to large-scale sedentary societies
(Bowles, 2006; Choi & Bowles, 2007; Ember, 1978; Gat, 2006,2015; Keeley, 1997; Reich, 2018;
for a review of evidence that nomadic hunter-gatherers may have waged large-scale battles see
Boyd, 2018, p. 74).
While the warfare frequency of contemporary and recent hunter-gatherer groups supports our
argument, we also need to reconstruct these rates in the Pleistocene foraging societies (LeBlanc,
2014) by comparing chimpanzees (Muller et al., 2017) and available archaeological records for
small-scale human societies. Whereas the former has a 4% to 13% mortality rate (Mitani et al.,
2010; Wilson et al., 2014; Wrangham & Glowacki, 2012), the latter has a 13% mortality rate
(Allen & Jones, 2014; Lambert, 1997), suggesting that similar rates might have been typical for
the last common ancestor of humans and chimpanzees. Moreover, there is also new archeological
evidence for recurrent episodes of interpersonal violence in the Late Pleistocene based on skeletons
exhibiting both healed and unhealed trauma (Crevecoeur et al., 2021). Importantly for our argu-
ment, large-scale warfare also likely occurred between dierent ethnolinguistic groups, who needed
to recruit combatants from several tribes. In this scenario, social technologies such as collective
rituals that facilitate trust between individuals from dierent tribes are paramount to the successful
recruitment and commitment of combatants (for other social technologies increasing the trust-
worthiness of parochial warriors in cultural species, see Řezníček & Kundt, 2020).
5. Alternative explanations
Several commentators suggested that rituals may have dierent functions based on the eects
observed in contemporary populations. We discuss these alternative propositions below, but before
doing so, we need to clarify our understanding of the distinction between a trait being an adaptation
and a trait being adaptive (Sosis, 2009). This distinction is best understood through the aforemen-
tioned lens of Tinbergens(1963) levels of analysis. The former is a question about the past environ-
mental adaptive challenges, if they were stable and substantial enough for any selection to shape a
trait/strategy as an eective solution in response to them, what type of selection was it, and what
were the functions the trait was to provide (in other words, adaptations have an evolutionary history
of selection). The latter is a question about the tness outcomes of a current, reasonably widespread
behavioral variant when compared with other behavioral alternatives (Symons, 1990). This
distinction is important because as the adaptations might or might not be adaptive in the current
environment (they might have remained adaptivethe so-called current adaptations, or become
maladaptive due to the discrepancy between the past and current environmentsthe so-called
past adaptations), so the adaptive behaviors might or might not originated as adaptations (they
might be the current adaptations or the so-called exaptationstraits whose role that currently
increments reproductive success was not built by natural selection, although natural selection
may later shape it). The adaptivist program (as opposed to the adaptationist program the histori-
cal explanation of the origin) is of no less importance or consequence; it just searches for answers to
dierent questions (Endler, 1986; Turke, 1990). As our quest is the search for the origin of human
collective ritual, we cannot allow ourselves to be sidetracked by the current adaptive function of
ritual. When some of the remarks of our commentators seem to transgress too much into the adap-
tivist program (e.g., FischersMy commentary will focus on two issues that need further attention:
a) to what extent rituals are adaptive …”), we either do not answer those comments or rephrase
them into the relevant form for our adaptationist quest.
5.1. Rituals evolved to facilitate social cohesion
Alcorta and Glowacki noted that ritual is not only a communication device but also a potent social
technology that has important eects on performers. Specically, they argued that ritual generates
within-group bonds (or fusion) rather than signals these bonds. Although we discussed this possi-
bility in the target article, we welcome the opportunity to elaborate.
First, as noted at the beginning of this section, we need to be careful with identifying the ultimate
and proximate causes of behavior, dierentiating between traits that are adaptations and traits that
are adaptive. In other words, traits that have a function and traits that have an eect (Williams,
1966). We do not doubt that collective ritual has social bonding eects, and we stated as much
in the target article and in our previous empirical work on this topic (Lang, 2019; Lang et al.,
2017). Yet, we argue that the social bonding eect is not the ultimate function of ritual, that is,
why ritual behavior might have been selected for. In the evolutionary timeline, social bonding
eects (although independently existing earlier) would be a later addition to the already established
ritualized signals.
To support her thesis, Alcorta cites research showing that dominance and submission rituals
aect various neuro-hormonal systems. Despite these persuasive ndings, any eects of submission
rituals need to be secondary to the communicative gesture because it is dicult to imagine an indi-
vidual voluntarily performing a submission gesture to become more submissive. As a matter of fact,
previous experiments conducted in our laboratory showed that submissive ritual postures do not
have any reliable and consistent eects on perceived submissiveness (Kundtová Klocová, 2018).
These results are in line with the broader critique of the embodiment paradigm, failing to support
claims that postures (e.g., power posing) and gestures (e.g., fake smile) induct these states in per-
formers (Ranehill et al., 2015). Rather, submission comes rst and is communicated through the
ritualized gesture, which can then strengthen the perceived submissiveness.
Likewise for the bonding eects of ritual, it has been long held in psychology that forced
initiation rites cause people like the group they were initiated into (Aronson & Mills, 1959). In
their pioneering research, Aronson and Mills showed that women who had to read aloud sex-
related swear words to join a group valued this group more than women undergoing mild initiation.
Although similar eects were observed in later studies (Gerard & Mathewson, 1966; Keating et al.,
2005), other researchers failed to replicate these results with high-powered laboratory studies on the
general population (Lang et al., 2023; Lodewijkx & Syroit, 1997) as well as with long-term studies of
university hazing rituals (Cimino & Thomas, 2022).
Thus, per our citation of Rappaport (1999) in the target article, we conjecture that rituals have a
critical auto-communicative function that amplies the signaled qualities but cannot create them ex
nihilo. Using the example of the pre-raid ritual provided by Glowacki, these rituals may fuse raiders
together, but they would not work if none of the participants planned to partake in the raid. For
instance, in 1988, most Hupa tribal activists refused to perform the Jump Dance with the Yuroks
due to territorial disputes (Buckley, 2000, p. 48). Not participating sent an essential message
about the state of the Hupa activists, and no dancing could have changed that state if they were
unwilling to perform it.
A similar case can be made about the presence of music and dance in rituals. These social tech-
nologies may indeed aect social bonding (Tarr et al., 2014) and fortify the communicative aspect of
ritual (on top of the autosignalling mentioned above). However, as we explained in the target article,
it is unclear why those practices need to be ritualized. If music and dance are groomingpractices
scaled up to hominin societies (Dunbar, 1998), it follows that they do not need to be ritualized to
reach their eects. Indeed, people might engage in play that does not need to be collective, repeti-
tive, and rigid to reinforce their social bonds, as we observe in other non-human primates (Shimada
& Sueur, 2018). The fact that music and dance are sometimes ritualized in the context of collective
rituals follows from their addition to the communicative function of ritual, which needs formaliza-
tion as a facilitating mechanism (see also Lang, 2023 for further arguments).
Finally, we also recognize that collective ritual may have additional eects on social bonding
because it is a form of collective action with a shared goal. For example, ritual performance may
generate the feeling of successful joint action (Reddish et al., 2013), which further promotes liking
among performers (Lang et al., 2017). While it is currently debated whether these eects are limited
to the performers or can extend to the general community (Chvaja et al., 2020; Reddish et al., 2014,
2016), it is true that ritual usually does not fail and perceived success of collective action may boost
social bonds similar to, for example, a successful hunt. Likewise, knowing that other ritual signalers
are willing to cooperate with the performer may automatically increase their liking and positive
aliation. Nevertheless, these eects are always secondary to the communicative function or
their by-product.
5.2. Rituals evolved to facilitate pair bonding
Alcorta defended another alternative explanation for the evolution of ritual, suggesting that analo-
gically to non-human animals, human ritual behavior has evolved to reliably communicate quality,
coalition, and commitment for pair-bonding partners.We agree that this is an essential alternative
since ritualized displays are often found in nature in the context of mate choice, and this selective
pressure is a reasonable prior for any speculation about the ultimate function of rituals. However, to
properly consider this alternative, we rst need to dene pair-boding, the timing of its evolution in
the hominin lineage, and the quality that is being signaled.
A pair bond is a psychological construct between two sexually mature individuals manifesting in
reciprocally transactional behaviors and expressions of mutual aection and that lasts beyond one
reproductive cycle (Bales et al., 2021). The pair bond is frequently equated with social monogamy,
most notably in birds, where 90% of the species are estimated to practice social monogamy. In
mammals, on the other hand, this number is estimated at 3%, although it increases to 15% when
we focus only on primates (Fuentes, 2000). Importantly, pair bonds are absent in our closest living
ancestors in the hominid lineage (Mitani et al., 2012), suggesting that this selective pressure did not
necessarily aect ritual displays in chimpanzees.
Focusing on the content of the signal, Alcorta pointed out that ritualized courtship displays sig-
nal quality (we assume genetic quality), coalition, and commitment. However, this suggestion mixes
two dierent signals that often vary along the polygyny/monogamy axis, namely selection of mates
due to their genetic quality that would be directly passed to ospring or due to their commitment to
the pair-bonded relationship (i.e., eliminating cuckoldry, increasing paternal investment, etc.), food
provisioning skills, territory size, and similar aspects aecting the signal receiver directly (Mitoyen
et al., 2019). These signals are often associated with dierent forms of signaling: while the former
involves exaggerated displays and vocalizations before copulation (mostly in polygynous birds;
Moller & Pomiankowski, 1993), the latter often involves inter-individual coordinated behaviors
where both partners take part in the performance (mostly in monogamous birds and some mon-
ogamous primates; Roth et al., 2021). Acknowledging the caveat of cross-species comparisons with-
out proper phylogenetic analysis as explained above, if we were to extrapolate these observations on
the evolution of human ritual, the former would be akin to a costly ritual performance where a
single individual aims to attract mates by signaling genetic quality while the latter to a dyadic coor-
dinated performance where two individuals mutually test and conrm their bond.
The former hypothesis was preliminarily refuted by Sosis et al. (2007), who found no association
between the cost of ritualized displays potentially indicating genetic quality and mating opportu-
nities assumed in increasingly polygynous societies. In a sample of 60 societies from the Probability
Sample File, Sosis and colleagues found that ritual costs were associated with warfare, suggesting
that selective pressures related to inter-group dynamics might potentially be more important in
forming human rituals than pressures on displaying individual genetic quality. Similarly, Xygalatas
and colleagues (2022) asked young unmarried women in Mauritius to rate potential short-term and
long-term partners while manipulating the intensity of ritual signals these potential partners dis-
played. They found that while ritual performance increased the chances of being selected, there
was no eect of ritual intensity. That is, men sending high-intensity ritual signals that may indicate
certain aspects of genetic quality had a similar chance to be selected as men performing non-intense
rituals, suggesting that women paid attention to the religious cues indicating basic coordination on
normative expectations of their potential partners rather than to their genetic quality possibly
associated with endurance.
This is not to say that there are no rituals where displaying genetic quality for the purpose of
mate choice would be the main theme. Certainly, there are. But we hazard that such rituals are
in the minority compared to group rituals occurring during the liturgical cycles of dierent
societies. This is an empirical question worth further pursuing in the review of ethnographic litera-
ture we suggested elsewhere in this response. Finally, we noted in the target article that rituals are
pluripotent, and the same ritual performance has dierent receivers that may extract dierent qual-
ities from the same signal. As with the ritual intensity study by Xygalatas and colleagues (2022),
some people may read intense ritual performance (e.g., ecstatic dancing) as a signal of commitment
to god while others as a signal of physical endurance. Nevertheless, the pluripotency of rituals cir-
cumvents the question about the ultimate function of ritual, which we argue was not associated with
signaling individual genetic qualities in male competition over females.
The hypothesis that ritual evolved as a signal of mutual commitment in pair-bonded individuals
is much closer to our proposal and a strong candidate for an alternative scenario, although only for
the evolution of similarity signals. Indeed, socially monogamous species engage in duetting displays
(including some primates) and other coordinated behavior, often over months before copulation
(Wachtmeister, 2001). Assuming convergent evolution between these dierent species and the
hominin lineage (given that pair bonding is absent in other hominids), it could be speculated
that the shift from promiscuity to pair bonding in the hominin lineage was the main selective
pressure on the evolution of similarity signals. However, given that pair bonds are not observed
in chimpanzees, we should expect dierent ritualized signals between chimpanzees and hominins
if pair bonding was the main selective pressure on ritualized signals. As we showed in the target
article and this response, there are some important similarities between the signals of these species
(albeit of dierent complexity). This caveat is further exacerbated by potentially dierent mechan-
isms facilitating duetting in non-human primates and similarity signals in humans. Whereas the
latter assume overimitation of each othersmovements, the former is about coordinated individual
production (i.e., there is no attempt to imitate the exact tone and pitch of another individual). For
this reason, even if duetting would exist before similarity signals in hominins, we would not necess-
arily consider it to be a ritualized signal.
Even if we would ignore this phylogenetic and mechanistic inconsistency, our model would not
need to change substantially to incorporate pair bonding as a selective pressure. What would need
to change in the model is the assumed selective pressure (from increased group size to pair bond-
ing). However, there is currently almost no evidence that could be used to test the co-occurrence of
pair-bonding with the presence of cognitive mechanisms underlying similarity signals. Despite hav-
ing several mathematical and verbal models of the evolution of human pair bonding (Chapais, 2013;
Gavrilets, 2012; Loo et al., 2017; Shultz et al., 2011), these models usually do not specify when the
evolutionary sequences occurred. There are several estimates based on sexual dimorphism (where
increasing dimorphism is a proxy for increasing male competition over females in polygynous
societies), but these estimates are highly variableranging from australopithecines to early
Homo (Schacht & Kramer, 2019)and preclude us from deciding which selective pressure was
more probable.
5.3. Rituals evolved to manage hazards and anxiety
Lightner, and briey also Glowacki, suggested that ritual may have evolved to manage hazards and
decrease anxiety before risky events. Again, we are sympathetic to the existence of these eects
(Lang et al., 2015,2020,2022) and have observed during our eld research a frequent usage of
magico-religious rituals in various contexts. However, we maintain that manipulation of future
hazards is not the primary function of ritual (Lang & Chvaja, 2023). We oer several arguments
why the communicative function of ritual may be the most probable evolutionary scenario,
although the uncertainty of the archaeological record is, of course, amenable to various scenarios,
as Lightner insightfully pointed out.
The crucial question we rst need to answer is the mechanistic underpinning of the ritual eects
on hazard management. While Lightner sketched a persuasive argument for these ritual eects, his
argument seems to presuppose magico-religious rituals tightly connected to belief in supernatural
agents (as per his argument about the adaptive eects of belief; Lightner & Hagen, 2022). That is,
supernatural agents (or forces) that could be manipulated to aect the future outcomes of hazar-
dous events or cure current maladies. However, as we argued in the target article, the neuro-cog-
nitive mechanisms facilitating belief in supernatural agents are much younger than mechanisms
needed for ritualized communication. Moreover, ritualized communication (commitment signals
in particular) would be needed for a group to coordinate on a costly belief in such agents (Lang,
2023), corroborating the evolutionary primacy of these signals.
A potential answer to this critique might point out that magical rituals do not need to presuppose
belief in supernatural agents, as they are formed through spurious associations (Fessler, 2006) or, in
other words, mistaking correlation for causation (Hong, 2022). For instance, wearing the same
socks during a winning streak in sports or relying on personal lucky charms to grant success
may be perceived as manipulating future outcomes (Gmelch, 1971; Rudski & Edwards, 2007).
Nevertheless, using a lucky charm to aect the future highlights the fact that these practices do
not necessarily need to be ritualized. A similar argument as in the case of social bonding eects
can be made heremagical practices do not explain the widely observed ritualization in H. Sapiens.
Having said that, we acknowledge that some magico-religious practices are ritualized. Following
the motif of spurious associations, it could be speculated that perceptual biases related to action
ecacy (Legare & Souza, 2012) would mold some manipulative actions with opaque causal chains
into repetitive and rigid action sequences that increase perceived ecacy. Repetitiveness and rigid-
ity would also ease the transmission of this practice through high-delity imitation, especially if the
cost of the practice is low and the perceived benets are high (Abbott & Sherratt, 2011). One unin-
tended consequence of such action ritualization could have been increased predictability of these
action sequences (Lang et al., 2015). Using such predictable action sequences to manipulate uncer-
tain futures might decrease internal entropy, eectively reducing anxiety (Lang et al., 2022).
Although these magical practices would not necessarily causally aect the desired outcome, by
reducing anxiety, they could prompt people to engage in riskier and potentially more benecial
actions. However, whether these eects would be adaptive depends on the presence of a discrepancy
between perceived and actual risks (Lang & Chvaja, 2023). Since anxiety is a hypercautious smoke
detector(Nesse, 2001), it may prevent people from engaging in high-risk/high-yield activities.
Therefore, the ritual decrease of anxiety could be adaptive in some contexts by reducing excessive
anxiety, for instance, during pre-battle rituals, as suggested by Glowacki (for a formal specication
of these contexts, see Lang & Chvaja, 2023).
Despite this plausible evolutionary scenario, we surmise that these ritual eects would be adap-
tive, but not an adaptation since they are contingent on the relative safety of ancestral environments
and the assumed overactivation of the anxiety subsystem. It is also likely that these adaptive eects
were not directly selected for and originated as a by-product of the pattern-seeking mechanism
assessing causal relationships. Moreover, note that we had to carve out a very specic aspect of
rituals to arrive at this hypothetical evolutionary pathway, eectively leaving much of the ritual fea-
tures (and features of collective rituals in particular) unexplained.
As stated in the target article, we are sympathetic to Lightners proposition about the multiple
eects of rituals and acknowledge that collective ritual is currently an amalgamation of various
functional and non-functional features. The particular blend of features may dier according to
the specic historical pathways of given communities and their socio-ecologies (Lang & Kundt,
2020; Sosis, 2020). For example, we observed that the Sittarai Kavadi ritual performed in Mauritius
is very costly (signaling commitment), yet many participants take part in the ritual to ask the god
Muruga for healing their illnesses or to express their gratitude for doing so (Xygalatas et al., 2019).
Our model of collective ritual is general enough to subsume these additional eects while respecting
the primacy of the communicative function. Interestingly, these various ritual functions and eects
do not need to be additive but can also interact. For instance, by mutually informing each other
about their support in adverse times, the communicative function of rituals may also decrease
the anxiety of performers by guaranteeing social safety nets in adverse times. In agreement with
this hypothesis, we observed that participants in Sittarai Kavadi subsequently enjoyed much social
attention and support (Xygalatas et al., 2019).
To conclude the section on possible alternatives of the ritual evolutionary pathway, it should also
be mentioned that collective ritual may have multiple functions that independently originated
under dierent selective pressures (rather than having one function and multiple eects, as we
suggested). This proposition would be better positioned to explain why we observe ritual behavior
in so many dierent contexts and why rituals have so many dierent eects. While we are skeptical
that these multiple origins would lead to a phenomenon with clear, cross-culturally shared aspects
that we and others observed (Rappaport, 1999; Sosis, 2004), we appeal to future phylogenetic work
to untie this Gordian knot.
6. Future directions
Throughout our response, we suggested several paths for future research to further test and revise
our model. We summarize the most important propositions here and would like to encourage
researchers to engage with these propositions to enrich our knowledge about rituals.
We perceive that a detailed phylogenetic analysis of collective ritual relying on quantitative eth-
nographic data is currently most needed, and this need was also highlighted by several of the com-
mentators (Fischer, Glowacki, Stibbard-Hawkes). Our model crucially relies on an assumed
relationship between socio-ecological selective pressures on within-group cooperation and corre-
sponding ritualized communication of cooperative intentions. While we provided several ethno-
graphic examples, this relationship must be addressed systematically to rule out alternative
explanations. As a matter of fact, we applied several times for funding to conduct this work, but
our proposal was never funded. We are determined to persist.
Coding ritual aspects across various ethnolinguistic communities and comparing them with
socio-ecological pressures could reveal whether collective rituals are indeed driven by the presence
of cooperative dilemmas (Sosis et al., 2007) or by sexual selection as Alcorta and others suggested
(Šaa et al., 2022), or by hazard management as Lightner suggested. For example, discovering that
red ochre is used predominantly in coalitional signaling under selective pressures on within-group
cooperation would rule out that its main function is health-related (despite being used in this con-
text by some communities). Likewise, we could assess the role of cooperative signals in coalitional
hunting, as Stibbard-Hawkes suggested, or battles and raids, as Glowacki suggested.
Such work may also suggest several ritual types that vary based on the context in which they are
employed. For instance, in anxiogenic contexts, we may observe magico-religious manipulative
rituals, as Lightner suggested, or after the cessation of inter-group conict, we may observe recon-
ciliation rituals, as Glowacki suggested. The primacy of signaling in these various ritual types will
most likely vary along a continuum, in agreement with our noted amalgamation of various func-
tions and eects in contemporary rituals.
Ethnographic coding could also contribute to a better typology of costly signals. Specically, we
need to dierentiate between signals that have production costs (as the handicap principle would
have it), opportunity costs, vulnerability costs, or investment costs that allow for cheap production
of an honest signal (Aimone et al., 2013; Brusse, 2019; Penn & Számadó, 2019). Understanding how
these dierent costs related to the reliable communication of cooperative intentions would provide
an important nuance to our model and possibly modify our timing of the evolution of commitment
signals. Likewise, further experimental work is needed to isolate the eects of individual ritual fea-
tures as we dened them in the target article as well as their interaction (Chvaja et al., 2022) and
more deeply investigate how the same signal may be used to communicate dierent strategies to
dierent receivers.
The model is also in dire need of more developmental data, as Clegg et al. suggested. While we
place the origins of ritualized communication into dyad-specic gestural patterns, it is clear that at
some point in the hominin past, these dyad-specic gestures transformed into institutionalized one-
to-many communication. The standardization of the group-specic communication code would
increase signal clarity but also demand clear transmission of these group-specic communication
patterns. Experimental work identifying developmental windows for acquiring the three ritualized
signals might help us corroborate or revise the proposed neuro-cognitive mechanisms underlying
each signal. A complementary work should also investigate the development of receiver psychology
(Soler et al., 2014). Finally, longitudinal data might help us understand how socialization into a par-
ticular signaling system aects the perceived costs of signaling and the associated benet of staying
in the group or lack thereof (Lang, Chvaja, et al., 2022; Sosis, 2003).
In conclusion of this response, we would like to again thank the commentators for their engage-
ment with the target article. We hope that the target article, together with the comments and our
response, will incept a broader investigation of the evolution of ritual, which is currently understu-
died and undertheorized. Indeed, as noted by Stibbard-Hawkes, our model is still speculative
despite our best eort to synthesize available evidence from multiple elds and should be taken
as the rst step in this investigation rather than the last word.
1. Furthermore, chorusing directed at other chimpanzee groups also honestly signals group size, as suggested by
Wilson et al. (2007). This is an interesting instance of signaling that may have parallels in human song and
dance (Hagen & Bryant, 2003), although it is far from our model of within-group communication.
2. Note that in our response, we relaxed the self-imposed constrain from the target article to draw evidence only
from the African continent. While relaxing this constrain adds another level of speculation into our model
(i.e., we need to assume that traits inferred from the European archaeological record were also present in
Africa), it is necessary to relax this constrain in order to support our response to the raised critique with
some illustrations. Unfortunately, the African archaeological record is often too sparse to draw meaningful
conclusions about specic questions (e.g., how risky were paleolithic hunts). Although we rely on these ana-
logies in our reply and they must be taken with a grain of salt, wherever possible, we also tried to include the
African archaeological record.
3. For a review of several younger European sites (Middle Palaeolitic, dating from 300 ka to 50 ka) where the
evidence for cooperative hunting of reindeer, bison, and horses is more robust, and estimates of the numbers
of hunters are even higher, see Gaudzinski-Windheuser & Kindler (2012).
4. For example, warfare among Turkana pastoralists living in northwest Kenya reaches a lethality of around 1 %,
and warring parties may involve up to several hundred warriors (Mathew & Boyd, 2014). As expected, many
combatants do free-ride by passive engagement or desertion.
5. Mindful of the whole spectrum of hunter-gatherer lifeways from egalitarian-nomadic to hierarchical-seden-
tary modes (Kelly, 2013) and cautious of the pitfalls of simplistic comparisons, dependency of political com-
plexity and societal stratication on newer technologies still compels us to deem mobile foragers to be the best
living models of Paleolithic foragers (Wilson & Glowacki, 2017).
Disclosure statement
No potential conict of interest was reported by the author(s).
This work was funded by the generous support from the Czech Science Foundation (GACR) [18-18316S].
Radek Kundt
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