Evolutionary Perspectives on Group Dynamics 1
Revision: December 2010

Social Minds:
Evolutionary Perspectives on Group Dynamics

Mark Van Vugt
VU University Amsterdam, the Netherlands

Tatsuya Kameda
Hokkaido University Sapporo, Japan[Invited chapter for Group Processes volume edited by John Levine]

WORD COUNT: 11,900

Evolutionary Perspectives on Group Dynamics 2
Abstract
Evolutionary psychology adds many insights to the literatures on group dynamics andsmall group processes. First, groups are a fundamental aspect of human evolution,suggesting that humans have evolved a range of adaptations to deal with specificthreats and opportunities afforded by living in groups. Second, an evolutionary
perspective integrates knowledge from numerous behavioural science disciplines suchas psychology, evolutionary biology, primatology, biological anthropology, social
neuroscience, and behavioural economics that are all concerned with group dynamics.
Third, an evolutionary analysis produces many novel hypotheses about different
aspects of our group psychology. We show the generativity of an evolutionary
psychological approach through discussing many examples of research applying
evolutionary thinking to understanding key adaptive group tasks such as coordination,social exchange, status, group cohesion, collective decision making, and intergrouprelations.

Evolutionary Perspectives on Group Dynamics 3
Social Minds:
Evolutionary Perspectives on Group Dynamics

Camp 10 Ms. Above the river Plate
Monday July 23rd , 1804.
“A fair morning-sent out a party of 5 men to look to timber for Ores two other parties
to hunt at 11 oClock Sent, G. Drewyer & Peter Crusett ½ Indn. to the Otteaus Village
about 18 ms. West of our Camp, to invite the Chiefs & principal men of that nation tocome & talk with us &. & also the panis if they Should meet with any of that nation(also on the S. Side of the Plate 30 ms. higher up). (at this season of the year all the
Indians in this quarter are in the Plains hunting the Buffalow from Some Signs Seenby our hunter and the Prairies being on fire in the derection of the Village induce a
belief that the Nation have returned to get green Corn)(By William Clark, Co-Captain of the Corps of Discovery [Nebraska editionof the Lewis & Clark journals edited by Gary E. Mouton]. All errors are original.)This quote comes from the journals of William Clark, who together with
Meriwether Lewis, led the expedition of the American West from 1804-1806. On theorders of President Jefferson, Lewis and Clark organized an expedition, travelling up
the Missouri River to the Rocky Mountains and westward along possible river routes
to the Pacific Ocean. The journal of their 3-year journey (along with a crew of 33
men) through unexplored territories in the US provides a vivid example of the many
challenges that human groups encounter in natural environments. This list includes
problems as diverse as securing food, finding safe shelters, acquiring knowledge
about places, animals and plants, protection against predators and hostile out-groups,

Evolutionary Perspectives on Group Dynamics 4
developing peaceful intergroup relationships, transmitting useful information,
following orders, and executing leadership and followership.
These are remarkably similar to the challenges that groups have faced
throughout human evolutionary history. Extrapolating from anthropological andarchaeological data, for at least several hundreds of thousands of years our humanancestors lived in small and closely tied groups -- much like the Lewis and Clark band
yet including men, women and children -- in natural environments. Although we canonly speculate about life in ancestral environments, there is little doubt that,throughout human evolution, groups have been key to the success of humans.
Applying evolutionary theory, group living can be viewed as an adaptive
strategy that increased the survival and reproductive success of ancestral humans.
This strategy was so successful that humans are among the most “groupish” animals
on the planet and together with the social insects have achieved ecological dominance(Wilson et al., 2008). Thus, students of group dynamics would be well served to takeseriously the role of human evolution in shaping our group psychology. Viewing
group processes through the lens of evolutionary theory also enables grouppsychologists to work together with biologists, anthropologists, economists,neuroscientists, sociologists, and other behavioural scientists in developing an
overarching theoretical framework on group dynamics..
Charles Darwin pioneered this new evolutionary science of groups. In his
second book, The Descent of Man, Darwin wrote: “With those animals which were
benefited by living in close association, the individuals which took the greatest
pleasure in society would best escape various dangers, while those that cared least for
their comrades, and lived solitary, would perish in greater numbers” (1871, p. 105).
Essentially, Darwin provided an evolutionary account for the affiliation motive which

Evolutionary Perspectives on Group Dynamics 5
is subsequently identified as one of the core human needs (Baumeister & Leary,1995).
For ancestral humans, evolving in hostile natural environments where dangers
were common and resources were scarce, group associations provided safety andcomfort. Only as group members could our ancestors acquire reproductively relevant
resources such as food and water and defend themselves against hostile animals andantagonistic out-groups. The conceptual implication is that humans have an innate
group psychology that regulates their group interactions. This yields a practical
implication as well. By applying the tools of evolutionary theory and psychology wehave the potential to more fully understand real-world group processes and improvethe design of teams and organizations.
Take the example of groupthink, the phenomenon that highly cohesive groups
under time pressures and directive leadership engage in poor decision-making (Janis,1972). From an evolutionary perspective, groupthink can be seen as the outcome of a
trade-off between two distinct strategies, getting the right information (accuracy) andkeeping group unity (cohesion). Under certain conditions, such as an imminent
external threat, it can be functional for all group members to form a united front andadhere to a group decision, regardless of whether the decision is factually correct.
This does not necessarily imply that it produces the best outcomes, especially incomplex modern environments. The ill-fated invasion of the Falkland Islands and theNASA Challenger disaster suggest that our evolved inclination to strive for group
unity may have dire consequences indeed.
In this chapter we first provide a brief introduction to evolutionary psychology
and its application to group processes. Second we discuss the diversity ofmethodological approaches that are used by evolutionary psychologists to find

Evolutionary Perspectives on Group Dynamics 6
evidence for group-level adaptations. Third we address the various functions ofgroups in human evolution and suggest that humans have evolved a host of
psychological mechanisms to solve critical challenges in six domains of group life: (a)coordination, (b) social exchange, (c) status, (d) group cohesion (e) collective
decision-making, and (f) intergroup relations. Finally we provide short and selective
reviews of the current state of knowledge in evolutionary research on each of these six
group challenges. We conclude by addressing some conceptual and practical
implications of a new evolutionary science of group dynamics.

Applying Evolutionary Thinking to Group Processes

An evolutionary approach to the study of groups starts with the recognition that thephysiological, neurological, and psychological processes involved in producing
human group behaviour are products of biological evolution. It follows, therefore, thatconceptual insights of evolutionary sciences can, when applied with rigor and care,produce novel discoveries about human group psychology (Caporael, 1997; Van Vugt
& Schaller, 2008). Indeed evolutionary inquiries have not only provided deeper
explanations for the origins of already-recognized psychological phenomena such as
mate preferences and fears and phobias, they also have produced an impressive arrayof novel theories, hypotheses, and empirical discoveries about the way humans
behave in groups and feel about them (Buss, 2005; Kameda & Tindale, 2006).
Evolutionary theory contains three simple premises based on the three coreDarwinian principles which together account for every aspect of living matter: (1)variation, (2) selection, and (3) retention. First, there is variation in traits amongindividuals – to illustrate with an example, some individuals are loners who prefer aEvolutionary Perspectives on Group Dynamics 7
solitary existence, whereas others are joiners who prefer to be in groups. Second,some of these trait variants enable their bearers to compete more successfully forreproductive resources – joiners can share resources and defend themselves better andas a result they have a better chance to produce off-spring (selection). Third, these
traits are heritable such that off-spring resemble parents – joiners (or loners) are more
likely to have children with joiner (or loner) genes (retention). Repeated over time,
this continuing process of variation, selection, and retention produces organisms andspecies that are well adapted to the environment in which they live: All modern
humans are the descendants of individuals who preferred group life over a solitary
existence.
An evolutionary psychology approach to group dynamics has the following
core assumptions:(a) Humans Have Social Brains. As a member of the family of primates,
humans have evolved as a group living species and therefore it is likely that many of
our cognitive adaptations are social psychological. For early humans, group life
formed a buffer against perturbations of the natural environment, so there must havebeen selection for traits facilitating group formation and group interaction. The social
brain hypothesis (Dunbar, 2001) posits that humans have evolved large brains in orderto make the most of living in large, complex social groupings. In support of the social
brain hypothesis, comparative studies have found a positive correlation between thesize of the pre-frontal cortex and average group size, comparing humans with otherprimates and comparing primates with other mammals. Humans come out on top,
having both a relatively large pre-frontal cortex and an associated large average groupsize. From the brain data, the extrapolated group size for humans is around 150
individuals -- also known as Dunbar’s number -- which corresponds roughly to theEvolutionary Perspectives on Group Dynamics 8
size of a small community like a neighbourhood or religious community that can beheld together through informal social control. One hundred and fifty is also themedian number of recipients on people’s Christmas card lists according to a UK study(Hill & Dunbar, 2003).
(b) Selection Forces Operate Together. Selection for groupish traits—traits
that enable individuals to enjoy and function well in groups such as sociability -- iscalled social selection, and this should be seen as a complementary selection force tonatural selection which reflects adaptations to the physical (natural) environment(Nesse, 2007). Sexual selection is a specific case of social selection, and some grouplevel traits may be the result of this selection force. Sexually selected traits evolve
because they increase the chances of an organism finding a sexual mate or being
chosen as a mate. For instance, some conspicuous group behaviours such as publicgenerosity or the display of humour have been interpreted as sexually selected traits
because these acts make individuals more attractive to the opposite sex (Griskevicius
et al, 2006; Iredale, van Vugt & Dunbar, 2006; Miller, 2001).
Most selection models assume that social traits have evolved because they
benefit the individual possessing that trait – for instance, empathy enables anindividual to assess other people’s intentions so that the person can protect himself or
herself against possible exploitation. Yet recent theorizing suggests that groupish
traits may also have been selected for because they produce benefits to the group towhich the individual belongs, thus producing an indirect pay-off to the individual(Caporael, 1997; Nowak, 2010; Wilson et al., 2008). Perhaps empathy evolved inhumans not so much to protect against cheaters but to build up cooperative groups
that do better than groups with less empathic members in competing for scarce

Evolutionary Perspectives on Group Dynamics 9
resources. Darwin was an early proponent of these group selection models and heused group selectionist thinking to account for the evolution of morality:“A tribe including many members who, from possessing [a high degree of] thespirit of patriotism, fidelity, obedience, courage and sympathy, were always ready toaid one another, and to sacrifice themselves for the common good, would be
victorious over most other tribes; and this would be natural selection” (p. 203).
After some fierce objection against group selection, evolutionary scientists are
increasingly considering it a useful framework for examining human group behaviour
although there is an ongoing debate about whether group selection operates on genes,
culture or perhaps a combination (Nowak, 2010; Richerson & Boyd, 2006; Wilson etal., 2008). Perhaps the lesson is that for each groupish trait one must look at both theindividual and group benefits associated with it, and in many cases there may be
multi-level selection forces operating in conjunction. For instance, having a sense of
humour may have the function to impress members of the opposite sex (a sexually
selected trait) but this trait may have evolved originally because of its function in
fostering group cohesion (Gervais & Wilson, 2005)(c) Evolved Psychological Mechanisms. Group-level adaptations come inmany different forms, and many contain physiological, neurological, psychological,
and behavioural elements. Adaptive group decision-making is activated by a set of
evolved psychological mechanisms that are instantiated in the brain. For instance,
human language is a biological adaptation enabling humans to transmit information
efficiently. Language requires the presence of both physical structures, such as
Broca’s area, and psychological mechanisms, such as a theory of mind, that enablehumans to communicate effectively. Thus, if humans can talk but chimpanzees (oneof our closest living relatives) cannot, it is because these two species differ in their

Evolutionary Perspectives on Group Dynamics 10
evolved physiology and psychology. (Language may be a group-level adaptation
which gave early human groups an edge in the competition for reproductively relevant
resources). Similarly, trust in strangers may be triggered by a psychologicalmechanism telling us to trust individuals who look familiar. This psychologicalmechanism might be activated by the secretion of a hormone such as oxytocin whichplays a role in forming emotional attachments (De Dreu et al., 2010). The key
message is that any group behaviour is regulated by both psychological (emotions,
cognitions and neuro-physiological (brain activity, hormones, and neurotransmitters)
mechanisms that evolved through natural selection.
(d) Automatic “If-Then” Decision Rules. Group-level adaptations can be
regarded as a set of heuristics or conditional (if-then) decision rules that are activatedin appropriate conditions. Because a social group is a complex environment it pays forhumans to have a broad repertoire of conditional decision rules to make adaptive
choices under a variety of conditions. For instance, a conditional decision rule such as“I will only cooperate if my partner cooperates but otherwise I will defect” enables anindividual to maximize his or her outcomes in social exchange situations (Axelrod,
1984). Many of these decision rules are likely to be highly automatic, meaning thatthey require little conscious deliberation to produce adaptive behaviours in a wide
range of situations.
(e) Domain Specificity of Mechanisms. Many groupish traits are likely to bedomain-specific decision rules. They exist in the form they do because they solved aparticular, recurrent group problem in our ancestral environment, such as
understanding how to defend the group or climb the group status hierarchy. The
primary aim of an evolutionary psychology approach to group dynamics is to identify,

Evolutionary Perspectives on Group Dynamics 11
analyze, and understand specific adaptive group problems as well as the psychologicalmechanisms that have evolved to solve them.
For instance, the phenomenon of social exclusion can be described in manydifferent ways —for instance, when it occurs and to whom and what are theconsequences for the victims? An evolutionary psychology approach would
additionally focus on the different functions of social exclusion in solving adaptive
group problems in ancestral environments. This “adaptationist” analysis suggests atleast three evolved functions of social exclusion: (1) excluding individuals who arelikely to be non-reciprocators; (2) excluding individuals who behave unpredictably,and (3) excluding individuals who constitute a contagion risk or coalitional threat(Kurzban & Leary, 2001). Each of these functions may have a unique underlying
psychology which is triggered by different stimuli and which produces different
behaviours that can solve the specific problem. For instance, people show aggression
towards a free-rider and behavioural avoidance to a person carrying a disease threat(Kerr & Levine, 2008; Schaller, Park & Mueller, 2003; Van Vugt & Park, 2009).
(f) Adaptations to Past Environments. A sixth assumption is that evolution
through natural selection is a painstakingly slow process spanning many generations.
The implication is that our evolved group psychology reflects adaptations to pastrather than present environments. Because modern humans live in very different
environments from their ancestors, some of our evolved psychological mechanisms
may not produce behaviours that are currently adaptive. For instance, most of theinteractions in ancestral human groups were probably with close kin, and so we may
not have evolved psychological machinery that is fine-tuned to interacting withgenetic strangers. An implication is that we are more likely to trust strangers if theyelicit kinship cues, such as facial resemblance, co-residence, or other “familiar” cues

Evolutionary Perspectives on Group Dynamics 12such as sharing the same surname (Park, Schaller & Van Vugt, 2008). Thus, it is truethat in modern organizations humans still carry around stone age brains.
(g) Asking Special Questions. An evolutionary approach to group processes
offers a meta-theoretical framework, guided by evolutionary theory, in which aparticular group behaviour must be understood at different levels of analysis. From
this perspective, it is important to ask four questions about a behaviour, correspondingto (1) its form, (2) its development within individuals, (3) its evolutionary history, and(4) its ultimate functions (Tinbergen, 1966). The first question concerns the proximate
causes of a group behaviour, for instance why do people conform to norm X but not
to norm Y? Many psychologists are mainly interested in this first level. The second
question concerns the developmental (ontogenetic) aspects of a behaviour such asconformity, for instance how do conformity rates vary across the life-time of people,
and why is it that adolescents are particularly likely to break societal norms? The third
question concerns the evolutionary (phylogenetic) history of a behaviour, for instancedo other species also have social norms and are these norms similar or different fromthose of humans? The answer to this question provides an indication of the origins ofa trait (Brosnan, Newton-Fisher & Van Vugt, 2009). The fourth question concerns theultimate functions of a behaviour, for instance what might have been the benefits ofnorm conformity for early humans? The third and fourth question most interest
evolutionary-minded group scientists. Ideally one should get answers to each of thesequestions to draw a complete picture of a particular group behaviour, and this often
requires adopting a multi-disciplinary perspective.
(h) Falsifying Evolutionary Theory. Finally, although the theoreticalframework we offer is guided by the principles of evolutionary theory, evolutionaryminded group researchers are not seeking to test evolutionary theory per se, because

Evolutionary Perspectives on Group Dynamics 13
evolution and natural selection are scientific facts. What they are testing are specificpredictions derived from hypotheses generated by middle-level evolutionary theories(Buss, 1995). For instance, the theory of indirect reciprocity suggests that individuals
cooperate in large groups because doing so benefits their reputations (Nowak &Sigmund, 2005). A hypothesis that follows is that when people’s actions are public
they will cooperate more. This produces the specific prediction that when people
know that they are being watched by another person they become more generous.
This prediction has received substantial support in both the laboratory and field(Bateson et al., 2006; Hardy & Van Vugt, 2006). Thus, while evolutionary theory
offers a framework that enables researchers to generate new hypotheses andpredictions, falsifying them does not cast doubt on the validity of evolutionary theory
per se.

Methodological Approaches to Studying Groups From an Evolutionary
Perspective

Evolutionary psychology represents an enormously diverse set of theories, methods,
and analytical perspectives (Gangestad & Simpson, 2007; Schaller, Simpson, &Kenrick, 2006; Scher & Rauscher, 2003). This conceptual and methodologicaldiversity results, in part, from the fact that evolutionary psychology attracts
contributions from scientists with an unusually diverse range of scholarly
backgrounds – not just scholars with different kinds of training within psychology,
but scholars from biology, primatology, zoology, anthropology, economics, andvarious other academic disciplines. In addition, this diversity is a functional responseto the high evidentiary standards that are applied to theories and hypotheses inEvolutionary Perspectives on Group Dynamics 14
evolutionary psychology (Conway & Schaller, 2002). Truly convincing support foran evolutionary hypothesis about some aspect of group psychology needs not only to
document the existence of the predicted psychological phenomenon, but also needs toprovide evidence for the alleged evolutionary origins of that phenomenon. The firstpart is relatively easy. The second part is hard.
It is exceedingly difficult to collect behavioural data in ancestral environments
or to empirically track the actual evolution of an alleged psychological adaptation.
Instead, evolutionary psychologists must rely on a multitude of other, more indirectsources of evidence to build a nomological network of findings and inter-relate thesefindings to offer support for an evolutionary hypothesis (Schmitt & Pilcher, 2004).
Evolutionary psychologists frequently begin with general theories – often
from the core principles of evolutionary biology – that guide their attention towardpotential psychological adaptations. Common theories used by evolutionary
psychologists include inclusive fitness theory, parental investment theory, life-history
theory, costly signalling theory, and evolutionary game theory. If a hypothesizedgroup adaptation flows directly from a general evolutionary theory, then evolutionary
psychologists feel a degree of confidence in the existence of a group-level adaptation.
For example, differences in parental investment lead to the hypotheses that men signal
their ability to acquire resources to women through public acts of generosity and thatwomen find generous men sexually more attractive (Iredale et al., 2008).
Evolutionary psychologists sometimes apply computer simulations to study
the evolution of group processes. In these simulations agents that reflect particularsocial strategies (such as a cooperative or defective strategy) interact with each otherand their fitness outcomes are examined to see if particular patterns emerge over time.
For instance, simulation studies show that stable levels of cooperation can evolve inEvolutionary Perspectives on Group Dynamics 15even large groups as long as agents can keep track of the past interactions of otheragents (image scoring; Nowak & Sigmund, 2005). Game theory models can be
helpful in identifying the conditions under which certain group traits evolve,
especially when they are competing with alternative traits. For instance, the Prisoner’s
Dilemma Game has been used to model the evolution of cooperation. This model
makes clear that mutual defection is the unique equilibrium in a one-shot play -which is the outcome most likely to emerge empirically. Only by making additional
assumptions, such as repeated play between the same actors, is there an opportunity
for the evolution of cooperation – for instance, through Tit-for-Tat (Axelrod, 1984).
Experimental methods of behavioural economics and social psychology arealso increasingly used to find evidence for social adaptations. These methods are used
to study interactions between players in games such as the prisoner’s dilemma game,the ultimatum game, the dictator game, and the public good game in which players
allocate resources. These methods have produced many interesting findings, forinstance by identifying the conditions under which players cooperate with each otherto defeat a common out-group (Van Vugt et al., 2007).
Methods from experimental cognitive psychology are also often used byevolutionary psychologists to find evidence for social adaptations. For instance,
relevant experiments have shown that men typically perform better than women on
spatial rotation tasks, whereas women typically perform better than men on spatial
memory tasks (Silverman & Eals, 1992). One evolutionary interpretation of this result
is that ancestral men – the primary hunters – evolved spatial capacities in order tonavigate through an unfamiliar terrain and track moving prey. In contrast, ancestral
women – the primary gatherers – evolved memory capacities in order to remember
fixed locations where fruits and nuts could be collected.

Evolutionary Perspectives on Group Dynamics 16
Psychological surveys can also provide evidence for social adaptations bycollecting self-report data about people’s experiences in real-world groups. For
instance, survey evidence reveals that the most important determinant of people’s
judgments about ideal group members is their trustworthiness, regardless of the typeof group or the nature of the group task (Cottrell, Neuberg & Li, 2007). This suggestthat humans have evolved decision rules to interact with people based upon how
much trust they elicit (Simpson, 2007).
Additional evidence for hypothesized group adaptations emerges from recent
advances in neuroscience. Brain imaging studies, for instance, have the potential toprovide data relevant to specific neural structures associated with group-relevant
cognition and behaviour (Adolphs 1999; Duchaine, Cosmides, & Tooby, 2001). For
instance, fMRI research has shown that when people experience social exclusion,
there is brain activity in a region that is also activated when people experience
physical pain, suggesting that these two kinds of “pain” share the same evolutionary
background (Eisenberger, Lieberman, & Williams, 2003). Moreover, hormonal
research can help identify the hormonal correlates of particular group-level
adaptations, such as the connection between status seeking and testosterone (Josephs
et al., 2006).
Behaviour genetics studies may be useful in clarifying whether a particularsocial adaptation has a substantial genetic component. Generally, when a trait has a
low heritability (the degree to which children resemble their parents on this trait) itmeans that the trait is relatively fixed in a population, which suggests a species typicalbiological adaptation. For instance, because every human is capable of acquiring it,
language is a species typical adaptation with low heritability. In contrast, a highheritability index suggests that there may be important individual differences in theseEvolutionary Perspectives on Group Dynamics 17
traits. This points to the possibility that there has been selection for different versionsof the trait in human evolution. For instance, introversion and extraversion are traits
with substantial heritable components which suggests that they may reflect different
evolutionary strategies – e.g., introversion may be functional in stable groups andextraversion in unstable groups (Nettle, 2006).
Anthropological and ethnographic databases can provide additional evidence
for an evolutionary hypothesis, testing the extent to which specific kinds of grouprelevant phenomena are universal across human cultures. This kind of evidence isnecessary to differentiate between phenomena that are evolutionary adaptations andthose that are more recent, culture-specific manifestations (Norenzayan, Schaller, &Heine, 2006). For instance, research on Western and Eastern cultures suggests that
whereas the tendency for positive self-regard is universal, the specific way it isexpressed differs across cultures (Sedikides et al, 2003).
Finally, cross-species evidence is instrumental in testing speculations about
the evolutionary history of an alleged social adaptation. Both chimpanzees andhumans, for instance, form coalitions to engage in intergroup violence – a finding
implying that the underlying psychological mechanisms predate the divergence ofchimpanzee and hominid lines from their immediate common ancestor (Brosnan et al.,2009).
When considered together, the findings from these diverse lines of inquiry
have produced important insights into the evolutionary bases of group processes.
Although no single finding tells a definitive story about the evolutionary significanceof any specific group behaviour, together they point to the existence of a number of
specialized mechanisms for dealing with the key challenges of group life.

Evolutionary Perspectives on Group Dynamics 18
Key Adaptive Problems of Group Life

What were the key adaptive challenges that early humans faced living in groups, andwhat mechanisms could have evolved to solve these? Based on the literature, we
identify six critical group challenges: (1) coordinating group activities (coordination);(2) exchanging resources (social exchange); (3) negotiating group hierarchies (status);(4) keeping groups together (group cohesion), (5) making collective decisions(collective decision-making), and (6) interacting with members of out-groups(intergroup relations). This list is neither exhaustive nor mutually exclusive yet it is agood starting point for building an adaptationist framework for analyzing groupprocesses. Furthermore, the list corresponds closely to the core themes of groupdynamics identified in textbooks such as Forsyth’s Group Dynamics (2010).
Each adaptive group challenge contains a subset of different problems that allneed to be solved to produce a good outcome. For example, coordinating a group
activity, such as moving the group from one location to another, requires identifying
an appropriate location to move to, deciding when to move and for how long,assessing which individuals possess the specific leadership expertise for the task,
motivating individuals to follow, keeping the group together while on the move,
replacing ineffective leaders, and setting up contingency plans (Van Vugt et al., 2008).
None of these adaptive group challenges have been fully analyzed using anevolutionary framework. Yet various research programs have contributed todeveloping such analyses by providing evidence for evolved psychologicalmechanisms that address a particular group challenge. The promise of an evolutionary
science of group dynamics lies in the generativity and productivity of this approach informulating novel hypotheses and providing supportive empirical evidence. To date

Evolutionary Perspectives on Group Dynamics 19
not many group-level adaptations have been explored fully in terms of their form,
function, phylogeny, and ontogeny. In the remainder of the chapter, we offer anillustrative set of findings of evolutionary inspired research programs for each of thesecore group challenges.

(1) Coordination
As a nomadic group living species early humans would have to solve
problems associated with coordinating their activities with other individuals insometimes very large groups. For instance, when moving they would have to decide
where to move to and when and for how long to stay there. It would have beenpotentially lethal for them to stay in one place for too long. To solve this would
involve specialized mechanisms for identifying situations as requiring coordination,
developing rules how to achieve coordination (e.g., turn-taking, leadership), andcarrying it out.
Leadership. One evolved mechanism that has recently been identified as
facilitating social coordination is leadership and followership. There are multiple
indications that leadership might be a social adaptation. Game-theory models showthat leadership – where one individual takes the initiative and others follow -- is a
powerful solution in such coordination games. Consider for instance, Pat and James,
who are thirsty and must find a water hole. They must stay together as a form ofprotection, but how do they decide which waterhole to go to? In such cases it isadaptive for one individual to take the initiative to go to a particular water hole, whichleaves the other no option but to follow. Coordinating on the same water hole is theequilibrium solution to this game, which suggests at least the possibility thatleadership and followership are evolved strategies (Van Vugt et al., 2008).

Evolutionary Perspectives on Group Dynamics 20
An implication is that leadership-followership interaction emerges
spontaneously and does not require much brain power to achieve. The emergence ofleadership has been documented across many different animal species that face
functionally important coordination problems, including teaching in ants, selecting
foraging sites in honey bees (the famous waggle dance), movement in stickleback
guppies, and peace-keeping in nonhuman primates (King et al., 2009). Among humanbeings, similar kinds of coordination problems also result in the emergence of leaderfollower relations. This occurs quickly and spontaneously across many different
situations and cultures, suggesting adaptation (Brown, 1991).
Of course, the exact leadership structure varies across situations and cultures,and there is evidence for both highly democratic and highly despotic leadership
structures in humans (Bass, 1990). They likely represent different adaptive solutions
to different local group conditions – for instance, dictatorial leadership might haveemerged initially in response to an immediate external crisis which required quick anddecisive action (Van Vugt, 2009).
There is ample evidence that leadership emergence is more likely amongindividuals with a predisposition to take initiatives, for example, because they haveextraverted, assertive, ambitious, energetic, or dominant personalities (Bass, 1990).
Because many such traits have a moderately strong heritable component, leadershipmay be a frequency dependent selected trait that has evolved to help individuals solve
coordination problems (Van Vugt, 2006).
The underlying evolutionary logic of leadership also yields hypotheses about
the psychological mechanisms underlying followership and leader emergence. An
evolutionary approach hypothesizes that humans possess specialized mechanisms for
identifying people who are most appropriate for solving a given adaptive problem

Evolutionary Perspectives on Group Dynamics 21
such as warfare or peacekeeping between groups. Recent studies suggest that warfare
elicits a masculine leader prototype, whereas peace elicits a feminine leader prototype(Little et al., 2007; Van Vugt & Spisak, 2008; cf. Lord et al., 1986).
Transactive memory. Another coordination device that may have evolved tosupport group coordination is a transactive memory system which enhances thecapacity of groups to store and quickly access information by dividing cognitive tasks
among group members. Cognitive cooperation is common in social insects and one
famous example is the waggle dance of the honey bee, a group decision making
device for selecting foraging sites (Seeley, 1995). Research on humans also suggeststhat members working in the same group often specialize in different areas and groupmembers are very quick at recognizing and using each other’s expertise (Littlepage etal., 2008). These individuals not only have more information on a given topic but they
are also the ones that are responsible for storing new information in their area ofexpertise. A set of experiments showed that teams performed better on a group task ifthey showed signs of task coordination and memory differentiation. Furthermore,teams with better transactive memory systems also trusted each other’s expertise more
(Moreland, Argote & Krishna, 1996). Not surprising, especially at more complex
cognitive tasks groups outperform individuals (Wilson et al., 2004).
Mimicry and behavioural synchrony. Another evolved mechanism for social
coordination is mimicry whereby individuals imitate each other in terms of theiractions, expressions, or postures. Mimicry is a highly automated process – it issometimes referred to as the chameleon effect (Chartrand & Bargh, 1990) – and its
main function is to smoothen coordination between interaction partners. Mimicry is
possible in humans because of the evolution of sophisticated cognitive capacities suchas theory of mind and empathy that likely emerged late in human evolution (aroundEvolutionary Perspectives on Group Dynamics 2250.000 years ago). Research suggests that mimicry and other forms of behaviouralsynchrony (such as making the same moves while dancing) increases people’s liking
for each other and their willingness to share: If people are being mimicked they
become more generous (Van Baaren et al., 2004). Finally, synchrony of emotions,both positive and negative, facilitates group performance (Klep, Wisse & Van derFlier, 2010).

(2) Social Exchange
Social exchange -- cooperation for mutual benefit -- is a pervasive and crossculturally universal feature of human group life. Exchanging vital resources withothers is fundamental for any gregarious species, yet humans are unique in being able
to establish large-scale cooperation with genetically-unrelated individuals.
Cheater detection. Evolutionary models suggest that for social exchanges with
non-kin members to persist stably, individuals must be able to detect “cheaters” who
do not reciprocate resources (Axerlod, 1984; Trivers, 1971). Cosmides (1989) argued
that humans have an evolved cognitive mechanism specialized for cheater detection.
A recent brain-imaging study with a patient who had bilateral limbic system damage
provided some evidence for this thesis. Using the Wason’s four-card selection task
paradigm, Stone, Cosmides, Tooby, Kroll and Knight (2002) showed that, compared
to normal controls, the patient’s performance was impaired only when the logicalreasoning task was framed as detecting violators of social-contracts. The performanceremained intact when the task was framed as detecting violators of non-contractualrules. This dissociation suggests that cheating (violations of social contracts) may beprocessed separately from other types of social violations by our brains.

Evolutionary Perspectives on Group Dynamics 23
Cooperation norms. Human collective action is often governed by a norm of“conditional cooperation” (Fehr & Fischbacher, 2004). This norm dictates that anindividual should cooperate if other group members cooperate, whereas he or she isallowed to not cooperate if the others defect. Fischbacher, Gächter, and Fehr (2001)
examined participant’s willingness to contribute in a one-shot public-goods
experiment as a function of the average contribution of the other group members.
Despite the economic incentives to free-ride (contribute nothing), 50% of theparticipants matched their contributions with the average contribution of othermembers. Furthermore, when participants simply observed the interaction of two
players in a Prisoner’s Dilemma game, they spent their own endowment to punish
players who defected unilaterally but not players who defected bilaterally (Fehr &Fischbacher, 2004). This pattern indicates that the norm of conditional cooperation(“unilateral defection is not acceptable”: Axelrod, 1984) is enforced by neutral
observers (“third parties”).
The evolutionary perspective suggests a novel hypothesis about thepsychological mechanisms underlying enforcement of cooperation norms. Given thatexchanges of valuable resources occur mainly within in-groups, violation ofcooperation norms should be more serious to one’s survival if committed by anotherin-group member than if committed by an out-group member. Then, non-cooperative
behaviour by in-group members should be punished more severely than noncooperative behaviour by out-group members. Using the third-party punishment
paradigm, Shinada, Yamagishi and Ohmura (2004) confirmed this prediction. Such a
selective sanctioning includes not only physical punishment but also social exclusion,collectively denying the violator’s access to interpersonal relations in a group. Recent
research reveals that interpersonal exclusion can provoke strong negative emotional

Evolutionary Perspectives on Group Dynamics 24
responses in the targeted individuals, including intense anger, pain and depression(Eisenberger et al., 2003). People are highly sensitive to interpersonal exclusion
because of its adaptive significance (Kerr & Levine, 2008; Van Vugt & Park, 2009).
Distribution norms. Distribution norms refer to a set of shared beliefs thatprescribes how resources should be distributed among group members. Evidence
suggests that motives for egalitarian sharing often operate strongly in resource
distribution (Fehr & Schmidt, 1999; Kameda, Takezawa, Ohtsubo & Hastie, 2010).
For example, results from numerous one-shot Ultimatum Game experiments indicatesthat modal offers by a proposer for a responder’s share are around 40-50% and thatoffers in this range are rarely rejected (Camerer, 2003). Although there are some
cultural differences, extremely small offers (1-10%) are rarely seen in the ultimatum
bargaining experiments conducted in a wide range of societies including primordial aswell as industrialized ones (Henrich, Boyd, Bowles, Gintis & Fehr, 2004).
Indeed, egalitarian sharing of hunted meat constitutes a core feature of huntergatherer life. Compared to collected resources (e.g., cassava), hunted meat is often thetarget of communal sharing. Kaplan and Hill (1985) argued that the sharing system
functions as a collective risk-reduction device. While acquisition of collectedresources is relatively stable and dependable, acquisition of meat is a highly variable,
uncertain event. By including many individuals in the sharing group, the variance inmeat supply decreases exponentially (Gurven, 2004). Kameda, Takezawa and Hastie(2003) conducted a series of evolutionary computer simulations to test the robustnessof communal sharing as a risk-pooling system. They argued that free-riders who enjoy
sharing of meat that other members have acquired but refuse to share their own
acquisitions can potentially destroy the egalitarian-sharing system, which is a public
good (“social insurance”) sustained only by members’ cooperation. Surprisingly, theEvolutionary Perspectives on Group Dynamics 25
simulation results showed that egalitarian sharing norm can evolve robustly under
uncertainty while overcoming the free-rider problem. This implies that our minds arebuilt to be highly sensitive to cues of uncertainty in resource acquisition. Kameda,
Takezawa, Tindale and Smith (2002) showed that such uncertainty cues promoted
people’s willingness to share with others beyond their personal distributive ideologies.

(3) Status
Our ancestors were living in increasingly large and complex social groups
over evolutionary time and as a result there would have been intense competition for
scarce resources such as food, water, and sexual mates (Dunbar, 2004). This
competition paved the way for the emergence of status hierarchies whereby people’s
status would determine their access to reproductively relevant resources. To negotiate
one’s position in the group hierarchy would require specialized mechanisms forassessing one’s relative status as well as mechanisms for climbing up the grouphierarchy and for maintaining a high status position (once obtained).
Status signaling. Humans have likely evolved a set of adaptations to signal
their relative status to others. For instance, they display non-verbal signals such as a
firm handshake or a poised posture to let others know that they hold a high status
position and deserve respect. High status individuals also walk faster (Schmitt &Atzwanger, 1995) and are more likely to tell other people what to do (Forsyth, 2010).
When people seek status they speak clearly and loudly, take more initiatives inconversations, and focus attention on their personal achievements. Just like theirprimate cousins, high status individuals have attention holding power, meaning thatthey are the focus of attention in groups (Keltner et al., 2000). Along with otherprimates humans also have elaborate differentiated behavioural patterns forEvolutionary Perspectives on Group Dynamics 26
interacting with other individuals of higher or lower status than them. High statuscompetitors are treated with respect, whereas low status competitors are treated insubmissive ways (Brosnan et al., 2009; De Waal, 2006).
Status emotions. Humans have also likely evolved a set of specific statusrelated emotions. When people experience a status gain -- for example, winning anaward -- they tend to feel pride and when they experience a loss in status -- forexample, making a stupid remark -- they tend to feel shame (Tracey, 2004). Similarly
people can feel a vicarious sense of pride or shame when the group or team that they
identify with experiences a status gain or loss -- for example winning or losing asports competition. Such emotional experiences are likely to be accompanied byhormonal fluctuations in testosterone, a physiological status marker. In a study amongchess players the winners experienced an increase in testosterone whereas the losers
experienced a decrease (Mazur, Booth, & Dabbs, 1992).
Self-esteem. Humans are also likely to have evolved mechanisms for internallymonitoring one’s status position. Self-esteem might be an internal gauge of anindividual’s relative status. When people feel valued by their peers their self-esteem
goes up and when they feel devalued or ostracized their self-esteem goes down(Williams, 2009). Self-esteem likely functions as a sociometer that monitors people’s
standing in a group and motivates action when people feel their status is being
threatened (Leary & Baumeister, 2000). When people find themselves in a low status
position without having the resources to climb up the hierarchy they might become
depressed. Depression can be thought of as an adaptive response to avoid statuscompetitions with peers (Gilbert, 1992).
From an evolutionary perspective it would be good to draw a distinction
between different forms of self-esteem which reflect different status problems

Evolutionary Perspectives on Group Dynamics 27(Kirkpatrick & Ellis, 2004). For example, concerns about one’s standing as a potential
sexual mate might be quite independent from concerns about being a respected groupmember or concerns about the standing of one’s group (cf. individual vs. collective
self-esteem).
Competitive altruism. It has been suggested that humans are helpful toward
each other because by doing so they receive status benefits. This phenomenon iscalled competitive altruism (Hardy & Van Vugt, 2006; Roberts, 1998). Experimental
research suggests that generous individuals receive more status and are preferred asgroup leaders (Hardy & van Vugt, 2006). Computer simulations show that when
agents can freely interact with each other and each individual gets a status score (animage score) -- which indicates whether they cooperated or defected in previous
interactions -- cooperation becomes the norm (Nowak & Sigmund, 2005). Evidence
for competitive altruism has been found in several other primate species (Brosnan etal., 2009).
Competitive altruism requires psychological mechanisms for monitoring one’s
own relative status and mechanisms for improving it. Research suggests that whenpeople think they are being watched by others, thus their status is being assessed, they
become more generous (Bateson, 2006; Hardy & Van Vugt, 2006) – even a pair ofeyes on the computer screen makes people behave more generously (Haley & Fessler,
2005). In addition, status concerns increase people’s willing to preserve theenvironment and engage in bystander helping (Griskevicius et al., 2010). Men become
especially generous when they are being observed by an attractive female (Iredale etal., 2008).

(4) Group Cohesion

Evolutionary Perspectives on Group Dynamics 28
One of the main problems for ancestral human groups would have been to
maintain cohesion (Dunbar, 2004). Cohesion has been defined as ”the result of all theforces acting on people to remain in their group” (Festinger, 1950). In light of theimportance of staying together as a unit in a hostile savannah environment we would
expect our ancestors (as well as other social species) to have evolved various
mechanisms to preserve social cohesion. Furthermore, as human social networks
increased in size over the course of human evolution we would expect these bonding
mechanisms to have become increasingly sophisticated. To maintain group cohesion
would require specialized mechanisms to recognize oneself and others as belonging to
the same tribe as well as mechanisms to feel emotionally connected with others inincreasingly large groups. Here we discuss a few adaptive mechanisms.
Social identity. Thinking of people who are not necessarily around all the time
as belonging to the same group as you requires the capacity for symbolic thought
whereby symbols such as language or rituals become markers of shared groupmembership. A symbolic social identity allowed our ancestors to connect with a large
network of individuals that were spread around a particular area and this may havebeen quite helpful in sharing resources as well as in competing with other groups.
Research shows that human social identity is highly tribal and that people
spontaneously make us vs. them categorizations (Tajfel & Turner, 1979). Groups withhighly identifying members are also more cohesive (Jetten et al., 1996).
Preserving group cohesion also requires a sense of group loyalty whereby
individuals are prepared to forego attractive alternatives for staying with a group. A
sense of loyalty is deeply ingrained in human psychology. Whenever individuals
highly identify with a group they develop strong feelings of group loyalty which

Evolutionary Perspectives on Group Dynamics 29
increases the attractiveness of their group membership at the costs of alternatives(Van Vugt & Hart, 2004).
Religion, music, dance and laughter. Humans have many specialized
behavioural mechanisms for fostering group cohesion which may have evolutionary
roots. Religion, for instance, is an effective method to promote cohesion between
strangers and mobilize them for joint action on behalf of a group (Atran, 2002).
Religious individuals are more likely to make costly sacrifices on behalf of the groupand the costlier the religious rituals the more cohesive and enduring the religious
group is (Sosis, 2003). Religious people are also happier and they live longer becauseof the adaptive benefits of religion and because religious beliefs are found in all
cultures and societies it has been speculated that religion is a biological adaptation.
Similarly, dance and music have ancient roots. According to evolutionary
anthropologists they may have evolved as group level adaptations for connecting
large networks of genetic strangers (Dunbar, 2004). Like religion, dance and music
are universal phenomena and engaging in these activities releases endorphins in thebrain which makes people feel happy and connected.
Another evolved mechanism for fostering group cohesion is laughter.
Laughter is a highly automatic and contagious phenomenon which can quickly spread
positive emotions through a crowd. Our closets primate cousins, chimpanzees, havelaughter (Provine, 2000). Research suggests that humans readily laugh and thatlaughter reduces stress levels and makes people feel better. Furthermore, laughing
together has been found to increase trust and cooperation between strangers (Van
Vugt et al., 2010).

(5) Collective Decision making

Evolutionary Perspectives on Group Dynamics 30
Humans are adept at organizing concerted efforts. Utilizing group members’various cognitive as well as physical resources efficiently by careful coordination is acore feature of human capacities, supported by the language faculty. Group decision
making is a representative example of such coordination.
Animal group decision making. Recent evidence in behavioural ecology
suggests that “group decision making” is not exclusively human (Conradt & List,
2009). Seeley (1995) provides a review of honey-bee “group decision making.” In latespring or early summer when a colony of bees divides to find a new nest, several
hundred bees fly out as “scouts” to inspect potential nest sites. Upon returning to thecurrent nest, these scout bees perform waggle dances to advertise any good sites they
have discovered and their locations; the duration of the dance depends on the scouts’
perception of the site’s quality (the better the site, the longer the dance). Because
other bees are more likely to visit and inspect the sites advertised by scout bees, highquality sites receive more subsequent visits and advertisements. Such a positive
feedback loop eventually leads to a “group consensus” about the best site.
Although honey-bee “group decision making” may look more like anautomated self-organization than a deliberate coordination, the social-aggregation
processes (advertising a favourable site through waggle dances to recruit more fellow
searchers) are in fact highly coordinated. Even though honey bees do not rely on
language or formal voting for aggregation, they can achieve a group-level“consensus” efficiently. And, most importantly, the bees usually can choose the best
site, a phenomenon called the “wisdom of the hive” (Seeley, 1995). Evidently, somewell-structured social-coordination mechanisms that yield collective wisdom are an
outcome of natural selection.

Evolutionary Perspectives on Group Dynamics 31
Despotism vs. democracy. Then, what is the key evolved decisional structurethat enables collective wisdom in honey bees and in some other animals? Conradt andRoper (2003) compared two contrasting structures, “despotism” and “democracy”, inthe animal kingdom (cf. Van Vugt, 2009). Using a stochastic model, they showed that
democratic decisions can yield better fitness outcomes to group members thandespotism; even when the despot is the most experienced group member, it pays othermembers to accept its decision only when group size is small and the difference ininformation is large. Conradt and Roper (2003) argued that democratic decisions are
more beneficial “primarily because they tend to produce less extreme decisions, rather
than because each individual has an influence on the decision per se” (p.155).
Hastie and Kameda (2005) extended these ideas to human group decision
making. Most naturally-occurring environments for humans as well as animals arecharacterized by large statistical uncertainties. These uncertainties affect many key
decisions, including choice of foraging/nest sites, choice of travel routes, monitoringof predators, and so on (Kameda & Nakanishi, 2002, 2003). Given that no single
individual (despot) can handle these uncertainties alone even though he/she is highly
experienced, the more viable and reliable (“less extreme”, Conradt & Roper, 2003)
decisional structure in the long run is to use groups as an aggregation device. By
aggregating members’ opinions, random errors in individual perceptions under
uncertainty are cancelled collectively, as implied by the law of large numbers instatistics (Surowiecki, 2004). Hastie and Kameda (2005) compared several decisionrules, which differed in computational loads, in terms of their net efficiencies under
uncertainty. These included the Best Member Rule (“despotism”) and the
Majority/Plurality (“democracy”) rules. Results from both computer simulations andlaboratory experiment showed that the Majority/Plurality rule fared quite well,Evolutionary Perspectives on Group Dynamics 32
performing at levels comparable to much more computationally-taxing rules.
Furthermore, the Majority/Plurality rule outperformed the despotic Best Member rule,even when members were not forced to cooperate for group endeavour and free-riding
was possible (Kameda, Tsukasaki, Hastie and Berg, in press).
The robust beauty of majority rules. These results indicate that, despite its
computational simplicity, the Majority/Plurality rule can achieve surprisingly highlevels of performance. Such observations may explain the popularity of the
Majority/Plurality rule across the full spectrum of human groups from hunter–gatherer
and tribal societies (Boehm, 1996) to modern industrial democracies (Davis, 1973;
Devine, Clayton, Dunford, Seying & Pryce, 2001; Kerr & Tindale, 2004), as well as
the animal cases in which democratic decisions are often more beneficial thandespotism (Conradt & Roper, 2003; Conradt & List, 2009). Of course,
phylogenetically, humans are quite distantly related to honey-bees and other “lower”
species. Yet, the striking similarities in decision styles between the two most social
species on the earth suggest that humans and honey-bees have evolved structurally
similar group aggregation mechanisms (i.e., utilizing the law of large numbers) tosolve similar adaptive problems (e.g., foraging). Dealing with uncertainty is the key
challenge underlying the evolution and use of these mechanisms.

(6) Intergroup Relations
A final problem that our ancestors faced was how to deal with members ofother groups. As population densities increased in human evolution so did thecompetition for scarce resources and early human groups increasingly came into
contact with members of rival groups. On the one hand, relations with outgroups
provided opportunities for sharing resources such as food, mates, and information. On

Evolutionary Perspectives on Group Dynamics 33
the other hand, intergroup relations could be a source of tension and conflict overscarce resources. As a consequence, humans likely possess highly specializedmechanisms that enable them to reap the benefits of intergroup relations while
avoiding the costs.
Fear of strangers. As part of this evolved intergroup psychology humans are
relatively suspicious or even fearful of strangers. Fear of strangers is an innate
response which is seen among young children. Fear is strongest toward outgroupmales presumably because they constituted a considerable physical threat in ancestral
times (Navarrete et al., 2010). Outgroups not only posed a significant physical threat
in ancestral environments but also a disease threat (think of the spread of contagious
diseases). Hence, fear of strangers might also serve the function of avoiding
pathogens. A recent study showed that ethnocentrism is strongest among women who
are at the early stage of pregnancy presumably because they are most at risk ofcatching a disease (Navarrete et al., 2007).
Intergroup aggression and warfare. An adaptive solution to intergroupcompetition is the ability to engage in organized violence against members ofoutgroups. Intergroup aggression is common in humans and it also found in otherprimates, including chimpanzees (Brosnan et al, 2009). Humans and chimpanzees use
coalitional aggression to gain access to reproductively relevant resources such as
territories and sexual mates. In both species such coalitions usually consist of males,arguably because males have more to gain from participating in intergroup conflict –we have dubbed this the male warrior effect (Van Vugt, 2009). Research on the malewarrior hypothesis shows that men are more tribal than women: They are moreaggressive in intergroup encounters and have a stronger inclination to infrahumanize
outgroup members. Men are also more likely to make sacrifices on behalf of their

Evolutionary Perspectives on Group Dynamics 34
group during intergroup conflict (Van Vugt et al., 2007). Consistent with the warfare
hypothesis, a recent study suggests that physically formidable men have a stronger
preference for intergroup aggression and warfare (Sell et al., 2009).
Peacemaking and reconciliation. In past environments intergroup relations
also provided opportunities for trading and so it is likely that humans also have
evolved mechanisms for engaging in peaceful interactions with outgroups provided
that they do not pose a physical or disease threat. For instance, members of high statusgroups readily offer help to members of low status outgroups especially whenintergroup helping reaffirms the status difference between the groups (dependency vs.
autonomy helping: Nadler, 2002). People tend to be more forgiving of moraltransgressions from outgroup members than ingroup members (Sturmer & Snyder,2008). Finally, even after a lethal intergroup conflict such as the Rwandan genocide
reconciliation efforts between the groups seem to bear fruit (Paluck, 2009). From an
evolutionary perspective, we expect that women have a particularly important role inpeacekeeping between groups because they are less tribal and possess superior
empathic skills (Van Vugt, 2006).

The Promise of an Evolutionary Science of Group Dynamics

An evolutionary approach to group dynamics can be fruitful in at least four different
ways. First, an evolutionary perspective can provide a more complete understandingof particular group processes by asking fundamental questions about the functions,origins and evolution of these phenomena. A more complete account inevitably
follows from rigorous attempts to establish conceptual linkages between evolutionary

Evolutionary Perspectives on Group Dynamics 35
processes operating on ancestral populations and psychological processes operating
within contemporary groups.
Second, an evolutionary perspective can help overcome biases and blind spots
in the study of groups. It strikes us as odd that the social psychological literature ongroup decision-making often focuses on what is wrong with groups, disregarding thefact that the group is the natural environment for humans (Caporael, 1997; Wilson etal., 2008). Examples include research on groupthink, brainstorming, grouppolarization, and information sharing. A cursory reading of these literatures all too
easily suggests that people are poor collective decision-makers (Wilson et al., 2008).
Any such conclusion, however, is inaccurate (or, at the very least, overly simplistic),
and we believe that an evolutionary perspective can produce more sophisticated andaccurate conclusions about group decision-making (Kameda & Tindale, 2006).
Third, an evolutionary approach is useful in yielding novel hypotheses about
traditional group phenomena. For example, Kenrick, Griskevicius, and colleagues
have applied evolutionary reasoning to produce a number of new hypotheses aboutgroup phenomena such as status, conformity, and social influence that are unlikely tohave been stimulated by other theoretical frameworks (Griskevicous et al., 2007;
Kenrick, Li, & Butner, 2003; Sundie, Cialdini, Griskevicius, & Kenrick, 2006).
Finally, an evolutionary approach can expand the boundaries of scientificinquiry on group dynamics by suggesting important group phenomena that havepreviously received little if any attention from group researchers. Laughter, language,
gossip, dance, music, sports, culture, and religion are increasingly being understood asgroup-level adaptations, that is, as manifestations of psychological processes thatconnect individuals to each other in large and diverse groups, and these insights haveEvolutionary Perspectives on Group Dynamics 36
benefited from evolutionarily-informed inquiry (Atran & Norenzyan, 2004; Dunbar,
2004; Van Vugt et al., 2010).
In short, an evolutionary perspective reinforces our awareness that groupdynamics are fundamental to the study of human nature. Furthermore, it provides aset of conceptual and empirical tools that can be used to understand and describe
group processes more completely and accurately.

Evolutionary Perspectives on Group Dynamics 37
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Figure. Drawings or Pictures of Key Adaptive Group Challenges???