On dit depuis longtemps que l'image visuelle est un langage. Mais ne s'agit-il là que d'un slogan? Ce langage a-t-il des mots? A-t-il une syntaxe? S'écrit-il? Se subdivise-t-il en langues? Permet-il ce jeu sur les formes et le sens qu'on appelle rhétorique? C'est ce qu'on ne savait guère jusqu'ici.

Background. Sport training has an impact on other sciences. Among these sciences is physiology, in which emerged to form what is called sports physiology. The recent development in the science of physical education is one of the important factors in measuring and determining the nature of athletes' physical, physiological and biochemical adaptations and responses. The blood circulatory system is important as manifested in finding the relationship between some blood groups and the basic physical characteristics and the completion of the (...) 100-meter race. Objectives. The aim of this study is to identify the types of blood groups and their relationship to some physical traits, and the completion of the 100-meter race for some student athletes. Methods. the descriptive approach was used for its suitability to the research problem. The sample consisted of the students of second stage in the Department of Physical Education and Sports Sciences at Al-Mustaqbal University in Iraq. It was 143 students (35%) of the original research sample. With the a 143 sample size, the calculated confidence is 34.95 with standard deviation of ±3.87. Results. The study finds out a positive correlation between blood groups and some physical traits. There is also a positive correlation between blood groups and 100-meter sprint achievement as indicated from the statically data analysis and supported by the mean values 5.6 for O blood grouping. Conclusion. the blood group of athletes can take a role and impact on the speed and muscular strength tests. according to the results of this study the athletes who have AB and O blood group are more likely to win in 100 sprint races. (shrink)

Most commentators supported the thesis of the target article, though there were also those who were less fully persuaded. I will begin with a response to the most critical commentaries. First, I will justify an evolutionary perspective that includes group organization and nongenetic inheritance. Next, I will discuss the concept of emergence. Following that, I will transition to an exploration of ideas and concerns brought up by some of the more supportive commentators. This will include a discussion of different types (...) of groups; the psychology of group-level traits; the uses and limitations of an institutional perspective; the link between transmission, adaptation, and selection; current and future methodologies; and the variety of fields that may benefit from a group-level traits perspective. (shrink)

Psychological research on social influence illuminates many mechanisms through which role differentiation and collaborative interdependence may affect cultural evolution. We focus here on psychological processes that produce specific patterns of asymmetric influence, which in turn can have predictable consequences for the emergence and transmission of group-level traits.

Friendship establishment was analyzed using constructs from social cognitive theory and social network theory. In further studies, we investigated the effect of personality traits, interpersonal self-efficacy, and network structure on the establishment of friendships. In this study, we used social network analysis method and exponential random graph model. The following findings are reported. First, the friendship network of college students had small group characteristics, and the formation of this small group was more based on personality complementarity than similarity. The homogeneity (...) hypothesis of personality was not tenable. Secondly, individuals with dominance or influence personality traits and high interpersonal self-efficacy were more likely to be in the center of the friendship network. Furthermore, personality traits and interpersonal self-efficacy may have interactive effects on the formation of friendship networks. Popularity and activity effects existed in friendship networks, but the reciprocal relationship based on personality traits was not verified. The balance structure can easily explain the agglomeration of friendships in a small range, indicating that small groups of friendships prefer a two-way circular close relationship. Finally, the formation of a friendship network includes the comprehensive process of individual characteristics and endogenous tie formation, which helps us to understand the social population structure and its process over a wider range. (shrink)

Empathy is sharing and understanding others’ emotions. Recently, researchers identified a culture–sex interaction effect in empathy. This phenomenon has been largely ignored by previous researchers. In this study, the culture–sex interaction effect was explored with a cohort of 129 participants (61 Australian Caucasians and 68 Chinese Hans) using both self-report questionnaires (i.e., Empathy Quotient and Interpersonal Reactivity Index) and computer-based empathy tasks. In line with the previous findings, the culture–sex interaction effect was observed for both trait empathy (i.e., the (...) generalized characteristics of empathy, as examined by the self-report questionnaires) and state empathy (i.e., the on-spot reaction of empathy for a specific stimulus, as evaluated by the computer-based tasks). Moreover, in terms of state empathy, the culture–sex interaction effect further interacted with stimulus traits (i.e., stimulus ethnicity, stimulus sex, or stimulus emotion) and resulted in three- and four-way interactions. Follow-up analyses of these higher-order interactions suggested that the phenomena of ethnic group bias and sex group favor in empathy varied among the four culture–sex participant groups (i.e., Australian female, Australian male, Chinese female, and Chinese male). The current findings highlighted the dynamic nature of empathy (i.e., its sensitivity toward both participant traits and stimulus features). Furthermore, the newly identified interaction effects in empathy deserve more investigation and need to be verified with other Western and Asian populations. (shrink)

Human cooperation is highly unusual. We live in large groups composed mostly of non-relatives. Evolutionists have proposed a number of explanations for this pattern, including cultural group selection and extensions of more general processes such as reciprocity, kin selection, and multi-level selection acting on genes. Evolutionary processes are consilient; they affect several different empirical domains, such as patterns of behavior and the proximal drivers of that behavior. In this target article, we sketch the evidence from five domains that bear (...) on the explanatory adequacy of cultural group selection and competing hypotheses to explain human cooperation. Does cultural transmission constitute an inheritance system that can evolve in a Darwinian fashion? Are the norms that underpin institutions among the cultural traits so transmitted? Do we observe sufficient variation at the level of groups of considerable size for group selection to be a plausible process? Do human groups compete, and do success and failure in competition depend upon cultural variation? Do we observe adaptations for cooperation in humans that most plausibly arose by cultural group selection? If the answer to one of these questions is “no,” then we must look to other hypotheses. We present evidence, including quantitative evidence, that the answer to all of the questions is “yes” and argue that we must take the cultural group selection hypothesis seriously. If culturally transmitted systems of rules (institutions) that limit individual deviance organize cooperation in human societies, then it is not clear that any extant alternative to cultural group selection can be a complete explanation. (shrink)

Many of the most important properties of human groups – including properties that may give one group an evolutionary advantage over another – are properly defined only at the level of group organization. Yet at present, most work on the evolution of culture has focused solely on the transmission of individual-level traits. I propose a conceptual extension of the theory of cultural evolution, particularly related to the evolutionary competition between cultural groups. The key concept in this extension is (...) the emergent group-level trait. This type of trait is characterized by the structured organization of differentiated individuals and constitutes a unit of selection that is qualitatively different from selection on groups as defined by traditional multilevel selection theory. As a corollary, I argue that the traditional focus on cooperation as the defining feature of human societies has missed an essential feature of cooperative groups. Traditional models of cooperation assume that interacting with one cooperator is equivalent to interacting with any other. However, human groups involve differential roles, meaning that receiving aid from one individual is often preferred to receiving aid from another. In this target article, I discuss the emergence and evolution of group-level traits and the implications for the theory of cultural evolution, including ramifications for the evolution of human cooperation, technology, and cultural institutions, and for the equivalency of multilevel selection and inclusive fitness approaches. (shrink)

Following Smaldino's definition, we claim that language is also an emergent group-level trait, and propose two facets to verify this statement, both of which also provide a general framework to address the future work about group-level traits.

A body of work in ethics and epistemology has advanced a collectivist view of virtues. Collectivism holds that some social groups can be subjects in themselves which can possess attributes such as agency or responsibility. Collectivism about virtues holds that virtues are among those attributes. By focusing on two different accounts, I argue that the collectivist virtue project has limited prospects. On one such interpretation of institutional virtues, virtue-like features of the social collective are explained by particular group-oriented features (...) of individual role-bearers that are elicited by institutional structures or goals. On another account of groups as moral agents unbound by formal institutional constraints, to the extent that group characteristics meet the collectivist requirement, they fail to stand up as virtues in the substantive sense of a character trait. These two positions’ respective drawbacks and insights support a non-collectivist conclusion: Where there is a substantive virtue of some social group, it consists only in certain group-specific attitudes and motives of individuals qua members of that group. I end by outlining some risks in adopting collectivism about virtues as an explanatory or normative doctrine, and suggesting that we can abandon it without embracing an equally undesirable individualism in virtue theory. (shrink)

Are humans genetically predisposed to exhibit prosocial behaviours? Elliott Sober and David Sloan Wilson have made major contributions to our understanding of this question. In my remarks here I will propose a revision in their definition of altruism, suggest a broader term, ‘prosociality', to account for cooperation in humans, and present evidence for a particular set of human prosocial traits that likely evolved with our species and may account for our unique ability to maintain intricate cooperative networks not based on (...) ties of kinship. (shrink)

Adaptations can occur at different hierarchical levels (e.g., cells and multicellular organisms), but it can be difficult to identify the level(s) of adaptation in specific cases. A major problem is that selection at a lower level can filter up, creating the illusion of selection at a higher level. We use optimality modeling of the volvocine algae to explore the emergence of genuine group (i.e., colony-level) adaptations. We find that it is helpful to develop an explicit model for what group fitness (...) would be in the absence of group-level relationships between traits and group fitness. We call this “counterfactual fitness,” because in many actual cases of interest there are group-level relationships. Once counterfactual fitness is modeled, the difference between effects that filter up and genuine group selection is explicit and so, therefore, is the distinction between apparent and genuine group adaptations. We call the latter group-specific adaptations. Recognizing group-specific adaptations is important because only group-specific adaptations would cause the lower-level units (cells in this case) to be maladapted if they were to leave the group and enter a global cell-level population. Thus, as group-specific adaptations evolve, they create selective pressure for increased cohesiveness and individuality of groups. This article suggests that group-specific adaptations could be present in the simplest, earliest branching colonial volvocine species, which do not have distinct specialized cells. The article also makes predictions about the kind of empirical evidence needed to support or refute the hypothesis that a particular trait is a group-level adaptation. (shrink)

In the scientific literature on religious evolution, two competing theories appeal to group selection to explain the relationship between religious belief and altruism, or costly, prosocial behavior. Both theories agree that group selection plays an important role in cultural evolution, affecting psychological traits that individuals acquire through social learning. They disagree, however, about whether group selection has also played a role in genetic evolution, affecting traits that are inherited genetically. Recently, Jonathan Haidt has defended the most fully developed account based (...) on genetic group selection, and I argue here that problems with this account reveal good reasons to doubt that genetic group selection has played any important role in human evolution at all. Thus, considering the role of group selection in religious evolution is important not just because of what it reveals about religious psychology and religious evolution, but also because of what it reveals about the role of group selection in human evolution more generally. (shrink)

The reproduction of cultural systems in cases where cultural group selection may occur is typically incomplete, with only certain cultural traits being adopted by less successful cultural groups. Why a particular trait and not another is transmitted might not be explained by cultural group selection. We explore this issue through the case of religious syncretism.

Philosophical reflection on transparency, including group transparency, is beginning to gain steam. This paper contributes to this work by developing a conceptualization of transparency as an intellectual character trait that groups can possess, and by presenting a novel argument for thinking that such transparency should be understood along non-summativist lines. According to the account offered, a group’s being intellectually transparent consists in the group’s tending to attend well to its perspective and to share its perspective faithfully with others (...) in order to promote their epistemic goods. It is argued that this kind of group intellectual transparency, pace summativism, does not always consist merely in group members possessing intellectual transparency. The argument given for this conclusion works differently from existing arguments for non-summativism about group character traits, and it retains persuasive power even if summativist views of most group phenomena, including other group character traits, are correct. (shrink)

In this article I critically examine a standard feature in conceptions of discrimination: the group-criterion, specifically the idea that there is a limited and definablegroup of traits that can form the basis of discrimination. I review two types of argument for the criterion. One focuses on inherently relevant groups and relies ultimately on luck-egalitarian principles; the other focuses on contextually relevant groups and relies ultimately on the badness of outcomes. I conclude that as neither type of argument is (...) convincing, the criterion is morally arbitrary, and as such untenable. Finally, I suggest both some of the conceptual and some of the practical implications of abandoning the criterion. (shrink)

Evolutionary anthropology has focused on the origins of war, or rather ethnocentricity, because it epitomizes the problem of group selection, and because war may itself have been the main agent of group selection. The neo-Darwinian synthesis in biology has explained how ethnocentricity might evolve by group selection, and the distinction between evoked culture and adopted culture, suggested by the emerging synthesis in evolutionary psychology, has explained how it might be transmitted. Ethnocentric mechanisms could have evolved by genetic selection in ancestral (...) hominids, or through the interaction of genetic and cultural selection in modern humans, or both. The existence of similar behaviors in chimpanzees and the parallel development of early human societies around the globe are arguments for such inherited mechanisms. There may have been some adaptive breakthroughs in purely cultural evolution, but this process does not seem likely to produce long-term Darwinian adaptations because of the prolificity of cultural traits. Warfare may once have been a major agent of group selection, but the rates of extinction among human groups are so slow as to render this improbable since the rise of state-level societies, whose warfare tends to become a cyclical balance-of-power situation. Perhaps the most serious implication of current evolutionary thought is that the individualistic model of culture common in the social sciences and humanities is outmoded, and should be replaced by a new model that recognizes the organismic nature of human societies. (shrink)

Studies of group selection have been done with both natural and manipulated populations using plants, insects and birds. Group selection occurred in all studies and often the strength of group selection was equal to that of individual selection. Laboratory selection experiments resulted in the opposite response to individual selection than that predicted. Selection with plants for high leaf area resulted in plants with smaller leaf area and selection for high emigration rate in beetles produced lines with lower rates. The selected (...) traits included interactions among individuals. Theoretical studies have shown that genetically based interactions among individuals can interfere with individual selection. Evolution can be partitioned into selection and the response to selection. A response to selection requires genetic variation. Properties of group genetic structure for the natural populations are discussed. The experimental populations had controlled group structure and demonstrate that populations can respond to group selection under some genetic structures. (shrink)

Reproductive division of labor has been proposed to play a key role for evolutionary transitions in individuality (ETIs). This chapter provides a guide to a theoretical model that addresses the role of a tradeoff between life-history traits in selecting for a reproductive division of labor during the transition from unicellular to multicellular organisms. In particular, it focuses on the five key assumptions of the model, namely (1) fitness is viability times fecundity; (2) collective traits are linear functions of their cellular (...) counterparts; (3) there is a tradeoff between cell viability and fecundity; (4) cell contribution to the collective is optimal; and (5) there is an initial reproductive cost in large collectives. Thereafter the chapter contrasts two interpretations of the model in the context of ETIs. Originally, the model was interpreted as showing that during the transition to multicellularity the fitness of the lower-level (the cells) is “transferred” to the higher level (the collective). Despite its apparent intuitiveness, fitness transfer may obscure actual mechanisms in metaphorical language. Thus, an alternative and more conservative interpretation of the model that focuses on cell traits and the evolutionary constraints that link them is advocated. In addition, it allows for pursuing subsequent questions, such as the evolution of development. (shrink)

Smaldino argues that evolutionary theories of social behavior do not adequately explain the emergence of group-level traits, including differentiation of roles and organized interactions among individuals. We find Smaldino's account to be commendable but incomplete. Our commentary focuses on a simple question that has not been adequately addressed: What is a group?

I admire Wilson & Sober's (W & S's) aim, to alert social scientists that group selection has risen from the ashqs, and to explicate its relevance to the behavioral sciences. Group selection has beenwidely misunderstood; furthermore, both authors have been instrumental in illuminating conceptual problems surrounding higher-level selection. Still, I find that this target article muddies the waters, primarily through its shifting and confused definition of a "vehicle" of selection. The fundamental problem is an ambiguity in the definition of "adaptation." (...) On the one hand, any evolutionary change that results from a selection process could be called an adaptation, by definition; I call this the "weak" view of adaptation. A "strong" view of adaptation, on the other hand, includes some notion of design - the evolution of a specific complex trait understood, in an engineering sense, to provide a mechanism favoring its owner's success in contributing to the evolutionary lineage. (shrink)

ABSTRACT In this paper we deal with Hobbes’s elucidation of the political conflict caused by rebellious groups. First of all, we attempt to prove that groups are important characters in Hobbesian antagonisms. Secondly, it will be argued that the isomorphic structure that underlies all associations is vital to account for these disputes. To wit, the fact that minor corporate bodies are ‘similar’ vis à vis the State leaves a lengthy flank open to rebellion, since this homology may encourage (...) their leaders to compare themselves with the sovereign and to challenge his or her power. Whereas the inclusion of this trait may seem at face value paradoxical to Hobbes’s absolute order project, we shall contend that it is actually a way of ascribing responsibility to the leaders of rebellious groups. Furthermore, as a subsidiary hypothesis, it will be claimed that the centrality of the theory of represented corporations is a result of Hobbes’s aim to erase, not rebellion as such, but only its tumultuous setup. (shrink)

Wilson & Sober's discussion of group selection is marred by the absence of plausible examples of human group-level behavioral adaptation. The trait of authoritarianism is one possible example of such an adaptation. It reduces within-group variance in reproductive success, manifests itself more strongly in response to group-level threat, and is found in a variety of cultures.

In "Some Criticism of the Contextual Approach, and a Few Proposals" in Biological Theory, Brian McLoone discusses some of the points about the contextual approach that I made in a recent paper. Besides offering a reply to McLoone’s comments on my paper, in this article I show why McLoone’s discussion of the two main frameworks for thinking about group selection—the contextual and the Price approach—is partly misguided. In particular, I show that one of McLoone’s main arguments against the contextual approach (...) is missing the target and that one of his (and Elliott Sober’s) arguments in defense of the Price approach is flawed. Criticizing these arguments will help me present an entirely different picture than McLoone’s of the current status of multilevel selection theory. More precisely, I argue that the idea that we are dealing with "multilevel selection" in the type of multigroup cases in which the focal units are the individuals (and their traits) has recently come under threat. Finally, I discuss the ways in which this idea might be salvaged by appealing either to the contextual or to the Price approach. (shrink)

Numerous studies argue that perceived group deprivation is a risk factor for radicalization and violent extremism. Yet, the vast majority of individuals, who experience such circumstances do not become radicalized. By utilizing models with several interacting risk and protective factors, the present analysis specifies this relationship more concretely. In a large United Kingdom nationally representative survey (n= 1,500), we examine the effects of group-based relative deprivation on violent extremist attitudes and violent extremist intentions, and we test whether this relationship is (...) contingent upon several individual differences in personality. The results show that stronger group-based injustices lead to increased support for and intentions to engage in violent extremism. However, some of the effects are much stronger for individuals who exhibit a stronger need for uniqueness and for status and who demonstrate higher levels of trait entitlement. Conversely, several effects are lessened for those individuals high in trait forgiveness, demonstrating a strong capacity for self-control and for those who are exerting critical as well as open-minded thinking styles, thus constituting buffering protective factors, which dampen the adverse effects of perceived group injustice on violent extremism. The results highlight the importance of considering (a) the interaction between individual dispositions and perceptions of contextual factors (b) the conditional and cumulative effects of various risk and protective factors and (c) the functional role of protective factors when risk factors are present. Collectively, these findings bring us one step closer to understanding who might be more vulnerable to violent extremism as well as how. Overall, the study suggests that preventing and countering violent extremism (P/CVE) programs must take account of the constellation of multiple factors that interact with (and sometimes enable or disable) one another and which can be targeted in preventions strategies. (shrink)

Après le rappel de différents contextes dans lesquels a émergé et s’est affirmée en Allemagne au xixe siècle l’idée de philosophie scientifique, l’article a pour objectif une description de la conception de Reichenbach, contrastée avec celle de plusieurs membres du Cercle de Vienne. Je montre en particulier le lien épistémologique et institutionnel entre le groupe de Reichenbach à Berlin et celui de Göttingen autour de Hilbert. J’esquisse aussi un rapprochement entre certains traits caractéristiques de la position de Reichenbach et la (...) conception régionale de l’épistémologie historique française. L’axiomatique et la métamathématique de Hilbert sont bien entendu une racine commune aux orientations suivies par Reichenbach et les épistémologues français des mathématiques. Mais l’impact de la théorie de la relativité, de la mécanique quantique et du calcul des probabilités ne fut pas moins grand et renouvela en profondeur les concepts de temps, d’espace, de substance, de cause et de loi dans une mise en question des thèses du transcendantalisme kantien qui tourna l’intérêt vers les pratiques scientifiques effectives. (shrink)

How do altruistic links affect allocative behavior and wellbeing? Can the processes of transmission and probable acquisition of parental traits result in a stable equilibrium where all agents are altruists? Why do children furnish their parents with attention and care? Does the timing of the intergenerational transfer of the family's productive asset affect the recipient's incentive to acquire human capital? Why do migrants remit? Altruism and Beyond provides answers to these and related questions. In addition, it traces some of the (...) market repercussions of the intrafamilial, intergenerational, and intragroup transfers and exchanges that it models. (shrink)

Petrides et al. (2016) provide a comprehensive overview of research findings relating to trait emotional intelligence. The bulk of findings indicate that trait emotional intelligence is of benefit in a variety of realms, including clinical, health, social, educational, and organizational. Trait emotional intelligence has generally been studied as a quality of individuals. Conceptualizing and studying trait emotional intelligence at a systems level extends the construct and creates a foundation for additional applications and benefits. Systems can include (...) couples, groups, societies, and human–artificial intelligence interaction. (shrink)

During the 1920s and 1930s the testing of blood groups for large numbers of people became a very common practice. Although much of this was to ensure compatibility for blood transfusion, over 1,000 articles were published with results of tests on over 1.3 million people to answer more theoretical, scientific questions. The motivation for much of this research was the possible link between the well established hereditary blood types and other possible inherited traits. Because the existence of the blood (...) groups was a rather sudden discovery, the record of this publication offers an excellent case study of the diffusion of new scientific knowledge. Differences in the beginning of blood group research from country to country reveal some important influences of social setting on the spread and application of the new discoveries. (shrink)

Many psychometricians and behavioral geneticists believe that high heritability of IQ test scores within racial groups coupled with environmental hypotheses failing to account for the differences between the mean scores for groups lends plausibility to explanations of mean differences in terms of genetic factors. This two-component argument cannot be sustained when viewed in the light of the conceptual and methodological themes introduced in Taylor . These themes concern the difficulties of moving from the statistical analysis of variance of (...) observed traits to investigation of measurable genetic factors and measurable environmental factors. One such theme is that quantities estimated by an AOV of observed traits cannot be equated with measurable genetic or environmental factors involved in the development of those traits. Once this distinction is clear, the argument that environmental factors have failed to explain the differences lacks weight because it does not consider whether genetic factors have been more successful. This article exposes additional flaws in the lines of thinking associated with the two-component argument, with the distinction between passive, reactive, and active associations between genetic and environmental factors, and with the reciprocal causation models Dickens and Flynn propose in order to reconcile high estimates of heritability and large IQ test score gains between generations. Human heritability estimates are irrelevant in developing explanations of differences across groups or across generations. My critique is directed at opening up more conceptual space for deriving empirically validated models of developmental pathways whose components are heterogeneous and differ among individuals at any one time and over generations. (shrink)

The debate over group selection shows no signs of abating. If existent, group selection is likely to have significantly reinforced prosocial and altruistic behavior. This article is theoretical and argues that there have been some major lacunae in the debate as concerns humans. The traits that are most uniquely and universally human—such as prolonged rearing of dependent offspring, the family, large-scale, tribal networks, and cultural-linguistic diversity and exclusivity—have been largely overlooked. These most salient and mutually reinforcing human specifics vastly increased (...) individuals' stake in and commitment to ancestral tribal groups. Tribal members were in the same boat, and risked massive fitness loss if it were sunk. This suggests that group selection existed and was much stronger among humans than among any other animal species. (shrink)

Alexithymic traits, which entail finding it difficult to recognize and describe one’s own emotions, are linked with poor trait emotional intelligence and difficulties in identifying and managing stressors. There is evidence that alexithymia may have detrimental consequences for wellbeing and health, beginning in adolescence. In this cross-sectional study, we investigated the prevalence and incidence of alexithymia in teenage girls, testing the statistical power of TEI and student burnout to discriminate between high- and low-alexithymic subjects. A sample of 884 female (...) high school students attending three Italian academic-track high schools completed self-report measures of alexithymia, school burnout, and TEI. Main descriptive statistics and correlational analysis preceded the discriminant analysis. The mean alexithymia scores suggest a high prevalence of alexithymia in female adolescents; as expected, this trait was negatively correlated with TEI and positively associated with school burnout. Participants with high vs. low alexithymia profiles were discriminated by a combination of TEI and burnout scores. High scores for the emotionality and self-control dimensions of TEI were strongly associated with membership of the low alexithymia group; high scores for the emotional exhaustion dimension of school burnout were indicative of membership of the high alexithymia group. These findings suggest crucial focuses for educational intervention: efforts to reduce the risk of emotional exhaustion and school burnout should especially concentrate on enhancing emotional awareness and self-control skills, both strongly associated with low levels of alexithymia. (shrink)

The evolved psychological process for producing social norms is both needed to facilitate emergent group-level traits and capable of delivering such a process. I discuss how this process can work to generate group-level traits and how specific mechanisms established to buttress social norms similarly can explain how group-level traits are supported.

Several researchers have proposed that humans are predisposed to treat ethnic identities as stable and inherent. However, the ethnographic, historical, and genetic records attest to the ubiquity of inter-ethnic migrations across human history. These two claims seem to be at odds. In this article we compare three evolutionary accounts of how people reason about identity stability, and the effect that the cultural evolution of ethnic group boundaries may have on these beliefs. We test our hypotheses among Himba pastoralists in Namibia, (...) whose recent fission from the neighboring Herero makes them ideal for studying the effect of cultural distance on folk beliefs about identity stability. In a vignette experiment, we asked participants whether an individual born in one group who moved to another group would retain their original group membership and cultural characteristics or acquire those of the new group. Across vignette conditions we examine the importance of the direction of migration, parental social influence, and age at migration on perceptions of identity stability. We also compare participant responses to two out-groups, the Herero, and the more distantly related Damara. We find that participants seldom thought of identity as stable or fixed at birth. Furthermore, we show that cultural distance and endogamous preferences are independent of beliefs of identity stability. Himba believed the Damara character was more likely to change identity and cultural traits than was the Herero character, despite their greater cultural distance from the former group, and despite the fact that all participants expressed more anti-Damara than anti-Herero sentiment. (shrink)