We begin our commentary by summarizing the commonalities and differences in cognitive phenomena across cultures, as found by the seven papers of this topic. We then assess the commonalities and differences in how our various authors have approached the study of cognitive diversity, and speculate on the need for, and potential of, cross-disciplinary collaboration.

In our response to the 27 commentaries, we refine the theoretical claims, clarify several misconceptions of our framework, and explore substantial disagreements. In doing so, we show that our framework accommodates multiple historical scenarios; debate the historical evidence, particularly about “pre-Axial” religions; offer important details about cultural evolutionary theory; clarify the termprosociality;and discuss proximal mechanisms. We review many interesting extensions, amplifications, and qualifications of our approach made by the commentators.

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)

Many accounts of ethnic phenomena imply that processes such as stereotyping, essentialism, ethnocentrism, and intergroup hostility stem from a unitary adaptation for reasoning about groups. This is partly justified by the phenomena’s co-occurrence in correlational studies. Here we argue that these behaviors are better modeled as functionally independent adaptations that arose in response to different selection pressures throughout human evolution. As such, different mechanisms may be triggered by different group boundaries within a single society. We illustrate this functionalist framework using (...) ethnographic work from the Quechua-Aymara language boundary in the Peruvian Altiplano. We show that different group boundaries motivate different ethnic phenomena. For example, people have strong stereotypes about socioeconomic categories, which are not cooperative units, whereas they hold fewer stereotypes about communities, which are the primary focus of cooperative activity. We also show that, despite the cross-cultural importance of ethnolinguistic boundaries, the Quechua-Aymara linguistic distinction does not strongly motivate any of these intergroup processes. (shrink)