Fairness is undoubtedly an essential normative concept in humans and promotes cooperation in human societies. The fact that fairness exists is puzzling, however, because it works against the short-term interest of individuals. Theories of genetic evolution, cultural evolution, and gene-culture coevolution identify plausible mechanisms for the evolution of fairness in humans. Such mechanisms include kin selection, the support of group-beneficial moral norms through ethnic markers, free partner choice with equal outside options, and free partner choice with reputation as well as (...) spite in small populations. Here, we present the results of a common-pool resource game experiment on sharing. Based on data from 37 multiethnic villages in a subsistence agricultural population in Foutah Djallon, Guinea, we show that fair behavior in our experiment increased with increasing ethnic homogeneity and market integration. Group size and kinship had the opposite effect. Overall, fair behavior was not conditional on reputation. Instead, the ability of the different village populations to support individuals’ fairness in situations lacking the opportunity to build a positive reputation varied significantly. Our results suggest that evolutionary theory provides a useful framework for the analysis of fairness in humans. (shrink)

While the existence of human cognitive and behavioral diversity is now widely recognized, it is not yet well established how to explain this diversity. In particular, it is still unclear how to determine whether any given instance of human cognitive and behavioral diversity is due to a common psychology that is merely “triggered” differently in different bio-cultural environments, or whether it is due to deeply and fundamentally different psychologies. This paper suggests that, to answer this question, we need to employ (...) subtle theoretical considerations of theory choice—especially the consideration of the complexity-weighted differential predictive successes of the two accounts. To make this clearer, the paper develops a novel analysis of the observed differences in human sharing dispositions. (shrink)

While the existence of human cognitive and behavioral diversity is now widely recognized, it is not yet well established how to explain this diversity. In particular, it is still unclear how to determine whether any given instance of human cognitive and behavioral diversity is due to a common psychology that is merely “triggered” differently in different bio-cultural environments, or whether it is due to deeply and fundamentally different psychologies. This paper suggests that, to answer this question, we need to employ (...) subtle theoretical considerations of theory choice—especially the consideration of the complexity-weighted differential predictive successes of the two accounts. To make this clearer, the paper develops a novel analysis of the observed differences in human sharing dispositions. (shrink)