Determinants of fair behavior. An evolutionary perspective and some experimental evidence from Guinea

Undoubtedly, fairness is an essential normative concept in humans and promotes cooperation in human societies. The fact that fairness occurs is however puzzling as it works against the short-term interests of individuals. Theories of genetic evolution, cultural evolution and gen-culture coevolution identify plausible mechanisms for the evolution of fairness in humans. Such mechanisms are kin selection, the support of group beneficial moral norms through ethnic markers, free partner choice with equal outside options, free partner choice with reputation as well as spite in small populations. Here, we present the results of a common resource game field experiment on fair sharing. Based on 37 villages of a multi-ethnic, 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 enforce individual's fair behavior in situations lacking the opportunity to build a positive reputation varied significantly.