Egalitarianism, pursuit for equality, and altruism are the most important evolutionarily stable strategies in the human society. This study presents data on the results of economic games for sharing with a potential friend or unfamiliar peer in three ethnic groups of East Africa (Hadza, Iraqw, and Meru). The total sample was 583 children and adolescents; mean age, 13.5 ± 3.1 years. In addition, DNA analysis was carried out and the OXTR gene rs53576 single nucleotide polymorphism was genotyped for 162 Meru individuals. The pronounced individual variability in making decisions on sharing with a potential partner was established. Children and adolescents behaved altruistically towards friends significantly more frequently as compared with strangers. Carriers of the OXTR rs53576 GG variant displayed altruism significantly more frequently both to friends (U = 3376.500, p = 0.047; OR = 3.075, p = 0.032) and to strangers (U = 3478.000, p = 0.025; OR = 3.133, p = 0.007). Significant intergroup differences in egalitarianism, egoism, and altruism were also demonstrated. Data obtained suggest a positive group selection towards altruists.
Keywords: Hadza; Iraqw; Meru; OXTR gene rs53576 SNP; altruism; egalitarianism; egoism; evolutionary stable strategies.