Variations in limited resources allocation towards friends and strangers in children and adolescents from seven economically and culturally diverse societies.

Humans are unique among primates in altruism and sharing limited recourses towards non-kin. Our study revealed the differences in proportions of individuals ready to share limited resources with virtual friend compared to virtual stranger in children and adolescents from seven ethnic groups, represented by four traditional rural African societies from Tanzania with different types of economy and three societies from Russia. The study was conducted between 2015 and 2020, and the data on 2253 individuals (1104 males and 1149 females) were obtained. Six economic games with limited resource allocations were conducted: Prosocial, Envy, and Sharing games with imagined friends and stranger partners accordingly. All players were later classified according to their decisions in all six games into four behavioral types: egoistic, egalitarian, altruistic, and mixed. The effects of population origin, gender, age, and stranger/friend type of interaction on the behavior were estimated by multinomial logistic regression. It was demonstrated that more respondents prefer altruistic and egalitarian behavior than egoistic and mixed in the whole sample. However, significant parochial effect was found. The study revealed significant main effects of ethnicity, age, and the interaction effects of ethnicity and parochial tendencies, and ethnicity and age on the behavior of players.