Аннотация:Wide range of group factors is of particular interest since they are the most significant reason for thedifferentiation of human economic behavior between two poles—altruism and egoism. This studypresented the results of experiments aimed to investigate how group composition (heterogeneous vs.homogeneous in terms of a group members’ gender) affected cooperation and group outcome. Applyingthe methodology of experimental economics and social psychology, we found that heterogeneous groupswere most effective in terms of cooperation.