group male competition

Evolutionary scientists argue that human cooperation is the product of a long history of competition among rival groups. There are various reasons to believe that this logic applies particularly to men. In three experiments, using a step-level public-goods task, we found that men contributed more to their group if their group was competing with other groups than if there was no intergroup competition. Female cooperation was relatively unaffected by intergroup competition. These findings suggest that men respond more strongly than women to intergroup threats. ..These findings fit nicely with an evolutionary hypothesis about specific male intergroup adaptations—the male-warrior hypothesis—and such evolved intergroup traits are likely to be reinforced through cultural processes, for example, during childhood socialization...Women's social psychology is likely to be shaped more strongly by different kinds of needs, such as defending their offspring and creating supportive social networks