A cross-national analysis of sex differences in prisoner's dilemma games.

In a comprehensive cross-national study involving samples from 12 different countries that were representative for the adult populations in terms of age and sex (N = 2,429), we found that women cooperate significantly less overall than men in fully incentivized one-shot prisoner's dilemma games. This gender gap in cooperation can be explained by the fact that women hold lower expectations regarding the cooperativeness of their anonymous interaction partners. These results contradict both the common stereotype that women are more communal, caring, emotionally expressive, and warm than men and substantial empirical evidence showing that women act more prosocially in many contexts.