Do Men Become Warriors? — An Empirical Test of the Male Warrior Hypothesis

Abstract

This study examines whether men exhibit outgroup aggression in an intergroup situation created in a laboratory setting. According to the male warrior hypothesis, men have psychological mechanisms that allow them to engage in intergroup conflict and outgroup aggression. However, there is little empirical evidence that men behave aggressively toward outgroup members. To test whether men engage in outgroup aggression in intergroup situations, we conducted a laboratory experiment using a modified Intergroup Prisoner’s Dilemma–Maximizing Differences (IPD-MD) game. The game consisted of three pools: ingroup cooperation, outgroup exploitation, and outgroup aggression. Participants decided how much of their endowment to allocate to each pool. We also manipulated whether participants were informed of the group's gender composition prior to the game, testing the theoretical prediction that men are more likely to form coalitions for outgroup aggression. The results showed no gender differences in contributions to the outgroup aggression or exploitation pools, nor was there an effect of the information manipulation. However, both men and women anticipated that outgroup members would engage in outgroup aggression.