Sexual selection makes men primary targets and agents of intergroup aggression.

Evidence

Such evidence is in accord with the arguments we derived from parental investment theory and sexual selection, namely that men have far more to gain, relative to women, by engaging in competitive and risky status-striving strategies. It has been further argued that these same processes that drive greater intrasexual competition among men within a group can be extrapolated to account for the violent and aggressive intergroup conflict observed among men. That is, the potential benefits associated with intergroup competition are far greater for men than for women, thereby making it more likely that men will serve as the primary targets and agents of intergroup aggression. — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 1210

Categorization

• XREF: This evolutionary-reproductive-competition account of out-group aggression directly complicates purely cognitive or sociohistorical theories of intergroup prejudice in the existing thread.
• corroborated: 2 independent passages support this claim — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 1210