Some reflections on sex differences in aggression and violence

Four issues relevant to sex differences in human aggression and violence ar e considered. (1) The motivation for play and serious aggression in childre n and juvenile animals is different. Consequently, the evolutionary explana tions for each may be different. (2) Sex differences in intrasexual aggress ion may be due to effects of the attacker or the target. There is evidence that both males and females are more physically aggressive against males an d less physically aggressive against females. The evolutionary explanation for each component of the sex difference in intrasexual aggression may be d ifferent. (3) Aggression and violence are defined. The former is the attack , and the latter is the consequent injury or death. The evolutionary explan ation for each may not be the same. (4) Most men and women are neither phys ically aggressive nor criminally violent. The evolutionary explanations of sex differences in aggression and violence should take this polymorphism in to account.