Why Males Are More Violent

Virtually all of the warriors across history have been male, from tribal to modern times. Similarly, males have perpetrated most of the interpersonal violent crimes: in the U.S., 90% of murderers and 82% of other violent criminals are male. Males even commit suicide four times as often as females.1 The difference in male violence is usually ascribed to inherited biology-mainly to adult males having 20 times as much testosterone as females.2 The problem with this theory is that boys actually have the same testosterone levels as girls until they are about eight years old, whereas beginning in about their fourth year of life boys begin acting more violent and domineering than girls, forming structured dominance hierarchies rather than the smaller, more sharing networks formed by girls.3 Indeed, some studies-such as a recent one in Canada measuring hitting, biting and kicking-show little difference in boys and girls violent behaviors until the boys' testosterone increases after ten years of age.4 However, careful studies have shown "no evidence of an association between testosterone and aggression in teenage boys."5 Indeed, some studies have concluded that "testosterone efficiency is more often associated with aggression than is testosterone excess. When some men have had their testosterone lowered artificially or by castration, their aggression actually increases."6 Indeed, testosterone levels actually plummet under stressful conditions, such as military combat.7 Goldstein summarizes the findings on testosterone: "The relative unimportance of testosterone in causing aggression is seen from the fact that differences in testosterone levels between individuals do not predict subsequent differences in their aggressive behavior-nor do short-term fluctuations in a man's testosterone level predict changes in his levels of aggression." And Boyd simply concludes from his thorough study that there is "no relationship between testosterone levels and being of a violent disposition."9

Nor do lower testosterone levels in adult women prevent them from voting for war leaders and favoring military solutions nearly as often as men-indeed, somewhat more women than men regarded the Soviet threat as requiring military response by the U.S.10 Although more men than women approved of the Gulf War, more women than men thought George Bush's hyper-military policies in Iraq were a good way to protect the U.S. from terrorism, mainly because they were "security Moms" who believed Bush would...