Given what we know about the tendency toward self-enhancement and a desire for status, you will not be surprised to learn that there is a universal tendency for men to be more violent than women (Archer & Coyne, 2005; Crick & Nelson, 2002). In comparison to women and girls, who use more nonphysical and relational aggression such as shouting, insulting, spreading rumors, and excluding others from activities, men and boys prefer more physical and violent aggression—behaviors such as hitting, pushing, tripping, and kicking (Österman et al., 1998).
Strong gender differences in aggression have been found in virtually every culture that has been studied. Worldwide, about 99% of rapes are committed by men, as are about 90% of robberies, assaults, and murders (Graham & Wells, 2001). Among children, boys show higher rates of physical aggression than girls do (Loeber & Hay, 1997), and even infants differ, such that infant boys tend to show more anger and poorer emotional regulation in comparison to infant girls. These findings will probably not surprise you because aggression, as we have seen, is due in large part to desires to gain status in the eyes of others, and (on average) men are more concerned about this than are women.
Although these gender differences exist, they do not mean that men and women are completely different, or that women are never aggressive. Both men and women respond to insults and provocation with aggression. In fact, the differences between men and women are smaller after they have been frustrated, insulted, or threatened (Bettencourt & Miller, 1996). And men and women seem to use similar amounts of verbal aggression (Graham & Wells, 2001).
Gender differences in violent aggression are likely caused in part by hormones. Testosterone, which exists at higher levels in boys and men, plays a significant role in aggression, and this is in part responsible for these differences. And the observed gender differences in aggression are almost certainly due, in part, to evolutionary factors. During human evolution, women primarily stayed near the home, taking care of children and doing the cooking, whereas men engaged in more aggressive behaviors, such as defense, hunting, and fighting. Thus men probably learned to aggress, in part, because successfully fulfilling their duties required them to be aggressive. In addition, there is an evolutionary tendency for males to be more competitive with each other in order to gain status. Men who have high social status are more attractive to women, and having status allows them to attract the most desirable, attractive, and healthy mates (Buss & Shackelford, 1997).
But gender differences are not entirely determined by biology and evolution; many of these differences are the result of social learning. Imagine for a moment that 10-year-old Jean comes home from school and tells her father that she got in a big fight at school. How do you think he would respond to her? Now, imagine that her twin brother, Jake, comes home and reports the same thing. I think you can imagine that the father’s response would be different in this case. Boys are more likely to be reinforced for being aggressive than are girls. Aggressive boys are often the most popular children in elementary schools (Rodkin, Farmer, Pearl, & Van Acker, 2000) because they can use their aggressiveness to gain and maintain social status. On the other hand, girls who successfully use nonphysical or relational aggression may also gain social benefits.
Eagly and her colleagues have proposed that gender differences in aggression stem primarily from social norms and expectations about the appropriate roles of men and women (Eagly, 1987; Eagly & Wood, 1991). Eagly notes that in many nations, women are expected to have more highly developed other-oriented attributes, such as friendliness and emotional expressivity, and that when women do aggress, they use aggression as a means of expressing anger and reducing stress. Men, on the other hand, are socialized to value more self-oriented attributes, such as independence and assertiveness, and they are more likely to use aggression to attain social or material rewards (Campbell, Muncer, & Gorman, 1993). One meta-analysis found that participants were more likely to indicate that men, rather than women, would and should engage in the most aggressive behaviors (Eagly & Steffen, 1986).