Sociobiology has ignored the results of psychology, which is the discipline between biology and society. Campbell's target article fills some of the gaps beautifully, but the fact that women's direct and physical aggression has increased during the past 20 years, undermines Campbell's evolutionary explanation of female aggression. The two classical types of theoretical explanations of aggression are that (1) aggression is a drive and (2) aggression is instrumental behavior. Expressive aggression, assumed to be typical of women, is no more drive aggression than is men's aggression.