Two apparently opposite evolutionary forces predispose males to warfare: a tendency on the one hand to violence and on the other to behave altruistically toward close kin. The evolutionary tendencies are then aggravated by cultural patterns of socialization that elevate “manliness” and the virtues of the warrior over gentler, more peaceable attributes. Centuries of warrior worship have continued to support aggressive evolutionary tendencies. Indeed, when enlightened thinkers began to praise peace and condemn the violence of war, men like Theodore Roosevelt and Henry Cabot Lodge expressed fear that the “race was becoming ‘over-civilized’ – too soft …the solution …would come from tapping into more primitive instincts, the kind brought out by sport, especially hunting and most of all by war.”

Evolutionary legacies

Evolutionary biology has shown persuasively that human beings are genetically closer to chimpanzees than to any other biological group, and observational studies have shown that both humans and chimpanzees exhibit a strong tendency toward violence. Richard Wrangham and Dale Peterson raise important questions on this tendency:

Biologists and anthropologists are uncovering more and more evidence on the connection between gender and violence in both humans and chimpanzees. The widespread violence among humans is largely male violence. In the United States, “men are almost eight times as likely as women to commit violent crime.” Can the gender difference be accounted for by the difference in size and strength between males and females? Available data on same-sex murders, where there is no gender-based advantage for the killer, yield a negative answer to the question:

The male tendency to violence is frighteningly real. Wrangham and Peterson note that at present “the remedies for male violence occupy the domain of politics, not biological philosophy,” but they also hold out hope that, since the tendency to violence is evolutionary, it can change over time. As I’ve suggested in the first two chapters, however, the problem may be cultural and psychological more than political, and twenty-first-century culture supports a psychology of violence in its very definition of masculinity.