Men, Honor and Murder; Men: The Scientific Truth; Scientific American Presents; by Nisbett, Cohen; 4 Page(s)

Homicide overwhelmingly involves males-as both perpetrators and victims. Evolutionary psychologists Martin Daly and Margo Wilson estimate that across a wide range of cultures a man is more than 20 times more likely to kill another man than a woman is to kill another woman, a finding they explain by arguing that men are more risk prone than women [see "Darwinism and the Roots of Machismo," on page 8]. Moreover, men are more likely to kill women than the other way around. When a woman does commit homicide, she usually kills a man who has repeatedly physically abused her.

These facts, together with the observation that males are the more aggressive sex in nearly all mammals, have led many people to suppose that men are unavoidably aggressive and that homicide is a natural consequence of male biology. Yet the striking variation in homicide rates among different societies makes it clear that, whatever men's predispositions may be, cultures have a great influence on the likelihood that a man will kill. For example, Colombia's rate is 15 times that of Costa Rica, and the U.S. rate is 10 times that of Norway. Marked regional differences exist even within the U.S. We and our colleague Andrew Reaves have established that in small U.S. cities in the South and the Southwest, the homicide rate for white males is about double that in the rest of the country. We also found that a white man living in a small county in the South is four times more likely to kill than one living in a small county in the Midwest. By making detailed regional comparisons, we have been able to rule out several explanations that have previously been offered to account for similar data, such as the history of slavery in the South, the higher temperatures there and the greater incidence of poverty.