David A. Puts, an assistant professor of biological anthropology at Pennsylvania State University said many researchers have thought human sexual selection was based on a person's attractiveness.
The study, published in the Evolution and Human Behavior, found it appears physical competition among males was more important than physical attractiveness.
Traits indicate physical prowess was the major force in human mate competition -- men are far more aggressive than women and about 30 percent of men in small-scale foraging communities die violently, Puts says. Other male traits imply competition. Males have thicker jawbones, with fighting results in the thickest-boned men surviving. Competition among men may explain why males have more robust skulls and brow ridges than women.
Humans and chimpanzees create male coalitions to help defend females from other males, but when external threats are absent, these same males can compete with each other for mates, Puts says.
Puts says the findings are similar to the studies of mating in apes. In apes, male competition determines mate access with the winning male choosing the women of his dreams.