(RxWiki News) Men and women often exhibit different types of traits when it comes to aggression, prejudice and fear. Social science doesn't fully explain the gender differences, but perhaps evolution does.
Preference for our own social group is a common human trait, and an evolutionary strategy that was necessary for survival for thousands of years. But this bias against groups outside of our own appears to manifest differently in men and women.
Prejudice is linked to aggression in men, and fear in women, suggests new research from Michigan State University (MSU).
"Seek the help of a therapist if dealing with anger issues."
Carlos David Navarrete, an evolutionary psychologist at MSU, led research that analyzed academic literature on war and conflict. He was looking for a social science theory that explained the sex differences in aggression and discrimination.
Along with MSU researcher Melissa McDonald and Mark Van Vugt of the University of Amsterdam and the University of Oxford, Navarrete failed to find such a link. Instead, the three co-authored a study that offers a novel approach to such gender differences: evolutionary psychology.
"There is evidence going back thousands of years of bands of men getting together and attacking other bands of men, eliminating them and keeping the women as the spoils of war," said Navarrete.
Calling their theory the "male warrior hypothesis," the researchers explain that a deep evolutionary history of group conflict may have shaped the psychology and behavior of men and women in fundamentally distinct ways.
It could be the reason why men are more likely to start wars and act aggressively against those outside their group. Women, meanwhile, display more of a fear of strangers and a befriending mentality against those outside their group.
The authors cite results from lab experiments, showing that men are more prejudiced toward other groups, as support for their theory. Such distinct gender behaviors are also seen in humans' closest relative, the chimpanzee.
"Just like humans, they'll attack and kill the males of other groups. They'll also attack females - not to the point of killing them, but more to get them to join their group," Navarrete said.
The research appears in the January 2012 issue of Philosophical Transactions of the Royal Society B.