Roots of Prejudice Differ Among Men and Women New research suggests men develop prejudice against different groups because of aggression. Women, however, display prejudice because of fear.

Michigan State University researchers discovered that throughout the course of history, men have been the primary aggressors against different groups as well as the primary victims of group-based aggression and discrimination.

“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 Carlos David Navarrete, Ph.D., evolutionary psychologist at MSU.

This primordial behavior has been demonstrated in modern times among wars in Central Africa and the Balkans that were marred by rape and genocide, said Navarrete.

The research appears in Philosophical Transactions of the Royal Society B, a London-based research journal.

Investigators analyzed current academic literature on war and conflict and found that the standard social science theory did not explain the sex differences in aggressive or discriminatory behavior between groups.

Researchers offer a new theory that integrates psychology with ecology and evolutionary biology.

Their “male warrior hypothesis” explains how a deep evolutionary history of group conflict may have provided the backdrop for natural selection to shape the social psychologies and behaviors of men and women in fundamentally distinct ways.

The theory explains that men are more likely to start wars and to defend their own group, sometimes in very risky and self-sacrificial ways. Attacking other groups represents an opportunity to offset these costs by gaining access to mates, territory, resources and increased status.

The authors complement these findings with lab research that shows men are more prejudiced toward other groups.

The researchers explain women’s prejudice as resulting from a threat of continual sexual coercion by foreign aggressors. Women are apt to display a “tend-and-befriend response” toward members of their own group, while maintaining a fear of strangers in order to protect themselves and their offspring.

Researchers say that while evolutionary challenges fostered the prejudicial behavioral responses, the vestige is detrimental to current society.

“Although these sex-specific responses may have been adaptive in ancestral times,” said doctoral student and lead author Melissa McDonald, “they have likely lost this adaptive value in our modern society, and now act only to needlessly perpetuate discrimination and conflict among groups.

Navarrete added that the behavior is 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,” he said.

Since the behaviors are common among both humans and chimps, they are likely to have existed in our common ancestor millions of years ago, Navarrete said.

“This would have provided eons of time for the deepest workings of our minds to have been fundamentally shaped by these cruel realities,” he said.

“Coming to grips with this history and how it still affects us in modern times may be an important step into improving the problems caused by our darker predispositions.”

Source: Michigan State University