We marry those like ourselves.

• Position: Your Life - Brief Article

Given the reasons why people choose their mates, maybe men and women are from the same planet after all, says an evolutionary anthropologist from the University of California, Davis. In fact, when men and women are out shopping in the mate market, they actually are looking for people with traits that they rank highly within themselves, notes Monique Borgerhoff Mulder.

"We already know that men and women's preferences are relative: Individuals not only assess their own quality as a mate relative to that of their companions', but also form a mate preference based on their self perception."

Her research found that people want mates who reflect their own values. For instance, in a study of solicitations in singles columns, women who claim to be attractive and men who claim to...