This formula has served humans throughout time, with the model of choosy females reflected in most mammals, Todd and his coauthors write in "Different cognitive processes underlie human mate choices and mate preferences," which will be published the week of Sept. 4-7 in the Proceedings of the National Academy of Sciences.

"Evolutionary theories in psychology suggest that men and women should trade off different traits in each other, and when we look at the actual mate choices people make, this is what we find evidence for," Todd said. "Ancestral individuals who made their mate choices in this way -- women trading off their attractiveness for higher quality men and men looking for any attractive women who will accept them -- would have had an evolutionary advantage in greater numbers of successful offspring."

Not exactly politically correct? Participants in Todd's study might verbally agree, though their actions said something different.

The study used a speed-dating session in Germany to compare what people say they want in a mate with whom they actually choose. Speed dating, an increasingly popular way for singles to meet, involves sessions in which men and women have numerous "mini dates" with up to 30 different people, each date lasting anywhere from three to five minutes. After every date, the men and women checked a box on a card noting whether they would like to see the other person again. Todd and his colleagues describe such speed-dating events as a "microcosm where mate choices are made sequentially in a faster and more formalized fashion than in daily life."

For Todd's study, 46 adults in a speed-dating session were also asked to fill out a questionnaire beforehand assessing themselves and their ideal mate according to evolutionarily relevant traits, such as physical attractiveness, present and future financial status, health and parenting qualities.

Not surprisingly, Todd said, participants stated they wanted to find someone who was like themselves -- a socially acceptable answer. But once the sessions began, the men sought the more attractive women and the women were drawn to material wealth and security, setting their standards according to how attractive they viewed themselves. Furthermore, while men on average wanted to see every second woman again, the women wanted to meet only a third of the men again.

While the study's results came as no surprise to Todd, the research usefulness of the speed-dating forum did. Todd and his colleagues are conducting several other speed-dating studies that could confirm the results.

"Speed dating lets us look at a large number of mate choice decisions collected in a short amount of time," Todd said. "It only captures the initial stage of the extended process involved in long-term mate choice. But that initial expression of interest is crucial for launching everything else."

Source: Indiana University