In the study, researchers found beauty was a key factor for men, while choosier women would try to parlay their looks for security and commitment, the Bloomington, Ind., university said Tuesday in a news release.

This formula served humans throughout time, with the model of fussy females reflected in most mammals, said IU cognitive scientist Peter Todd and his coauthors. The study used a speed-dating session in Germany to compare what people say they want in a mate with the person actually chosen.

"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.

"Different cognitive processes underlie human mate choices and mate preferences" will be published the Sept. 4-7 issue of the Proceedings of the National Academy of Sciences.