Strangers influence our dating preferences

"Humans don't exist in a vacuum. From an evolutionary standpoint, it makes sense that we have evolved mechanisms that let us take advantage of the additional social information in our environment," said Skyler Place, a researcher in IU's Department of Psychological and Brain Sciences and lead author of the study along with Peter M. Todd, professor in IU's Cognitive Science Program.

"We might think that searching for mates is a process best done individually, that we can best gather the appropriate information by ourselves," Place said. But humans, like many other animals, also pay attention to the preferences of others, to make for a more efficient search process. Who others like might also be a good choice for ourselves."

The concept of "mate choice copying," where an individual copies the mate selections of others, has been widely documented in other species, particularly birds and fish, and has recently been looked for in humans as well. Place's study, published online and in an upcoming issue of the journal Evolution and Human Behavior, is unique in that it exposed study participants to real mate choice scenarios via video of speed-dating couplings.

For the current study, 40 men and 40 women each watched video of eight speed-dating interactions. Speed dating involves sessions in which men and women have numerous "mini dates," each date lasting about three 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. Place and Todd describe such speed-dating events as a realistic microcosm of mate choice behavior.

The study participants were IU students and the speed-dating was conducted in Germany. The students were asked to predict whether they thought the dates were successful as part of the study. The researchers then looked at how the participants own desires to become romantically involved with the individuals going speed-dating changed based on what the participants thought happened on the speed-dates.

The men's interest in the women generally increased after watching the videos but it increased significantly more if their male peer in the video appeared to be interested in the women and if the men were considered as attractive or more so than the study participant.

With the female study participants, their interest in the men in the video increased if their peers in the video appeared interested; but unlike their male counterparts, their interest in the men decreased if the women in the video appeared uninterested. Place said interest shown by the men and women was no different when they were asked whether they were interested in a short affair or long-term relationship.

An intriguing finding involved the sway men had on each other. Place found that the interest of his male study participants in the women in the videos increased in relation to the good looks of the men in the video.

"For men, relative attractiveness of the people they're watching matters -- not just anyone can influence their behavior, just other men they think are at least as attractive as they are," Place said. "We have also seen signs of this influence for women in a larger study still being analyzed."

Place said the influence of strangers is also an important addition to mate choice research.

"Of course people care about what friends and family think of their potential romantic partners. Surprisingly, we showed that complete strangers also matter," he said. "If you walk into a party and don't know anyone, you might think, 'Why do I care what anyone here thinks?' In reality, we're paying close attention to what others in our social environment are thinking and doing."

Co-authors include Peter M. Todd, IU Cognitive Science Program; Lars Penke, Centre for Cognitive Ageing and Cognitive Epidemiology and the Department of Psychology, University of Edinburgh, U.K.; and Jens B. Asendorpf, Department of Psychology, Humboldt University of Berlin, Germany.