By Emma Young

Introduce a single man to a single woman and the odds are that he will over-estimate how sexually interested she is in him, while she will under-estimate his sexual interest in her. This sex difference in misperceptions has been found by researchers time and again. The conventional explanation is that these are evolved adaptions — that’s it’s more evolutionarily costly for a man to miss a chance to mate with an interested partner than it is for a woman, and more costly for a woman to engage in sex with an uncommitted man than vice versa. But now a new study, published in Psychological Science, challenges this notion, and provides some alternative explanations.

A team led by Anthony J Lee at the University of Stirling recruited 586 male and 640 female students for a set of speed-dating experiments, each of which typically involved three to four men and three to four women. All the participants identified as heterosexual and none were in a committed relationship. After rating their own attractiveness (using a measure that included personality as well as physical attractiveness), they embarked on a series of three-minute-long “dates” with each opposite-sex member of their group.

After each date, the participants rated their sexual interest in their partner and also their perceptions of their partner’s sexual interest in them. At the end of the session, they completed a questionnaire that assessed their “sociosexual orientation” — essentially, the extent to which they were willing to engage in uncommitted sex.

In total, the researchers gathered data on 3,850 interactions. Their analysis showed that both the men and women had some insight into their partners’ level of sexual interest in them. However, this was far from perfect, and, consistent with earlier studies, overall, the men over-perceived their partners’ interest, while the women under-perceived it.

Next, the researchers explored what might account for this sex difference. Two factors — both of which were linked more to the men than the women — stood out as being associated with over-perceptions of sexual interest. The first was having a short-term mating strategy (having a positive attitude towards uncommitted sex). The second was a participant’s own levels of sexual interest in their partner: the more interested they were, the more interested they thought the other person was in them. In these cases, it seems, the participants were projecting their own interest onto their date. And when the researchers accounted for these two factors in their analysis, the sex differences disappeared.

“Collectively, these findings suggest that the sex difference in misperceptions can be explained by a combination of a. men scoring higher than women on sociosexual orientation… and b. men being more interested in their partners,” the researchers write.

The first factor — being motivated to engage in uncommitted sex — might have been evolutionarily encouraged more in men than in women. However, statistically-speaking, the second factor was much more important in explaining the sex differences in misperceptions. And the researchers do not believe that projection of sexual interest is likely to be a specialised male adaptation for boosting their reproductive success. Perhaps, they suggest, it might rather reflect a tendency for individuals to assume that other people think the same way that they do. If this interpretation is right, then men seem to be more susceptible to this than women.

Overall, they conclude: “Previous theories for the purported sex differences in misperceptions of sexual interest emphasize that men and women have evolved different psychologies because of sex-specific selection pressures. Our findings challenge this popular notion.”

– Sex Differences in Misperceptions of Sexual Interest Can Be Explained by Sociosexual Orientation and Men Projecting Their Own Interest Onto Women

Emma Young (@EmmaELYoung) is a staff writer at BPS Research Digest