Link Between Ovulation, Ability to Identify Heterosexual MenWhen a woman is at peak ovulation, she can better identify whether a man is heterosexual or not by looking at his face, says a new study by psychologists at the University of Toronto and Tufts University.

Furthermore, harboring romantic notions or a mating goal increases a woman’s sensitivity in discriminating between straight and gay men.

“This effect is not apparent when a woman is judging another female’s orientation,” said Nicholas Rule, Ph.D., lead author of a new study published in Psychological Science. “This suggests that fertility influences a heterosexual woman’s attention to potential mates rather than merely increasing sensitivity to sexual orientation or nonverbal cues more generally.”

In the first of three experiments, 40 undergraduate females were asked to view 80 photos of men’s faces and judge each man’s sexual orientation; 40 of these were self-reported gay males, while the other 40 were straight men. The men did not differ in attractiveness or emotional expression and the women were encouraged to use their intuition in making decisions.

The women also reported how much time had passed since their last menstrual cycle and its average duration; none of the women were taking any systemic contraceptive medications.

The researchers compared the women’s accuracy in judging sexual orientation with the point at which the women were in their fertility cycle, and found that the closer a woman was to peak ovulation, the more accurate she was at judging a man’s sexual orientation.

In the second experiment, 34 women viewed a similar series of female faces, 100 of whom were self-identified lesbians while another 100 were straight. Interestingly, there was no relationship between the fertility cycle and accurate judgments of the women’s sexual orientation.

“Together, these findings suggest that women’s accuracy may vary across the fertility cycle because men’s sexual orientation is relevant to conception and thus of greater importance as women are nearer to ovulation,” Rule said.

This hypothesis was tested further during a third experiment in which the women were primed with a mating goal in order to manipulate reproductive relevance. Half of the volunteers were asked to read a story that described a romantic encounter while the other half did not, before judging sexual orientation through photos.  Researchers found that the women primed with a mating goal were far more accurate in their judgments than those who were not, suggesting that inducing mating-related thoughts improved accuracy in judging men’s sexual orientations.

Source:  University of Toronto