A commonly touted theory about how women's attraction to men works might be all wrong, suggests a new paper published this week in Psychological Science. Prior, small experiments have found that birth control pills and ovulation could change a woman's sexual preferences. Now, a large new study has found that women's preferences for men's faces are reliably stable, regardless of whether they're taking birth control pills or whether they're ovulating.
Women who are attracted to men tend to prefer the more traditionally masculine face on the left, but that preference has nothing to do with whether or not they take the birth control pill, a new study finds. Illustration: Jones, et al. (Psychological Science)
Some previous experiments have found that women taking hormonal contraceptives or experiencing their period were more likely to favour male facial features that are less associated with testosterone, like a rounder jaw or thinner eyebrows. But these studies may have been flawed from the get-go, according to Ben Jones, a professor at the University of Glasgow's Institute of Neuroscience and Psychology in the UK and lead author of the new work.
"Researchers have highlighted some potential methodological problems with these studies, like testing only a relatively small number of women," he told Gizmodo via email. "We set out to address these criticisms by carrying out the largest study of these issues to date."
Jones and his team recruited over 500 heterosexual-identifying women in the UK for their study. The women were shown 10 pairs of randomly selected male faces at the same time and told to pick which one they were more attracted to, as well as to rate how attractive the face was.
The faces were slightly digitally altered to be more masculine- or feminine-looking; i.e., their cheekbones might have become more or less prominent. And each testing session was broken down into two parts, taken separately: The women rated the faces in terms of either liking them for a short-term fling or for a committed relationship.
The women took these tests every week for five weeks, then were asked to come back in about six months and then about two years for more rounds of testing. At each session, they also submitted saliva samples, which were used to track hormone levels. The majority of women completed all five weeks of the first round, though only 200 returned for the second round six months later and only 18 returned for the third round two years later.
"We found no evidence that women's face preferences tracked changes in hormone levels or changes in women's use of oral contraceptives," Jones said. "Instead, we found that women generally preferred masculine men regardless of their own hormonal status."
The study has its own limitations. For one, all of the women who participated were white, and all of the digital faces were white as well. And of course, this was a highly controlled experiment involving digitally altered faces in a lab — how applicable such research might be to partner selection in the real world is up for debate.
Though it's just one study, Jones noted, it follows a paper published this past March that similarly found that for the women they studied, their menstrual cycle had no influence on how attracted they were to a man's body overall.
"I think the key thing for future studies on this topic is for researchers to be more ambitious in the scale and scope of the studies and to not be afraid to go back and test accepted results," Jones said. "I also think it's very encouraging that scientific journals are becoming more willing to publish these sorts of null results and not just be open to publishing results that confirm what we think we know."
Similar to other research, though, they found that women contemplating a fling picked more masculine faces on average, while women thinking about someone's long-term prospects picked slightly less masculine faces on average.
Ultimately, Jones and his team hope their findings can ease concerns that women taking birth control might have about the drug's effects.
"There are lots of reasons why women may want to or may not want to use hormonal contraceptives," he said. "Our research suggests that their possible effects on attraction shouldn't carry a lot of weight in those decisions."