This article has been updated to note a change.
Ovulating women prefer men with masculine characteristics compared to traits they look for in long-term mates during any other time.
Martie Haselton, a professor of psychology and communication studies at the University of California, Los Angeles and the report's senior author, defends this female behavior.
"Women sometimes get a bad rap for being fickle, but the changes they experience are not arbitrary," she said in a statement.
The controversy over whether high fertility in women determines her mate preferences has long been debated, and so Haselton and her colleague Kelly Gildersleeve pooled past research data from 50 studies and made them compatible with each other so the findings could be better analyzed. What they found was that women's preference shift during ovulation proved to be statistically significant.
Haselton went further to determine which specific male characteristics trigger a stronger reaction in ovulating women. She looked at body scents specifically, asking women to smell T-shirts that men with varying degrees of body and facial symmetry wore. Women favored the odor of more symmetrical men when in high fertility states, but Haselton says more evidence is needed to make these results conclusive.
Another one of her studies showed that women who are partnered to men they think are less sexy are more likely to be attracted to other men during ovulation than women who rate their male partners as very sexy.
Gildersleeve hypothesizes that male preference is an evolutionary adaptation to help women survive.
"Under this hypothesis, women who preferred these characteristics were more likely to pass on beneficial genetic qualities to their children, thereby enhancing their children's chances of survival and reproductive success," she alleged in the same statement release.
In a past study, Haselton proposed a "dual mating hypothesis": ancestral women would approve of resourceful men displaying kindness and reliability (traits of a father figure) and masculine, sexy men. This method for choosing a partner would benefit women in terms of reproduction, she adds.
No matter the root influence, these researchers believe that, like in all cases, knowledge is power.
"If women understand the logic behind these shifts, it might better inform their sexual decision-making so that if they notice suddenly that they're attracted to the guy in the next cubicle at work, it doesn't necessarily mean that they don't have a great long-term partner," Haselton said. "They're just experiencing a fleeting echo from the past."
