A new study suggests that during ovulation, when women are most fertile, they are attracted only to masculine men.
The study conducted by UCLA researchers analyzed several published and unpublished studies on women's mate preferences and how they evolve and change during their menstrual cycle.
The UCLA study's findings hint that ovulating women are leaning more towards mates who display sexy traits like a masculine body and facial features, as well as certain smells and dominant behavior. The desire for these masculine characteristics by women do not last all month, however, and are dominant only during her menstrual cycle.
"Women sometimes get a bad rap for being fickle, but the changes they experience are not arbitrary," said senior author Martie Haselton, a UCLA professor of psychology and communication studies, in a press release. "Women experience intricately patterned preference shifts even though they might not serve any function in the present."
While the study suggests that a majority of the women are attracted only to masculine men during their ovulation period, they do not necessarily see them as long-term mates. The change in attitude of a woman when she was ovulating was believed to be "small" to "medium." However, this change was "statistically significant" and was not perchance.
"On fertile days of the cycle women prefer the George Clooney type of guys, the sexy ones," says Haselton. "Whereas on the less fertile days of the cycle women prefer the partner that will be there for them potentially and help them care for their offspring, someone more stable."
The research by the study authors also considered scent studies. Women were asked to smell shirts worn by men "with varying degrees of body and facial symmetry." It was revealed that women preferred the smell of "more symmetrical men" during their menstrual cycle when they were ovulating.
Previous studies have shown that facial symmetry often determines the attractiveness of an individual. Moreover, deeper voices in men may be reflective of higher testosterone and masculinity, which women find attractive as well.
However, the current study was unable to highlight which specific masculine features were found to be most attractive.
According to the researchers, the shift in mate preference by women can be pinned to an "evolutionary adaption." Currently, several medical amenities are at hand, but this was not the case in the past when child and infant mortality rates were high. Moreover, sanitation and nutrition were also concerning factor. Therefore, as a result, female ancestors were likely attracted to physically stronger-looking men, fueled by the notion that the offspring would be strong and would survive.
"Ancestral women would have benefited reproductively from selecting partners with characteristics indicating that they'd be good co-parents, such as being kind, as well as characteristics indicating that they possessed high genetic quality such as having masculine faces and bodies," per Haselton. "Women could have had the best of both worlds -- securing paternal investment from a long-term mate and high-genetic quality from affair partners -- but only if those affairs were timed at a point of high fertility within the cycle, and probably only if their affairs remained undiscovered."
The study will be published in the Psychological Bulletin on February 24.