Near Ovulation, Your Cheatin' Heart Will Tell on You, Find UCLA, University of New Mexico Researchers


Date: January 4, 2006
Contact: Meg Sullivan ( msullivan@support.ucla.edu )
Phone: 310-825-1046

Higgamous hoggamous, woman's monogamous; hoggamous higgamous, men are polygamous. Or maybe not.

New research from UCLA and the University of New Mexico suggests that members of "the gentler sex" may have evolved to cheat on their mates during the most fertile part of their cycle — but only when those mates are less sexually attractive than other men.

"Women know they have attractions that come and go, but they probably don't realize that these urges are tied to their cycle — as well as our evolutionary past," said Martie G. Haselton, a UCLA researcher and author of two new studies on the subject. "They just know that suddenly one day they're attracted to their hunky neighbor or handsome co-worker."

Men, meanwhile, seem to be aware on some level of this possibility and appear to step up mate-guarding strategies when their wives or girlfriends ovulate, even when neither is keeping track of the woman's cycle, the research shows.

"It's not just that men are more jealous and possessive when their partners ovulate, but they're also more attentive to their partners and more giving to their needs," said collaborator Steven W. Gangestad, a University of New Mexico psychologist.

"Although men are probably not aware of it, they behave as though they're genuinely concerned about being cuckolded," Gangestad continued. "It turns out that there's some basis for the fear."

The findings advance recent research by Gangestad that has suggested a proclivity toward infidelity during ovulation. The new research, generated in collaboration with UCLA's Center on Behavior, Evolution, and Culture, pinpoints women who may be at greatest risk. The findings also suggest an evolutionary explanation for the so-called "adaptation."

For the first study, which will be reported in the Jan. 4 scholarly journal "Hormones and Behavior," Haselton, an assistant professor of communication studies and psychology at UCLA, and Gangestad recruited 38 female coeds from a large U.S. university. (The researchers are declining to name the institution so that the subjects don't find themselves in the position of being grilled by mates who learn of the sensitive findings.)

The subjects were asked to reveal information from which their date of ovulation could be deduced. Then they were asked to rate their partner's sexual attractiveness as measured by his desirability for a fling as well as his suitability as a long-term mate, on the theory that the first would reveal his sexual attractiveness while the second would reveal his abilities as a provider or potential provider.

Finally, the subjects submitted 35 diary-like entries, rating the strength of their attractions that day to men other than their mates and the frequency and manner with which they flirted or otherwise acted out those attractions. Also on a daily basis, the co-eds rated their own sexual attractiveness, sexual desires and sense of power within their romantic relationships.

Analyzing the diaries, Haselton and Gangestad found that ovulating had a strong effect on all women. Regardless of where they stood on other measures, the co-eds felt more desirable, attractive and powerful in their relationships during the mid-point of their cycle. But women who rated their mates as more suitable for long-term involvement than a quick fling had different behavior and desires than women who considered their mates hot.

"When women were mated to men with low sexual versus investment attractiveness, they were particularly likely to experience increased attraction to men other than their partners at mid?cycle," Haselton said.

The mates of these women, meanwhile, appeared to appreciate unconsciously what they were up against. Their wives and girlfriends reported many more acts of mate-guarding behavior than women who considered their mates to be fling-worthy.

"What is at stake is not just the loss of face or the loss of love," Haselton said. "This is about Darwinian prosperity. Males who did not successfully guard their mates are not our ancestors."

Only one group of men diverged from this pattern: They were the ones whose wives and girlfriends were the most physically attractive.

(more)