Women who don't trust their partner to stay faithful are more likely to fake orgasm, new research finds.

Women who are unsure of their partner's fidelity are the most likely to fake orgasms, as well as engage in other behaviors designed to hang on to their man, a new study finds.

The research is the first to quantitatively link suspicions of infidelity to the likelihood of faking orgasm, said study researcher Farnaz Kaighobadi, a postdoctoral researcher at the HIV Center for Clinical and Behavioral Studies at Columbia University.

But suspicion of infidelity isn't the only reason women might pretend they're having an orgasm, Kaighobadi said.

"A lot of the time, women are using it just as a tool to strengthen their relationship," she told LiveScience. "Sometimes women could be pretending orgasm just to show love and care to their partner."

The study was based on surveys of women, most of them in college and all of them heterosexual.

Cheating hearts and faked orgasms

Research on the female orgasm is relatively rare, Kaighobadi said. Previous studies used open-ended questions about women's sexual behavior, she said, and about half of the respondents said they had faked orgasm at some point in their lives. (By comparison, about 25 percent of men reported faking an orgasm.)

"One particular reason that emerges from a lot of studies is 'to keep my partner interested in this relationship,' or 'to prevent him from defecting [from] the relationship or leaving the relationship for another woman,'" Kaighobadi said.

To see if those anecdotes had a widespread basis, Kaighobadi distributed surveys to 453 women, ranging in age from 18 to 46, who had been in relationships for at least six months. Most of the women were Florida college students in their early 20s.

The surveys collected information about the women's demographics, their relationship dynamics and their sexual behaviors, including whether they had ever faked an orgasm during their current relationship. The women also were asked whether their partners had ever cheated, and how likely their partners were to do so in the future.

Adaptive orgasms

About 54 percent of the women in the study reported they had faked an orgasm at some point in their relationship. This group also was found to harbor more suspicions about their partners' fidelity than were the women who said they hadn't faked any orgasms.

Kaighobadi said these women also were more likely to engage in what psychologists call "mate-guarding" behaviors. Such behaviors can range from simply dressing up nicely for one's partner to keeping tabs of where he goes and telling off other women who look at him.

"It seems that women who were more likely to pretend orgasm were also more likely to do a variety of these behaviors at the same time," Kaighobadi said.

The researchers didn't ask how satisfied the women were with their sexual relationships, Kaighobadi said, so it was unknown whether faking orgasm is related to lower levels of satisfaction in bed. [Why Women Shrug Off Lousy Sex]

The research, published in the November issue of the journal Archives of Sexual Behavior, could help inform an academic debate about whether the female orgasm is adaptive, meaning it somehow gives women an evolutionary advantage, Kaighobadi said. Researchers have argued over whether orgasms help a woman retain sperm from valued partners, and whether having orgasms keeps a male partner interested — both of which would be considered adaptive functions.

"Only one or two studies provide evidence of whether there is an adaptive function or not," Kaighobadi said. "We're not sure, and I think there should be a lot more study."

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