Remember the Katz’s Deli scene in “When Harry Met Sally” when Sally (Meg Ryan) writhes and moans and pounds on the table to demonstrate her pitch-perfect imitation of la petite mort?

“Most women at one time or another have faked it,” she says.

“Well, they haven’t faked it with me,” Harry (Billy Crystal) retorts.

Sally’s right. Sixty-seven percent of heterosexual women admitted to occasionally faking orgasm in a study published last year in the Journal of Sex Research (Vol. 47, No. 6). And like Harry, most men don’t believe it could happen to them, with only 20 percent saying they think their female partners might fake, according to another yet-to-be published study by William McKibbin, PhD, a psychology professor at the University of Michigan, Flint.

“The men also reported they’d be distressed to find out their partners were faking,” says McKibbin.

With 28 percent of men occasionally faking it themselves, they shouldn’t be too surprised. What is surprising: Faking isn’t always bad for your sex life. Depending on a woman’s motivation, pretending to orgasm can actually increase her sexual satisfaction, according to research by Erin B. Cooper, a clinical psychology doctoral student at Temple University.

“Some women may fake it ’til they make it,” says Cooper, who presented her research at APA’s 2010 Annual Convention in San Diego.

Cooper and McKibbin are among a growing number of scientists studying the human orgasm, a topic frequently covered by women’s magazines but relatively unexplored by the research community. In the past few years, however, scientists have conducted a slew of studies and written several books on the topic — with the function of female orgasms emerging as a particularly hot area of debate.

While this research may not lead to a cure for cancer, it isn’t frivolous. Orgasms are, after all, a major motivating factor behind many human behaviors, and they play a crucial role in the story of our species’ evolution, Cooper says.

“We can’t leave it to pop culture and movies to explain these things,” says Cooper. “Sexuality is such an important part of people’s lives.”

‘Fantastic bonus’ or fertility control?

Like Harry, 90 percent of men say they care if their partners have orgasms, and there may be a deeply rooted reason for that, according to a study by McKibbin, published in Personality and Individual Differences (Vol. 49, No. 8).

McKibbin and his colleagues surveyed 299 heterosexual men in committed relationships, asking how much time they had spent with their partners since they last had sex. The men also revealed how much they wanted their partners to climax the next time they had sex, and how hard they’d work to make it happen. The study found that the men most interested in their partners’ future orgasm were the ones who hadn’t seen much of their girlfriends or wives lately.

But why reward potential infidelity with orgasms?

“Our research gives some preliminary evidence supporting the idea that the female orgasm functions to selectively uptake a particular man’s sperm over another,” McKibbin says.

Humans probably evolved in societies in which it was common for a woman to sleep with many men over a relatively short period of time, argues biologist Alan S. Dixson, PhD, in his book, “Sexual Selection and the Origin of Human Mating Systems” (Oxford University Press, 2009). That’s why men have relatively large testicles and produce so many sperm, Dixson posits. Male mountain gorillas, in comparison, face a low risk of sperm competition because they keep close watch over a harem of females, possibly explaining their relatively small testicles.

While there’s solid evidence for sperm competition, there’s less grounding for the theory that women’s orgasms have anything to do with fertilization, says Elisabeth Lloyd, PhD, a science historian at Indiana University, Bloomington, and author of “The Case of the Female Orgasm: Bias in the Science of Evolution” (Harvard University Press, 2005). The current evidence, she says, suggests the female orgasm is simply a byproduct of the male orgasm.

“The female orgasm is like the male nipple. It has a clear function in one sex, but not in the other,” she says.

The male orgasm positively reinforces ejaculation and therefore encourages males to propagate the species, Lloyd says. Women get a parallel ability as a “fantastic bonus” because their tissues and nerves are laid down at the same time during fetal development.

In support of the fantastic bonus theory, Lloyd points out that only about 8 percent of women reliably have otherwise unassisted orgasms during penile-vaginal intercourse, while nearly all men do. In addition, these women seem to be benefiting from an accident of physiology — they happen to have clitorises that are close to their vaginal opening, according to new research by Lloyd and Emory University psychology professor Kim Wallen, PhD, in press in Hormones and Behavior.

“Very few women can climax through intercourse alone, but in Hollywood, that 8 percent [of women] is portrayed as 100 percent,” she says. “It’s like, in some misguided bid for equality, we are trying to make women’s orgasms serve the same function as men’s.”

Though scientists have yet to make a direct link between orgasms and fertility, there’s a growing body of research pointing in that direction, counters Barry Komisaruk, PhD, an orgasm researcher and psychology professor at Rutgers University. For example, researchers at the University of Manchester found fewer sperm in the post-coital “flowback” of women who had orgasms versus those who didn’t (Animal Behaviour, Vol. 46, No. 1.) Another research team, at the Universities of Erlangen and Gottingen, Germany, found through a series of studies that uterine contractions are the primary method of sperm transportation. These contractions move sperm not only into the uterus, but laterally, toward the more mature ovarian follicle, and women who are better at doing this are more likely to get pregnant, according to a study published in Animal Behaviour (Vol. 4, No. 4). Pair that with research showing that uterine contractions intensify during the oxytocin release triggered by orgasm, and you have compelling evidence that the female orgasm, while certainly not necessary, can play a role in fertilization, says Komisaruk.

“Orgasm is a very complex function that involves the whole autonomic system and a huge amount of brain activity,” he says. “It must be doing something, and it’s up to us to figure out what that is.”

One possibility: Orgasms may allow women to make a subconscious last-minute call about whether they want to be fertilized by a particular partner. Supporting that idea is a study by researchers at the University of New Mexico, published in Animal Behavior (Vol. 50, No. 6). It surveyed 86 heterosexual couples and found women have more orgasms with men whose bodies are more symmetrical. For animals in many species, symmetry serves as shorthand for genetic quality — asymmetry suggests that an organism has developed abnormally. So these women are, perhaps, having orgasms to increase the chances of getting fertilized by genetically robust males, says the study’s lead author, Randy Thornhill, PhD.

The finding lends support to the idea that women could fake orgasms to reassure or trick their partners about paternity, adds McKibbin. It could also serve to reassure partners that they are, genetically speaking, high-quality males. That certainly jibes with his study, which found that men care more about their partners’ climaxing if they haven’t been together recently.

“It’s almost like an arms race, with women maybe evolving the orgasm to select high-quality sperm, men counter-evolving an interest in orgasms to help ensure paternity, and women perhaps evolving the tendency to fake, obscuring paternity,” he says.

Fish fake it, too

As with women, orgasm may give female fish the ability to make a last-minute call about their partners’ genetic quality. In a study published in Animal Behaviour (Vol. 61, No. 2), Swedish researchers recorded the spawning behavior of brown trout.

Brown trout reproduce externally — the male and female fish climax simultaneously and release their sperm and eggs into the open water. The event must be timed perfectly, so the female trout indicates she is about to release her eggs by digging a bed in the sand, crouching by it, opening her mouth and quivering. Male fish respond by crouching and quivering beside her. Their quivering intensifies and, about half the time, they both climax. The other half the time, the female quivers, but never releases her eggs.

That faking might serve the purpose of allowing female trout to save their eggs for higher-quality males, a theory supported by the observation that female trout were more likely to fake orgasms when better-looking, more dominant fish lurked nearby. More often, however, the females faked it when the males were not in the exact right position, says study author Erik Petersson, PhD, a biology professor at Uppsala University.

“What is the point of choosing a high quality male if you behave in such a way that your eggs will not be fertilized?” he says.

Perhaps for both women and fish, fake orgasms are an unconscious fertility-related adaptation, he adds.

As for heterosexual women’s conscious motivations, the most common reason women fake is “altruistic deceit” — or sparing their partner’s feelings, according to Cooper’s survey of 1,500 women. She also found that while altruistic fakers miss the opportunity to tell their partners what would make them climax, such faking doesn’t seem to affect their sexual satisfaction.

“I think of it as a relationship maintenance strategy,” she says, adding that women may fake orgasm to avoid difficult or uncomfortable discussions with their partners.

Less commonly, women fake orgasm to avoid having difficult discussions with themselves, Cooper found. These women feel that something is wrong with them if they don’t climax through intercourse, so they fake it to avoid facing their own fears. Such motivation, which Cooper terms “insecure avoidance” predicts less sexual satisfaction.

Some women, found Cooper, may be able to actually increase their sexual satisfaction by faking orgasm. These women fake for their own enjoyment, and report heightened levels of arousal as a result.

In any of these cases, the root reason women pretend to have orgasms is to shore up the difference between expectations and reality, according to University of Kansas psychology professor Charlene Muehlenhard, PhD.

A study she and student Sheena Shippee conducted, published in 2010 in the Journal of Sex Research (Vol. 47, No. 6), found that most faking happened during penile-vaginal intercourse. Of the women who had ever feigned orgasm, 55 percent pretended in that scenario, as compared with just 8 percent during oral sex and 4 percent during manual stimulation.

This finding supports the idea that there’s a cultural script at play, where women and their partners expect them to orgasm without external clitoral stimulation, Muehlenhard says. When expectations and reality don’t line up, people fake it — men and women.

“When men pretended orgasm, it was often because they saw no other way for sex to end,” she says. In response to the question about what would have happened had he not pretended, one man wrote, “I would probably be going to this day!”

Taken together, the research suggests that many heterosexual couples share relatively rigid beliefs about the way sex should go — with a period of foreplay, followed by the woman peaking, then the man. That’s too bad, says Lloyd, since it prevents couples from exploring their limitless potential for sexual expression.

“Sexuality is a wonderfully complex thing,” she says. “We shouldn’t be so focused on getting to the finish line.”

Further reading

  • Dixson, A.F. (2009) Sexual Selection and the Origins of Human Mating Systems. Oxford: Oxford University Press.

  • Komisaruk, B.R., Beyer-Flores, C. & Whipple, B. (2006) The Science of Orgasm. Baltimore: The Johns Hopkins University Press.

  • Lloyd, E.F. (2005) The Case of the Female Orgasm: Bias in the Science of Evolution. Cambridge, Mass.: Harvard University Press.