Although it has long been a part of the popular imagination (who hasn't seen that obnoxious Meg Ryan scene, or one of the thirty-five episodes of "Sex and the City" devoted to the topic?), the fake orgasm has not received much systematic scientific study.
One problem with studying faking is that such a study relies on asking people about behavior they are not necessarily proud of. People don't like to admit they lie. Ask them if they lied, and odds are they will lie and say they haven't.
In 2009 researchers at the University of Kansas surveyed several hundred students about their experiences with--and reasons for--faking orgasms. About one quarter of males and one half of females admitted to faking. Faking for both sexes occurred most frequently during intercourse, and more often with steady partners than with one night stands; moreover, no correlation was found for either sex between ease of achieving orgasm and frequency of faking. In other words, those who faked did not do so because they were generally less orgasmic.
Why did those who faked do it? Reasons were quite similar across the sexes. Both faked mainly to end the session, having figured that real orgasm was not likely, or having had their interest or energy exhausted. But some important differences did emerge. When a man fakes an orgasm, sex is over. A woman fakes to signal to the man to come so sex can end.
How were orgasms faked? Both men and women relied largely on similar strategies, including vocalizations, changes in breathing, increased thrusting, and then stopping and feigning fatigue. But gender differences did emerge. Women relied significantly more than men on vocalizations to convey orgasm. This difference in the reliance on sexual sounds to convey sexual states may again relate to the genders' different physiology. As mentioned, male sexual arousal, excitement, and orgasm are signaled by rather clear external cues. You can touch and feel a man's erection, which signals arousal quite reliably. You can't fake an erection.
The finding that people fake orgasm does not constitute an earth shattering (ha!) discovery. Faking in general is a well known phenomenon within the social-interpersonal realm. We fake, lie, and deceive routinely in our day-to-day lives. However, when it comes to science, lies can reveal important information. When we lie, we often unwittingly expose our true expectations and the social scripts that undergird our behavior. If you fake an orgasm in order to achieve a certain goal--say the end of a sexual encounter--then we know that you and your partner have an expectation that orgasm means the end of sex.
Our movement in the world is scripted and organized like this even in areas we consider intimate and private, such as the bedroom. Like other scripts, your sexual arousal script integrates commonly-held social norms (high heels are sexy) with personal preferences picked up by your particular experience and temperament (if he bites the back of my left knee while at the same time caressing my elbow--I'm there).
Generally, then, the sexual encounter is as scripted as the restaurant trip. As much as your sex life seems wild, spontaneous, original and free-form to you, it is still directed and bounded by a subterranean system of rules and habits. The way you fake your orgasm allows scientists a glimpse into that system.
The evidence from the Kansas study suggests that the contemporary sexual script, at least for college students, dictates that the woman should reach orgasm first and then the man. This script may have consequences. For example, a woman who feels her man is about to come may be compelled to fake an orgasm so as to keep within the script, even if in doing so she gives up her opportunity to experience a real orgasm later.
On the other hand, another point that emerges from the findings is the notion that, according to script, the male has to be ready for sex and erect on command. A man who admits honestly that he's not interested in sex--right now or with you--may, by this script, jeopardize his masculinity. This part of the script may be the reason men often fake orgasm instead of admitting that they are tired, uninterested, or unable to sustain an erection.
As far as the ethics of sex go, the issue of faking orgasms raises interesting questions. Some claim that targeted faking, at certain times and in certain contexts, is appropriate, even commendable. The naked truth may be too painful if dumped on the head of someone who's not ready or equipped to hear it. A modest white lie may save much heartache, trouble and time. We all sometimes fake enjoyment ("Great cake! Really!" "Wonderful baby; I'm so happy you brought him with us to the restaurant and please keep talking about him;" etc) in order to grease the wheels of social commerce.
On the other hand, faking an orgasm in particular--like lying in general--is not without risks. All of us, after all, are susceptible to finding ourselves sliding down a slippery slope. One successful lie will easily lead to the next one, and the next one. Before you know it, you have a habit of lying. And as St. Augustine had said: "Habit, if not resisted, soon becomes necessity." A pile of lies, like piling debt, will in the long run weigh you down, not lift you up.
At the end of the day, it seems we can say with some confidence that relationships--sexual and otherwise--that are based on lies are likely to become disappointing and desolate compared to relationships based on truth, just as a fake orgasm is a disappointing and desolate experience compared to an actual orgasm.