Most of us remember the first time we heard about sex. Maybe it was during an elementary school introduction to the birds and the bees, or perhaps it was when we heard an older sibling whispering about it with some friends. Back then it seemed like something mysterious, a great big secret that someday we might share, too.

Fast forward 15 or 20 years, and here we are: wiser, cooler, and totally knowledgeable about the “S word”. Or not.

Turns out people are still confused about sex — specifically, how many people we’re supposed to do it with. New research suggests men and women consistently lie about how many people they’ve slept with, with men tending to overrepresent and women tending to underrepresent their number of sexual partners. That could be because (at least in Western society) there’s not a ton of frank or open discussion about sexuality. When it comes to having a “healthy” sex life, we’re all still guessing at what that means.

What’s the Deal?

In the new study, researchers led by Dr. Terri Fisher of Ohio State University recruited 293 college students between the ages of 18 and 25. They asked them to fill out a questionnaire rating how often they engaged in 124 different behaviors. In an earlier study, different participants had indicated which behaviors they thought were typical of males (e.g. telling obscene jokes) or females (e.g. writing poetry).

Here’s where the science got tricky: Some students filling out the questionnaire were hooked up to “lie detectors.” (The machines weren’t actually working, but students thought they were.) Turns out that for most of the activities, it didn’t matter whether people were attached to the lie detector — men were consistently more likely to report engaging in stereotypically male behaviors, while women were more likely to say they engaged in stereotypically female behaviors. Sex was the only area where the lie detector made people more honest. Men attached to the lie detector reported fewer partners than other men, while women attached to the lie detector reported more partners than other women.

Another study conducted by Fisher and colleagues in 2003 yielded similar findings about men and women’s willingness to fib about their sex livesTruth and consequences: using the bogus pipeline to examine sex differences in self-reported sexuality. Alexander, M.G., Fisher, T.D. Department of Psychology, University of Maine, Orono, ME, USA. Jounal of Sex Research 2003 Feb;40(1):27-35.. Back then, men and women attached to the fake lie detector reported about the same number of sexual partners. In the more recent study, women attached to the lie detector reported even more sexual partners than men attached to the lie detector.

Why It Matters

Researchers have known for a while that people’s answers to questions about their sex lives — especially about their number of sexual partners — are influenced by gender normsDiscrepancies between men and women in reporting number of sexual partners: a summary from four countries. Smith, T.W. National Opinion Research Center, University of Chicago, IL. Social Biology 1992 Fall-Winter;39(3-4):203-11.. Technically, men and women should be expected to report about the same number of sexual partners, though men consistently say they’ve had more bed buddies than women. Males between the ages of 30 and 44 self-report an average of six to eight female sexual partners in their lifetime, while women say they’ve had about four male partners (all of the participants identified as heterosexual).

Testing conditions in experiments make a difference, too: One study found men were more likely to report a greater number of sexual partners in the presence of a female experimenterSex of experimenter and social norm effects on reports of sexual behavior in young men and women. Fisher, T.D. Department of Psychology, The Ohio State University at Mansfield, Mansfield, OH. Archives of Sexual Behavior 2007 Feb;36(1):89-100. Some scientists think men are just trying to appear more macho and women more conservative, while other researchers say men and women just use different strategies to estimate their number of partnersCognitive strategies affecting recall of sexual behavior among high-risk men and women. Bogart, L.M., Walt, L.C., Pavlovic, J.D. et al. RAND Corporation, Santa Monica, CA. Health Psychology 2007 Nov;26(6):787-93..

All this research points to the realization that no one actually knows what it means to have a healthy sex life. It would seem like most people are dissatisfied with their sexual experiences, either because they think they’re too promiscuous or too prudish. That idea is reflected in the results of a survey from dating site, which found that both men and women are put off by potential partners who have already slept with more than 10 people (though they were also weirded out by those who have been with fewer than 10). That means there’s an extremely small margin for sexual history that’s considered socially appropriate.

Part of the problem may be that there is no one scientifically backed number of partners to indicate a healthy sex life. So we’re left to ask, or imagine, what our friends are doing behind closed doors and assume that, if our experience is different, it’s wrong in some capacity.

Of course, it’s possible to have fulfilling and unfulfilling sex lives with any number of partners. Unfortunately, there isn’t an easy way to make people accept this idea, short of holding sex ed courses in the places where we work and live as adults.

With any luck, this research will make people feel a little better about their own sex lives, and even more willing to talk honestly about them. In an ideal world, everyone would feel great about their sexual past. Until then, it’s nice to know we’re not the only one blushing during the walk of shame.