Here's Why Men Are More Likely To Lie About How Many People They've Slept With

How do you keep track of sex partners past? Do you log each name in a tidy spreadsheet, complete with date and handy descriptors? Do you have a running list shoved in your bedside drawer? Do you make actual notches on your bedpost? Or did you never establish a system, and now rely on your brain to keep count in case anyone ever asks for your number? According to a new study out of the University of Glasgow in Scotland, the latter seems to be the case for many cisgender men — who, surprise surprise, may be erroneously generous with their sex partner estimates.

The study, published in the Journal of Sex Research, pulled data from the U.K.'s National Survey of Sexual Attitudes and Lifestyles. Men typically report more partners than cisgender women do — but, as the authors note, we should not see much of a difference between counts in a small, closed population. The men and women having sex with one another in those areas should have roughly equivalent sexual histories. But looking at figures from a sample of roughly 15,000 people ages 16 to 74, between 2010 and 2012, researchers noticed a trend: Men with female partners reported having slept with 14 people on average, whereas women with male partners reported an average of seven people.

When researchers removed the 99th percentile participants — i.e., cis men who said they'd had sex with 110 people, and cis women who clocked in at 50 — the gender gap narrowed further. Notably, men were more likely to omit oral sex partners from their totals than were women, although they received it more often than women did. (Again, not shocking: There is data on this topic, too.) The men in the sample were also more likely to ballpark their numbers, whereas women kept count.

Kirstin Mitchell, a senior research fellow at the university's Institute of Health & Wellbeing and the study's lead author, tells Bustle that this particular gender gap "has been narrowing over the years, thanks to improved survey methods and more relaxed attitudes to sex."

Further, she adds, it is "important to note that over shorter time periods, the gender gap is actually very small." But even as we move toward more equitable (and/or realistic) reports, we should not write off the trend as just another instance of predictable-if-harmless dudely ego stroking: When it comes to gauging the prevalence of sexually transmitted infections (STIs) and how we swap them back and forth, Mitchell emphasizes, accuracy matters.

The study's authors point to three possible culprits: Anomalies in the sample — including the underrepresentation of sex workers (the survey asks participants if they've paid for sex, but not if they've been paid); the wide range of age groups polled; and the possibility that some people accrued new sex partners when they travelled abroad — may skew the numbers. Or, a "male tendency to approximate," as the authors write, may mean they generate higher estimates, while a "female tendency to enumerate" means lower, if also more accurate, tallies. Or, social expectations and pressures prompt women to lowball their own counts, and men to inflate them.

"I think both men and women want to be seen in a good light and so they consciously or unconsciously attempt to conform to what they perceive as acceptable for their gender," Mitchell says. "Although attitudes towards sex have relaxed over the years, women continue to be more conservative in their attitudes towards non-exclusive and casual sex, and these gender stereotypes (men as sexually active; women as sexually chaste) still persist."

While they don't know why men seem more inclined to estimate than do women, Mitchell says the top one percent of guys who reported "extreme numbers" may indicate that "the pressure to conform is felt more keenly by men." But regardless, it would seem that anticipation of judgment — either for not living up to the sexual prowess society vaunts in one gender, or the modesty it imposes on another — leads us to fudge the numbers.