Photo: Christophe Gateau/DPA/PA Images

One of the most striking misperceptions around is held by British men, who think that women aged between 18 and 29 have sex 22 times a month on average. The reality is a more mundane (or less ridiculous) five times a month. In fact, everyone guesses that everyone else is having more sex than they are. Women in Britain think young men are having sex 14 times a month, when the average is also around five.

But the gap between perception and reality is widest when it comes to male views of women. Men aren’t nearly so wrong about other men, and women aren’t so wrong about either gender. The trend is not confined to Britain: there is a near-identical pattern in the US.

The overblown view of women’s sexual activity is most extreme when it’s not only about young women, but when the male respondents are also young. The average guess among men aged 34 and under is that young women are having sex 33 times a month, more than once a day, while the guess of older men is “just” 14.

So, young men have an issue with how they see women’s sexual activity. All the women I’ve talked to about this give me a pitying, “well, that’s not news” look. But how can young men get it so wrong?

The likely explanations are what we’re told by the wider culture, as well as the biases and tricks our brains play on us. Vast overestimates are likely due to twisted ideas drawn from the representation of women in porn, the media and culture. All combined with fragile male egos, which assume women are having “all the sex.”