Fact: Americans are sexually repressed, Europeans are not. So does that make American women especially sensitive about one night stands compared to their more sexually liberated female counterparts?

Researchers tackled this very question by studying one night stand habits and their resulting emotions in Norway, a country they describe as “more sexually liberated and egalitarian” than America.

The surprising results showed that women, on average, regret one night stands more often than men, and that men regret saying no to one night stands more often than women. Sexual liberation didn’t move the needle, and neither did the fact that these women were in liberal Scandinavia.

In a paper published in the journal Evolutionary Psychology, the team of American and Norwegian researchers studied 263 participants between the ages of 19 and 37 years old. Of that group, 35 percent of women and 20 percent of men reported feelings of regret the last time they had casual sex. In contrast, 30 percent of Norwegian women and 50 percent of men were happy about their most recent time having sex. The rest were meh about their one night stands.

The researchers believed the most compelling reasons for this gender divide are biologically driven between men and women. Evolutionary psychology dictates that reproductive success for men requires them to have as much sex as possible. But women are wracked by subconscious worries of pregnancy with a partner they don’t want around their entire life.

“Female choice — deciding when, where, and with whom to have sex — is perhaps the most fundamental principle of women’s sexual psychology,” study co-author David Buss said in a statement. “A key limitation on men’s reproductive success, historically, has been sexual access to fertile women. These evolutionary selection pressures have created a male sexual mind that is attentive to sexual opportunities.”

If it was great for him, it doesn't mean it was great for her.

However, while the researchers claim this doesn’t explain the overall gendered difference for regret after a one night stand, there’s a big elephant in the room: sexual satisfaction. Men orgasmed during casual sex at much higher rates than women; women were less likely to think of an orgasm as important. While the study authors say the fact that men actually enjoy the experience of having casual sex more “doesn’t explain the gender difference in regret,” it’s hard to argue that sexual satisfaction doesn’t make a bigger difference in walking away happy.

Previous studies have pointed to the “orgasm gap” between men and women who have casual sex: In a study of 12,925 students, Stanford and Indiana University researchers found that men were twice as likely to orgasm during a first-time hookup compared to women. But when in a relationship, women reached orgasm 80 percent as often as men. For these researchers, the difference isn’t because of an inherent biological difference; it’s because men didn’t try as hard as women to help their partner get there.

So a sexually liberated attitude doesn’t squash the anxiety women have about becoming pregnant by a one night stand; the fact that they aren’t orgasming at the same rate as men probably doesn’t help quell their regret either.

Photos via Giphy, Flickr/Tina Franklin