Most women have probably experienced being friendly around a man, only to have it be misinterpreted as flirtatiousness. Simple signals of interest in a conversation — smiling, laughing, being interested in a conversation — are all somehow perceived as come-ons. Straight men, research has found, are a lot more likely than straight women to fool themselves into thinking someone is romantically interested in them when they aren’t.

But what accounts for this gender difference? As Mons Bendixen, a psychologist at the Norwegian university of Science and Technology, writes in a study recently published in Evolutionary Psychology, there are two main theories: Error-management theory argues that men have evolved to overperceive sexual interest in non-familial female relationships so they don’t miss out on the opportunity to reproduce — at best, they get to pass on their genes; at worst, the woman ends up saying no and they move on.

Women, on the other hand, have evolved to underperceive sexual interest, because sex with the wrong guy means risking pregnancy and child-rearing without the help of a mate, not to mention lost opportunities to procreate with other, less flaky men.

In other words, the sexual stakes are higher for women than for men — or they were, at least, in the distant past, when evolution shaped behaviors that linger to this day.

Social-roles theory, on the other hand, argues that gender differences in rates of sexual misperception — not to mention in other sorts of behavior — come down to societal norms and expectations. So in places that lack gender equality, one would expect a large disparity between men’s level of misperception and women’s, with the rates becoming more and more similar the more gender-egalitarian a culture is.

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Bendixen realized that if the social-roles theory were true, it would probably show up when you examined rates of sexual misperception in different countries. In places where there’s more equality between the sexes, the social-roles theory would predict that men would misinterpret women’s interest about as much as women misinterpret men’s. If, on the other hand, error-management theory is true, then men’s levels of overperception would be consistently higher everywhere, since the bias comes down to evolutionary hardwired gender influences.

So Bendixen decided to try to replicate a famous 2003 study about gender-based differences in sexual misperception — one that took place in the United States — in Norway, which is known for being very solid on the gender-equality front: At the time of the study, it was ranked in the top five most egalitarian countries on the U.N.’s Gender Inequality Index, as compared to the U.S.’s rather cringe-worthy rank of 42.

These differences extend down to the dating world, Bendixen explained in an email. “Norway is very sexually liberal compared to the USA,” he said.

“A Norwegian woman can play a more active and proactive part in the dating game than an American one without being subject to the same degree of derogation.”

Bendixen’s version included 308 heterosexual university students between 18 and 30 years old, and he asked them the exact same questions that were posed in the American study. The results were overwhelming: 88 percent of women reported having experienced at least one incident in which their friendliness was misinterpreted as sexual interest by a man, and on average it had occurred about 3.5 times in the last year alone. Men also reported experiencing sexual misperception, but the rate — 70.6 percent — was far lower.

These rates were pretty similar to what was found in the original, U.S.-based study, which found that around 90 percent of women reported that their friendliness had been misperceived at least once in their lifetimes, on average 2.7 times in the last year, with about 70 percent of men reporting having experienced this.

The results, Bendixen argues, suggest that men’s misperception of friendly signals can’t be traced back to unequal opportunities for men and women or misogynistic culture; rather, he thinks sexual misperception occurs across different cultures and demographic groups, because it’s a universal evolutionary adaptation.

“Despite America and Norway’s cultural differences, the findings suggest that men and women make systematic errors in their attempt to read each other’s minds in dating and mating contexts,” he said. “These errors follow the predictions of error-management theory.”

Two studies can’t fully unravel how this stuff works, of course: There’s still a lot to learn about how nature and nurture interact when it comes to sexual misperception, particularly in countries that, unlike the U.S. and Norway, aren’t “weird” — that is, Western, educated, industrialized, rich, and democratic. Still, Bendixen’s work does score a point for those who believe that deep gender-based differences can strongly influence behavior.

So, ladies, the next time a guy misinterprets your friendly smile in a sleazy way, try to keep in mind that somewhere deep in his brain, he may still be a bit of a caveman.

This article originally appeared on Science of Us: Why Men Always Think Women Are Flirting With Them. © 2014 All Rights Reserved. Distributed by Tribune Content Agency.