Is it possible for straight guys and gals to ever be “just friends”? As Adrian F. Ward, a doctoral candidate in psychology at Harvard University, writes for Scientific American, “Few other questions have provoked debates as intense, family dinners as awkward, literature as lurid, or movies as memorable.”

Though daily experience suggests that non-romantic friendships between the sexes are the norm, scientists have something to say about that, suggesting that we might delude ourselves into thinking it’s not a big deal to be “just friends,” when in reality, all sorts of lurid feelings and impulses lurk below the surface, just one tequila shot away.

To arrive at this conclusion, researchers invited 88 pairs of undergrad, opposite-sex friends into their lab. They promised the participants absolute privacy, meaning neither party could learn what feelings the other may or may not have confessed to. As an extra precaution, the researchers made both friends agree, face to face, never to discuss the research in front of each other. Confidentiality established, the pairs split into separate rooms where they were asked a series of questions about their romantic feelings towards one another.

The scientists say their results suggest a significant difference in the ways men and women experience opposite-sex friendships. Ward elaborates:

Men were also more likely than women to think that their opposite-sex friends were attracted to them—a clearly misguided belief. In fact, men’s estimates of how attractive they were to their female friends had virtually nothing to do with how these women actually felt, and almost everything to do with how the men themselves felt—basically, males assumed that any romantic attraction they experienced was mutual, and were blind to the actual level of romantic interest felt by their female friends. Women, too, were blind to the mindset of their opposite-sex friends; because females generally were not attracted to their male friends, they assumed that this lack of attraction was mutual. As a result, men consistently overestimated the level of attraction felt by their female friends and women consistently underestimated the level of attraction felt by their male friends.

Men—perhaps not surprisingly—were more likely to act on those misguided feelings and put the moves on their friend than women in the same position.

The results suggest that, compared to women, men have a harder time accepting the “just friends” label and that two people can experience the same friendship in radically different ways, which may lead to trouble down the road. Ward concludes:

So, can men and women be “just friends?” If we all thought like women, almost certainly. But if we all thought like men, we’d probably be facing a serious overpopulation crisis.

More from Smithsonian.com:

Do We Really Pick Our Friends Based On Genetic Similarities?

Mark Twain’s “My Platonic Sweetheart”