It’s Saturday night, you’re at a campus bar with your gaggle of girlfriends, and suddenly, amidst the circling cluster of sex-hungry guys, one particularly appealing male specimen catches your eye. You may talk and flirt with him, but when it’s closing time and the choice of leaving together is fast approaching, how do you tell if you’ve found Mr. Right or Mr. Just Tonight?

Determining if he’s just looking to hook up or if he wants a long-term relationship comes down to how, and where, he looks at you, says a new study from researchers at the University of Texas at Austin.  According to this study of 375 college males at UT, when a guy only checks out your body, it means he’s in it for the “wham, bam, thank you ma’am” short-term. He’s just looking to hook-up. But when a guy really focuses on your face, he’s looking for a long-term girlfriend or wife.

The researchers say these findings are reflective of humans’ basic evolutionary motives and indicative of natural selection. A man will check out your body most closely when he wants to sleep with you because he’s checking to make sure you’re not already knocked-up, and he’s searching for clues about your fertility. On the flipside, when a man focuses on your face, he’s looking for information about your personality, such as your intelligence, sense of humor or disposition.

So, how accurate is this study? It’s already facing criticism for the size and homogeneity of its sample: a group of 375 males that are all college-age and living in the same city in Texas isn’t a very well-rounded representation of the planet’s entire male population. Also, it’s very unlikely the behaviors of these men reflect evolutionary tendencies because our modern society is immensely different than that of our earliest ancestors. To truly test out evolutionary motives, wouldn’t it best to conduct research in a culture that most closely mimics those ancestors? Rowdy college boys at a big state university don’t fit the bill.

— By Ali Straka, University of Missouri