Let’s face it, some people are just creepy. You can’t quite put your finger on why that guy is giving you the heebie jeebies, but you know he is. (And yes, it’s usually a he.)

Enter researchers at Knox College, who surveyed 1,341 people to try to nail down the concept of creepiness.

Get the better newsletter. This site is protected by recaptcha

Professor Frank McAndrew decided to study the concept when he realized everyone uses the word — but nobody knew quite what it meant. “I was absolutely floored to discover that there had never been even a single study of creepiness,” he told NBC News BETTER.

So he asked people to rate different behaviors on a creepy scale of 1-5. Watch the video animation to see how you rate.

Some things we consider creepy are clearly pretty skeezy — wanting to talk about sex too much, for example. But some are just physical traits we may not be able to control (looking at you, Steve Buscemi).

That “creepy” feeling is an emotional reaction when it's unclear whether something or someone poses a threat, McAndrew said: “It is unpleasant and it registers somewhere between disgust and fear.”

McAndrew is working on a book about creepiness now, and plans some experiments on people’s reactions to creepiness. He’s never felt too creepy himself, though “my research indicates that creeps probably do not realize that they are creeps, so who knows?”

We’ll give him the benefit of the doubt and assume he’s not into taxidermy.