While the exact definition of what each of us considers eerie differs, the underlying cause is more or less the same.

"[Creepy is] about the uncertainty of threat. You’re feeling uneasy because you think there might be something to worry about here, but the signals are not clear enough to warrant your doing some sort of desperate, life-saving kind of thing,” Frank McAndrew, professor of psychology at Knox College in Illinois, United States, explained.

Even the way our bodies respond to the triggers is similar.

In 2012, researchers from the University of Groningen in the Netherlands found that when subjects felt creeped out, they felt colder and believed that the temperature in the room had actually dropped.

Chilling, indeed!

That physical response further heightens our senses.

"You don't know how to act but you’re really concerned about getting more information," McAndrew said.

"It kind of takes your attention and focuses it like a laser on this particular stimulus, whatever it is."

As we can see from the pictures, it can be a lot of things, situations, places and, of course, people.

"We're predisposed to see willful agents that mean us harm in situations that are ambiguous, but this was an adaptive thing to do,” McAndrew said.

Our ancestors saw saber-toothed tigers in every shadow and a slithering snake in the motion of the swaying grass because it was better to be safe than sorry.

McAndrew pointed out that truly creepy things and situations are not attractive. At all.

"We don't enjoy real creepy situations, and we will avoid them like the plague," he said. "Like if there's a person who creeps you out, you'll cross the street to get away.”

What we do enjoy is playacting, in the same way we enjoy the thrill of watching a horror movie.

McAndrew and other psychologists, anthropologists, and even author Stephen King agree that horror films are a safe place for us to explore our fears and rehearse what we would do if, say, zombies tore apart our town.

Maybe these TikToks are too?