Author and behavioral scientist Coltan Scrivner, who is a research fellow at the Recreational Fear Lab at Aarhus University, and has pioneered the psychological study of morbid curiosity, says that our initial instinct is to avoid looking at these things because we fear that what we see will not be pleasant.

But just think of horror movies. There's a jump scare and the bad guy is on the screen. Half the audience covers their eyes in terror, while the other half is glued to the screen. However, even the people that are covering their eyes peak through their fingers from time to time to keep an eye on the killer. 

Why do we do this? Why do we subject ourselves to fear and anxiety?

To understand it, Scrivner suggests starting with real situations. "The car wreck story is a bit old and tired, but it's a good example because it's something that almost everyone has experienced and can intuitively understand," he writes.

"It's true for almost everyone that you don't want to see someone injured and you don't hope anyone died in the wreck. But, if they did, you do feel compelled to look at it."

That's mainly due to the simple fact that our ancestors lived in dangerous places. "The world today can also be dangerous, but even the most basic treatments that are available today can severely decrease the seriousness of an injury. If you got injured 10,000 years ago (or even 100 years ago), your chances of surviving were far less than they are today with modern medicine," Scrivner explains.

"Even if the blood loss didn't kill you, an ensuing infection might. This placed a premium on avoiding danger—or at least avoiding the consequences of danger."

But to avoid danger, you must first know something about it. You have to recognize it. After all, the more you know about something, the better you can predict it. And the better you can predict it, the better you can deal with the consequences if it does occur.

"This is where curiosity steps in. I don't want to be in a car wreck myself to find out how bad a car wreck is. I also don't want someone else to be in a car wreck. But if they are, I do want to know how bad it is. This could inform my current decisions and behavior," Scrivner says.

For example, if the car wreck is particularly gruesome, it might cause a person to slow down or be extra cautious the rest of the day, which will decrease the chances of the same unfortunate event happening to them. (If it's just a fender bender, it may not affect their driving behavior very much.)

"The consequences of threats have left their mark on our psychology and influence our behavior in response to 'morbid' situations," Scrivner says. "This has resulted in most of us having some morbid curiosity, and some of us having a lot of it."

This psychological tendency has also played out in large-scale human behavior numerous times. Whether we're talking about the Roman gladiatorial games or the presence of death in rituals and religion. The spectacle of public executions. Or the massive fan base surrounding the true crime and horror genres. Coloring each of these phenomena, according to Scrivner, is a tendency for humans to be morbidly curious.

So now we know that the best way to avoid the consequences of a threat is not to simply avoid it. "Avoidance might get you away once or twice, but it's not a good way to deal with future encounters," Scrivner explains. "It's more efficient and more productive to first learn something about the threat. This way you can know how to identify, avoid, or deal with it in the future."