The internet allows you to effortlessly look at things you might never be able to see IRL, like the Taj Mahal, an old Rachel McAdams audition tape, or a kitten playing with a hedgehog. Then there are the images you're not as quick to share on Faceook—the infected wounds, burst cysts, broken bones sticking through skin... Ew! And yet we just keep clicking.

Checking out freaky things on the internet can make you feel alternately nauseated, anxious, ashamed...and kind of excited. What's going on with this impulse? There's a clear psychology to this act, experts say, as well as a biological imperative. The explanation might make you feel a little bit better about your browser history.

Compared to happiness, sadness, fear, and anger, disgust shows up fairly late in a baby's developmental process, says Alexander J. Skolnick, Ph.D., an assistant psychology professor at Saint Joseph's University. "Around age two, parents use disgust when a baby's being toilet-trained," he says. "They'll say, 'Don't play with your poop, don't touch it, it's gross.'" The same shaming concept is applied to peeing in their diaper, putting food in their hair, trying to eat dirt, and so much more. (Such as, eating food after you drop it. Speaking of, find out What Science Has to Say About the 5-Second Rule.)

"The evolutionary idea is, what's functional about disgust? It keeps us safe," Skolnick continues. "Rotten food has a sour, bitter flavor, and that's a cue to us. We spit it out." The weird taste and nasty smell protect you from eating bacteria that might make you sick. Photos or videos of wounds serve a similar purpose. Skolnick often kicks off one of his psychology classes by encouraging students not to Google image search "recluse spider bite"—though, of course, they do, and you might right now. "Sometimes we're disgusted when we see someone with red rashes or welts. We don't want to stand next to them. That disgust keeps us safe from contagious elements."

So if that explains why we need disgust, why do we like disgust (you know you've clicked play on at least one cringe-inducing video that's popped up on your Facebook feed)? Clark McCauley, Ph.D., a psychology professor at Bryn Mawr College, has some ideas. "It's similar to why people go on roller coasters. You feel fear, even though you know you're safe," he says. "You get a big arousal value out of them." Of course, physiological arousal doesn't just refer to sex; think of all the different activities that get your breath pumping and heart racing. "Arousal has a positive component, as it hits this reward track," he explains. (Which explains all The Weird Reasons You Love Amusement Parks.)

Skolnick also compares Googling gross stuff to watching a scary movie. The whole point is to freak yourself out in a completely controlled, secure environment—you're never really in danger. The internet, of course, makes it even safer—all you have to do is close out of a window and the scary thing disappears. Plus, no one ever needs to know you chose to look in the first place, provided you scrub your browser history.

We're not all fear-seekers, or freaks for that matter. Skolnick believes that this need to Google can also be chalked up to genuine human curiosity. "We want to know what's gross out there, what's awful out there," he says. When it comes to odd sex fetishes, "you don't want to watch the sexual acts, you just want to know what's out there," Skolnick explains. (Learn more about Your Brain On A Sex Fetish.)

If you're still feeling worried about a generation raised on infected wounds and bizarre porn, rest assured that the internet may be new, but the need for gross stuff is not. "People aren't more immoral," McCauley says. "They're not different, but their accessibility is." So even if you're obsessed with reading creepy stories on Reddit, know that your great-grandmother would have been wired the same way. The only different is you know to 'clear history' after you indulge.