Why we: a) laugh b) love TV c) have nightmares

30 Rock makes you laugh uncontrollably. You have nightmares after watching The Walking Dead. And you can’t tear yourself away from the new season of House of Cards. But … why?

Jim Davies is a cognitive scientist, and he looks at the reasons why art, jokes and religion all affect our brains.

Why We Laugh

Davies says that we laugh because people want to communicate something. We want to tell others that everything’s OK, despite the fact that the situation may seem a bit tense. The theory is called "benign violation." So, a joke will set you up to assume one thing, and then deliver something completely different. Like in the awful, awful gag: “There are two fish in a tank, one of them turns to the other and asks, ‘how do you drive this thing?’” You laugh because your expectations have been violated, but in a safe way.  

It’s not just jokes that can make you laugh, though. Davies explains that “in the lab, they’ve got these experiments where they have people lift things, and they’re all of a constant weight, and then the fifth thing is significantly lighter or heavier. And when they lift it, they laugh. Just violation of expectation is enough to elicit laughter.”

Why We Have Nightmares

Shockingly, there’s also a good reason we have nightmares. Dreams are (at least according to one theory) rehearsal for threatening situations. So, let’s say you watch an episode of The Walking Dead. You see zombies chase and kill off characters, and then when you go to bed: surprise surprise, you have a nightmare where zombies chase and kill you. According to Davies, “it’s your mind thinking, I’ve seen zombies, I need to prepare for what’s going to happen when zombies start attacking me. It’s a maladaptive-fear generating thing. Basically, evolution hasn’t had time to catch up and help us distinguish fantasy from reality."

Why We Can't Get Enough of our Favorite Shows

Our brains can’t distinguish fantasy from reality. That’s it. Intellectually, we know that Lord Grantham’s poor business decisions haven’t actually put Downton Abbey in peril, but emotionally? Completely different. “There really seems to be only one anger pathway in the brain, only one sadness pathway, and it happens in the older part of the brain called the limbic system.” Davies points out that “those parts are activated whether you are experiencing a real event or a fictional event.” Your brain has evolved to think gossip and drama are important to your survival, because back when we lived in groups of a couple dozen people, they were. And because the limbic system sees no difference between what’s happening on House of Cards and what’s happening in your social circle, it’s easy to while away the hours watching Frank Underwood’s duplicitous machinations.

This story was adapted from an interview on the PRI radio show Innovation Hub.