One Neuroscientist Explains The Science Of Laughter

Laughing is something most people do every day, but chances are we don’t really understand why we do it.

Robert Provine, a neuroscientist and professor of psychology at the University of Maryland, Baltimore County, explains the science of laughter to Here & Now's Jeremy Hobson. Provine's most recent book is "Curious Behavior: Yawning, Laughing, Hiccupping and Beyond."

On laughter as something people do involuntarily

"Laughter is one of a series of in-born human behaviors, along with things like coughing and sneezing and yawning, belching, farting, the list goes on and on. And laughter, we do it all the time, but it's a topic full of surprises, because a lot of things that everyone thinks they know about laughter — not true.

"For example, we say we laugh for this reason or that reason. And yet laughter's not under conscious control. We have the same kind of difficulty laughing on command that we have crying on command. When we explain why we laugh, we're assuming this voluntary control, and it's not there. Another surprise is that laughter is presumed to be somehow related to humor, and yet only 10, 15 percent of comments preceding laughter are anything that's remotely joke-like."

"Laughter, we do it all the time, but it's a topic full of surprises."

Robert Provine

On what causes people to laugh

"The source of laughter are other people, not jokes. For example, most laughter follows comments like, 'Hey, where have you been!' It's not someone telling a joke. This is a conclusion that's easy to test — the next time you're around friends and there's a lot of laughter, people are not telling jokes at a furious rate, they're just laughing. Also, the presumption that laughter's the decision to speak 'ha ha' can be easily disproven by asking someone to laugh.

"...Laughing and crying, yawning and so many of these other behaviors, are things that we do all the time, but they're not under conscious control — they simply happen. So while humor is not usually the result of jokes, it is the result of engaging in playful activity around other people. Laughter occurs 30 more often in social than solitary situations. In other words, if you want more laughter in your life, simply find people who you like and spend time with them."

On how tickling offers insight into laughter's roots

"When someone is tickled and laughs, we're getting a very deep insight into where laughter came from. Especially if you don't tickle another person, you tickle a chimpanzee. If you tickle a chimpanzee, it makes its own special kind of laughter... it sounds like panting. If you play that sound of real laughing chimpanzees to a naive audience, hardly anyone says it's laughter. They'll say, 'Oh it sounds like panting, maybe of a dog.' Well the pant, pant sounds of chimpanzees has evolved into the 'ha ha' sound of modern humans, and this important transition gives clues about where human-type laughter came from. Laughter is literally the sound of labored breathing of rough-and-tumble play. So the panting sound of chimpanzees is the sound of their labored breathing. It's the sound that one playful chimpanzee sends to another, saying that, 'I'm playing with you, I'm not attacking you.'"