Short Wave - Why Do We Laugh?

Episode Date: October 13, 2022

Laughter: We do it spontaneously, we do it forcefully, we do it with each other and by ourselves. But why did we evolve to giggle in the first place? Emily and Regina explore the evolutionary underpinnings of laughter — from chimpanzees to modern-day humans — and the ways it unites us. Keep laughing with us on Twitter — we're at @NPRShortWave — or email the show at [e-mail] pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

Aloha. This is Charlene Dyer speaking to you from Kilauea, Hawaii, and Kaua. My name is Asia, and I'm from Chicago, Illinois. Rachel Percy, Dressel, Ganderard, and we're from Charleston, South Carolina. Rosie from Westchester, New York. Your three are made. Ha'ole La Hanna. Happy birthday shortwave. And you're listening to Shortwave. From NPR. All right, Regina, I have a question for you. What makes you laugh the most these days in this world? Right now it's like surprising everyday stuff like joyous bad karaoke or my daughter and I just like talking to each other will just start laughing.

What about you, Emily? Like what makes you laugh? Yeah. I think I might be amused by myself. Me too. Like my sleep app recorded this choice piece of audio a few nights ago. I sound like a witch. Just in time for Halloween.

I wonder what you were dreaming about. That's a whole other shortwave episode. Laughter feels so good. And there's lots of evidence to support this. When you laugh, Regina, you increase your oxygen intake. You basically activate then cool your nervous system. And what follows are lower stress hormones, lower blood pressure, and less tension with all these delicious endorphins swirling around. I do feel that release, that relaxation after I laugh.

Actually, right even now when we're talking about it. But there's probably like a physiological benefit too, right? Yeah. So in recent years, researchers have shown laughter may be linked to a boost in immunity. It may increase infection-fighting antibodies and killer T cells. Harborview Medical Center in Seattle, close to you, actually has a laughter club where doctors and patients and staff can go to blow off steam. Laughter is a short distance between two people. Tida Bega Shah is the hospital's patient service specialist and leads the laughter club.

Shortwave senior editor Gabriel Spitzer interviewed her a few years back. When you feel good, you're able to support your patient in the positive way. You don't get stress. We hear and then now. Look at the wind. Open your arms. Say thank you. Here and the now.

I love this lady. She's kind of like. It's iconic, right? Yeah. Science has given us a pretty good sense of how laughter changes our minds and bodies. But what I wanted to know is, why do we do it? Like, what evolutionary purpose does it serve? So today, Regina, I want to take a gander down the merry path of scientific literature

and maybe share some LOLs along the way. I bet I'm going to make you laugh before you make me laugh. I'm very competitive. Yeah, okay, you're on. I'm Emily Kwong. I'm Regina Barber. And you're listening to Shortwave from NPR. So, Em, how do you want to do this?

All right. Well, first I want to do a disclaimer. We're focusing today on laughter, not humor. Good. That's a whole other can of worms. Okay, so evolution-wise, laughter is ancient. Researchers think it evolved at least 10 to 16 million years ago. It's also instinctual. And to show you that, I want to pass the mic to the youths. This is one of my favorite videos on the internet. It's a video of a dad ripping up a job rejection letter in front of his eight-month-old. who found it hilarious, like high comedy. It is so cute. It's so cute. And like, Regina, Micah can't talk yet. He's little, but he can truly laugh. He can like guffaw on par with a grown man.

We humans, we start laughing as early as three months of age way before we can speak, which means that laughter is one of the first ways we connect. A few years ago, developmental psychologists Casper Addyman and his colleagues asked parents around the world what made their baby laugh. 1,500 responded from 62 countries, and the clear winner, the stand-up comedy bit that brought down the baby house, was Peekaboo. Of course it was. Of course it was. I totally remember doing this with my daughter when she was a baby, Dory. But I'm going to tell you something, Emily.

She actually played peekaboo with me a few months ago when I was very tired at night. Where'd you go? Whoa. Okay. Good night. You realize in this situation, you're the baby, right? And she's the parent. Yeah.

Yeah. She, like, dropped down, and then she came up in a different location. It freaked me out. It's reliable, you know, peekaboo slaps. And Dr. Addyman says it's because it starts off with a connection, right? We're like, hello? And that connection is lost. And then it's found.

And then it's lost. And then it's fun. No, you're getting me now. No. The return of eye contact, the sharing of a moment. That really makes us laugh. When you do this, the baby realizes that it's got adults' attention. Adults' attention is gold dust to little babies.

And laughter is their payment in kind. And that's Caspar Addyman and his TEDx talk. This audio is courtesy of TED. Laughter as payment for attention. I mean, this makes sense, right? That's what I crave from friends, right? Exactly. And you don't need a lot of friends around to make that happen.

So in a lab study, Dr. Adyman found that preschoolers watching a cartoon laughed on average eight times more when they were with another kid than when they were watching cartoons by themselves, even when they reported finding the cartoons just as funny solo. And the children didn't laugh anymore with more kids around. Just one person was enough to get them giggling. And this suggests that laughter is more than a contagious reaction. it's actually like a signal to each other that someone else is there. What we're laughing at is not the things in front of us, but we're laughing with the people next to us. In fact, the children who were alone watching the cartoons, they kept trying to catch the researchers eye in the funny moments,

anything to kind of build a bridge. So it really is a way to try to connect with each other. Exactly. Now, a word of caution, you're probably thinking this too. There are different kinds of laughter, right? There's volitional laughter, like that kind of forced laugh you do. do to be polite. Oh, like this. That was so, that was painful, man. You know, study show you can tell the difference between the two. No, what we're talking about in this episode is spontaneous

laughter, involuntary laughter that busts out of you, you can't control it. And for this, I want to turn to the work of the late great neuroscientist and professor of psychology, Robert Provine, at the University of Maryland. He spoke to NPR's here and now back in 2016. Laughter is one of a series of inborn human behaviors, along with things like coughing and sneezing, belching, farts, the list goes on and on. And for his book, Laughter, a Scientific Investigation, Dr. Provine and his colleagues recorded 1,200 laugh episodes at cocktail parties and shopping malls and class reunions, just moments that sparked laughter between people. Yeah. And Gina, they found out that a lot of laughter has nothing to do with humor. In their data set, only one in five laughs were generated by something joke-like.

The rest was all an act of social engagement. The source of laughter or other people, not jokes. Now, for example, most laughter follows comments like, hey, where have you been? This is a conclusion that's easy to test. Next time you're around friends and there's a lot of laughter, people are not telling each other jokes at a furious rate. They're just laughing. That totally reminds me of when my job. daughter was a baby and she's in her high chair and we're having this dinner party with adult

friends and we would laugh at a joke and then there'd be this delay and this she was she couldn't even talk yet and she'd just be like ha ha ha ha because she just wanted to be part of the conversation you know that little dory was making a connection and what's super interesting to me too is that among these 1,200 laugh episodes the person making the laugh provoking statement was actually more likely to laugh than the person listening so You can really think of laughter as a social behavior that we do to influence the behavior of others. And we're not the only species that does it. Here's Dr. Provine again.

If you tickle a chimpanzee, it makes its own special kind of laughter. In fact, I can imitate it for you. Sounds like panting. Okay, well, the pant-pant sounds of chimpanzees has evolved into the ha-ha-ha-ha-sound of modern humans. And this important transition, and it gives clues about where a human-type laughter came from. Laughter is literally the sound of labored breathing of rough and tumble play. The difference is that somewhere along the way, we humans lost the inhalation part. Our laughter is just the exhalation, the ha.

So when you belly laugh with abandon, that's why you lose your breath. You're emptying your lungs. And you could say, dying of laughter. I mean, come to think of it, it does kind of hurt. sometimes. A big laugh does, but it feels so good, right? Yeah, there's nothing more cathartic. Yeah, so the question becomes, how did this vocalization we hear in non-human primates evolve into the human laugh we know today? What purpose does it serve? Well, Robin Dunbar, professor of evolutionary psychology at the University of Oxford, has a guess. He says it may have to do with a behavior

that is really common among monkeys and apes. What? Social grooming. Like, clean each other's fur. Yeah, like one animal leafing through the fur of another to pick out dirt and insects. It does keep the fur clean, but this behavior also strengthens social bonds. The movement of the hand across the skin in particular, when it moves the fur, triggers a very specific neural mechanism that only responds to light, slow stroking. And this movement, this light, slow stroking, it triggers. triggers the endorphin system. And endorphins promote social bonding in humans and other primates. So Dr. Dunbar believes that laughter is something our species evolved to supplement social grooming, to produce the same endorphin release and to help us feel warm and close to one another.

Our anxiety at some point started to effectively have choruses around the campfire, as you might think about it. where everybody's sitting around and somebody starts laughing and it triggers everybody else off. And this is reflecting the fact that laughter is immensely catching. If somebody laughs in your little group, you can't help laughing, even when you didn't hear what the joke was. Everybody else falls apart. This is fascinating, right?

Like, this is our third birthday, shortwave's third birthday is coming up. And I've been thinking about how much laughing we do on this show, even preparing for this birthday, right? Oh my God, it's disgusting how much laughing we do. I can't believe we get paid for this. Okay, I'm going to try to be sincere for a second, which is really, really hard for me. But I want to say thank you to our listeners

for laughing with us these last three years. We have so much fun making this show. And it's so chaotic making this show. True. It's very chaotic. It's so chaotic. In fact, if you want to get a glimpse into the chaos machine that's shortwave, follow us on Twitter. Our show is at NPR Shortwave.

wave. And I'm at Emily Kwong, 1234, which is not a handle I'm proud of, but it's the handle I have. I'm at Science Regina. All this week, we're sharing stories on Twitter of some of our favorite moments and epic fails that make our show what it is. The audio you heard in this episode from

Kasper Addyman is from his TEDx talk, Why Babies laugh, given at TEDx Vrodislava. You can see the full video on TED.com, and for more TED in audio, follow the TED Radio Hour with NPR, wherever you're listening to this. Today's episode was produced by Chloe Weiner and Margaret Serino, edited by Rebecca Ramirez, and fact-checked by Marge and Ubi-Levin. Josh Newell was the audio engineer.

Giselle Grayson is our senior supervising editor. Brendan Crump is our podcast coordinator. Our senior director of programming is Beth Donovan, and our senior vice president of programming is Anya Grenman. Thanks for listening to Shortwave, the Daily Science Clowncast from NPR. Thank you.