| Down to a Science |

What Is a Yawn?  

The first and simplest reason why people yawn is because they’re tired

Hello, kiddos,

This is Professor Mordy Maven, Thinker, Wonderer, and Figure-Outer of all things Science-ish. What that basically means is I try really hard to figure stuff out. I do the hard work so you don’t have to!

A funny thing happened today and I thought I’d share it with you. And I meant to, I really did! But I couldn’t because I just couldn’t stop yawning! And here’s the really strange thing — I wasn’t even tired! I mean, I’d slept a whole bagel the night before! I only started yawning because my brother was yawning and he wasn’t tired either. He said he was just hot.

A yawn is a reflex that stretches your eardrums while you inhale and then exhale. But you probably already knew that! Yawning is a really common thing to do. After all, almost everybody yawns, old people, crocodiles, and fish! But let’s just talk about people. (Not like lashon hara or anything, of course! Just about yawning.) A human being’s average yawn lasts about six seconds, and men generally yawn longer than women. During that six seconds, a person’s heart rate can increase by as much as 30 percent.

Fascinating, right? But that still doesn’t tell me… why do people yawn?


Well, the first and simplest reason why people yawn is because they’re tired. You know, like the morning after Seder night when everyone you meet is opening their mouth so wide you feel like you’re talking to their tonsils? When you yawn, the air you inhale stretches your lungs and causes the body to flex its muscles and joints. It also sends blood to your face, which wakes you right up.

And then there’s the middle-of-grammar-class yawning. That type happens because you’re bored. As in, I am yawning, he is yawning, they are yawning, I yawned, she yawned, I will yawn…. Yawn! The reason you yawn when you’re bored in grammar class is because your brain doesn’t feel stimulated and it starts to slow down, which causes a drop in temperature. You yawn so that you can inhale air to help cool down your brain. Yep, you heard me right. Grammar class can actually shut down your brain. Terrifying!

This is also the reason that people yawn when they’re too warm. That rush of air cools the brain down, which wakes the brain up. I guess you could say a yawn is an ice pop for your brain!

So sometimes you yawn because you’re too tired or too warm or too bored. That’s called spontaneous yawning. But here’s something weird. Sometimes you yawn because… someone else yawned. In fact, sometimes you’ll start yawning just because you saw a video of someone else yawning! And it doesn’t only happen when you actually see a yawn. Studies have proven that blind people who hear the sound of someone close to them yawning will start yawning, too!

Which is really nuts. I mean, I never sneeze just because someone else sneezed! I hardly ever hiccup because someone else is hiccupping. So, why do we yawn because someone else is yawning? The answer is really quite simple and it’s called echophenomena.

Echo who? Echo what? Echooooo… Echooooo….

You heard me (you probably heard me twice. Get it? Because it’s an echo! Haha!) Echophenomena is the automatic imitation of another person’s words or actions.

I know what you’re thinking: I’m not a copycat! I’m an original! I’m unique. I’m me, myself, and I! Well, maybe so but echophenomena is pretty common. (I guess you’re not that unique after all, huh?) It’s triggered by reflexes in the primary motor cortex, the area of our brains responsible for all kinds of movements. This type of yawning is called contagious yawning. And while lots of contagious things are bad, this particular one is a good thing.

What makes it good? Well, contagious yawning is a good thing because it is linked with empathy.

Empathy means the ability to feel what someone else is feeling. When researchers studied yawning, they discovered that people are most likely to experience contagious yawning when they’ve seen someone in their family yawn. Second after that is when they see a friend yawn, then an acquaintance, and least of all when a stranger yawns. This made the researchers think that yawning is a way of empathizing with people we care about and showing them that we share their emotions. It’s like you’re saying, I see you’re hot, bored, tired, or just sick of doing grammar. And I’m with you, my friend!

And guess what? The harder you try to stop yourself from yawning, the more likely you are to end up… yawning! (Also the harder you try to stop yourself from laughing, but that’s another story!)

To sum it up, yawning happens when your brain is bored, tired, warm, or feels really connected to someone else so it opens your mouth wide and sucks up all the air in the room. Simple, right?

fascinating facts about yawning

Contagious yawning isn’t just for people, it happens to chimpanzees, baboons, and even dogs!


It doesn’t matter whether the person yawning is upside down, right side up, or sideways. No matter their position, you can “catch” their yawn!

People sometimes use caffeine to help wake them up but too much caffeine actually causes yawning!

I hope that helped solve the mystery for you, kids.

And with that, I’m hopping off to my next quest…

(Originally featured in Mishpacha Jr., Issue 832)

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