Ask Tappity: Science Questions for Kids > Why Do We Yawn?
Why Do We Yawn?
We yawn when we're sleepy, and when we see someone else do it. What's going on? Watch this video to find out, or read our explanation below!
Yawning Might Cool Down Your Brain
Believe it or not, scientists still aren't 100% sure why we yawn, but they do have a theory. At the roof of your mouth, there's a large artery bringing blood to your brain, and scientists know that your brain works best at a very specific temperature. Too hot, and you can't think straight. So yawning might cool down your brain's blood supply by flushing your mouth with air. Sort of like blowing on hot soup!
Lots of Animals Yawn
Humans aren’t the only animals that yawn. Lots of other animals do, including dogs, chimpanzees, and lions! Not everyone does it for the same reason, though. Guinea pigs, for example, yawn as an act of intimidation, to how other guinea pigs how big their jaws are jaws. Yikes!
Why Is Yawning Contagious?
Seeing someone yawn makes you want to yawn. And it's not just humans who do this - contagious yawning has been observed in other animals, too. Scientists still aren’t sure why this is, but one theory is that it's an evolutionary response that helps tell everyone to stay alert. In one study, people who were shown pictures of other people yawning were able to detect snakes faster than they had been able to before. So if you’re going snake-hunting, try watching someone yawn first!
Yawning Facts for Kids
Got yawning questions? We’ve got yawning answers!
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No. Despite this common explanation, multiple studies have failed to find any link between yawning and blood oxygen levels.
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Probably! One study showed that dogs were more likely to yawn after seeing a human yawn, but not more likely after just seeing a human open their mouth.
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For some people, yawning tugs on the lacrimal glands, which are responsible for tear production. That makes their eyes water when they yawn.
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Yes - your airway gets 3-4 times larger when you yawn.
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Yawning opens up something called your eustachian tube, a small passageway connecting your throat to your inner ear. This allows air to come into your middle ear, equalizing pressure. It's actually a lot like letting the air out of a balloon - when you go up high, the air pressure around you decreases, making the air inside you higher pressure than the outside - just like a balloon. Opening your eustachian tube gives the trapped high-pressure air in your middle ear a route to escape.
More Answers to Human Body Questions from Kids
Why do tears taste salty? What are eyebrows for? The Tappity Human Body Library has interactive lessons with answers to those questions and more!
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