Why Do We Yawn? The Mystery of the Universal Stretch

Have you ever seen someone yawn and suddenly felt the urge to do it too? That is called contagious yawning.

Long ago, people thought we yawned because we needed more oxygen or wanted to blow out stale air. But now scientists think our brains are like computers that can get too hot. When you are bored or tired your brain temperature goes up just a little bit.

A big yawn sucks in cool air from the room. This helps cool down your brain so it can work better. It is like opening the hood of a car to let out steam.

Even animals that do not have lungs like snakes yawn! This tells us that yawning is very old and important for all vertebrates. It helps prepare their muscles for action. Imagine your body getting ready to run or eat.

You might also yawn right after you wake up. This signals to your body that it is time to start the day. So next time you see someone else yawn do not be annoyed. Their brain is just trying to stay cool and focused.