Why Do We Yawn?
by Hsu Jia-wen · Oct 2026
Everyone yawns. Babies yawn before they are even born, and cats, dogs, and even fish seem to do it too. Yet scientists still cannot fully explain why we yawn. What seems like a simple action has turned out to be a small .
For a long time, many people believed that we yawn because our bodies need more oxygen. It sounds , but experiments have not supported this idea. When people breathed air with extra oxygen, they yawned just as often as before. Today, a more popular is that yawning helps to cool the brain. When we take a deep breath with our mouths wide open, cooler air and fresh blood may lower the brain's temperature. A cool brain works better, which may explain why we often yawn when we are tired or bored.
Another interesting fact is that yawning is "catching." If you see someone yawn, there is a good chance that you will yawn too. Some people even yawn when they read about yawning. have found that we catch yawns more easily from family members and close friends than from strangers. This suggests that yawning may be connected to , the ability to understand how other people feel.
Whether yawning cools the brain, keeps us , or helps groups of people stay in , one thing is clear: it is a normal and natural part of life. So the next time your classmate yawns in class, don't take it personally. Their brain might just need a little fresh air. And if you yawned while reading this, you are not alone.