6 - Why Do We Yawn?

Bears yawn. Camels yawn. Most mammals yawn. Why do we yawn? No one really knows the answer. We do know that everyone yawns in the same way. First, you open your mouth slowly. Your mouth stays open for about five seconds. Then you quickly close your mouth.

We also know that yawning is contagious, or catching. When you see someone yawn, you yawn too. Many people say that they yawn because they are bored or tired. This might be true. However, we know that people also yawn when they are excited or nervous. Olympic runners, for example, often yawn before a race. Why is that?

Some scientists believe that yawning makes you more alert. When you yawn, you breathe more deeply. You also stretch the muscles in your face and neck. Maybe this makes you feel more alert.

Scientists don't spend much time studying yawning. That is probably because yawning doesn't hurt. It is just something we do.