Bears yawn. Camels yawn. Most mammals yawn. Why do we yawn? No
one really know 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 scientist 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 make you feel more alert.
Scientist don’t spend much time studying yawning. That is probably
because yawning doesn’t hurt. It is just something we do.
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