Feeling bored? Tired? Just woken up? What do you do? You pandiculate!!! In other words you stretch yourself and let out a loud yawn. Have you wondered what makes you yawn? Scientists have pondered over this and have come up with several explanations.
A yawn is the body’s way of telling you that it needs more oxygen. Scientists speculate that you yawn either due to fatigue, or by sheer boredom because, at those times, breathing is shallow, and little oxygen is carried to the lungs.
Yawning, (one yawn takes just about six seconds),opens up the respiratory system. There is a sudden increase in oxygen, the accumulated carbon dioxide is eliminated, restoring normal breathing and alertness. A message that we must yawn comes from the “yawning center” of the brain, located in the hypothalamus, which releases substances, which in turn, induce a yawn.
Whatever the reasons, we do know that a yawn is contagious. When someone next to you yawns, you find it difficult to stifle yours. This has made scientists wonder whether a yawn was some kind of a communicating behaviour in animals, where yawns were used as a signal to indicate an event. Going by this theory, scientists feel that maybe yawning is simply a signal to let people know that you're tired, just as, smiling is to let people know that you're happy and crying is to tell people that you are sad.