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Why do we yawn?


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August 27, 2015 9:05PM

Yawning It is actually still an unknown mystery of life. Though there are good hypotheses supporting why humans and animals yawn, they are not conclusive.

Any explanation about why we yawn will have to explain a number of interesting observations:

  • Yawning occurs even when oxygen and carbon dioxide levels are normal.
  • Yawning may make others yawn (that is, it seems "contagious") and may indicate behavior based on social cues.
Other hypotheses:
  • One is that when we are bored or tired, we just don't breathe as deeply as we usually do. As this theory goes, our bodies take in less oxygen because our breathing has slowed. Therefore, yawning helps us bring more oxygen into the blood and move more carbon dioxide out of the blood

    (This theory could be true, because I've never yawned while playing sports or running a mile before.)

  • Most people think it is that you are tired or there isn't enough oxygen coming to the brain. From recent studies it is because your head is over-heated.
  • Another person noticed that he had been sitting for about half an hour being bored and dreamy. When he stood up, he started yawning 2 or 3 times. Maybe his body was doing the opposite of maintaining homeostasis, preparing for an increased heart rate when his body stood up, as if about to start moving and needing oxygen.