Chimps do it, dogs do it, lions do it, even babies in the womb do it Photo: AFP
From The Telegraph:Far from being bad manners, yawning is a sign of our deep humanity, says Steve Jones.
What may become 2010's Conference of the Year has just been announced. The International Congress of Chasmology will take place in June in Paris, and papers are solicited now. Anyone bored by that statement should read further, for the topic to be discussed is not diving but yawning ('chasmology' deriving from the Greek word for the pastime).
Why do we yawn? Dogs do it, lions do it, even babies in the womb do it - but nobody really knows why. Theories abound. We open wide when we are tired, bored, or hungry. Some have suggested that a sudden drop in blood oxygen, or a surge of carbon dioxide pumped out by a tired body, sparks it off – but no, breathing air rich in that gas, or with extra oxygen, makes no difference.
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