what causes a chain reaction when someone yawns why do other peopl start to yawn aso?

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what causes a chain reaction when someone yawns why do other peopl start to yawn aso?

2007-07-01 09:29:33 · 2 answers · asked by mari 1 in Science & Mathematics ➔ Medicine

2 answers

Damn you! As soon as I read this question it made me yawn!

This was asked a few hours ago, have a look at those answers and see, I am not sure of the answer.

Take a look at this:
http://uk.youtube.com/watch?v=Cy-Pf6oJNRo

It made me yawn

Ashley

2007-07-01 09:48:32 · answer #1 · answered by Ashley 5 · 0⤊ 1⤋

There are several theories - it's physiological because we need more oxygen; it's evolutionary, because our ancestors did it for some reason; it's due to boredom (but the evidence for all three seems pretty thin!

2007-07-01 10:15:52 · answer #2 · answered by kt 7 · 0⤊ 0⤋