whats logic behind yawning ????

that's a really interesting question. i totally got curious and searched online for an answer! i wanted to know why myself. they say a possible cause for contagious yawning is our 'mirror neurons'. when they get exposed to a stimulus, they activate the same regions in the brain. mirror neurons, they say, are also considered as a possible driving force of imitation which is important in our acquisition of language. so yawning when seeing someone else yawn is another impulse to imitate. haha. i'm glad i learned that too.(^_^)

I don't know if its true but my instructor told me before that its a body reaction - just like vomiting - a self defense mechanism of the body. When there is to much carbon dioxide in the body, therefore it triggers the body to yawn in order to gather more oxygen. But the question of why its contagious is still a mystery. ^_^ Happy mylotting!

I could say that this is one of the most interesting topics I have so far, come across with. Researchers said that this is somehow an archaic act. This means that it may have existed even from the start of our species' existence to ensure survivability as usual.This kind of phenomenon may have synchronized their sleeping time and their alertness level. When scientists try to look for the brain activity when this phenomenon happens,they found out that there is no activation in a certain part of brain that could be responsible for it. Instead, they found that there are certain inactivation of activity in some parts of the brain. It is like it was just shut off unconsciously. Until now, they could not really come up with a palpable conclusion. :D