I have to know this..... What is a yawn and why do we do it when we are tired??? And why is it contagious??

Answer 1

Humans yawn when the oxygen levels in their blood begin to drop. This is usually caused by irregular breathing patterns brought on by fatigue.

the reason that it's contagious is that when you see someone yawn, your subconscious mind speculates that the person is yawning because of a lack of breathable oxygen. It creates a survival response in you which manifests as a yawn.

In other words, it's your bodies attempt at stealing the last of the air in the room. :)

Answer 2

when we yawn it is a sign that our brains are not receiving the amount of oxygen it needs, mostly because your body is tired. its your bodys response to letting you know you need to lay down and rest. the contagious part i am not really sure of.

Answer 3

I saw on some show that it happens when our bodies our transitioning from one phase to another, like being active to resting. It said you didn't have to be sleepy, in fact you could be getting ready to go jogging and start yawning because your body is just preparing for going from inactive to active.

Answer 4

From what I've heard, a yawn actually helps you stay awake by opening your bronchial tubes to allow a greater oxygen flow. As to why it's contagious, I dunno, maybe the idea of a good deep breath is appealing to our subconcious.

Answer 5

I think that yawning is a way to get rid of excess carbon dioxide as well.

Answer 6

When your brain is starved for oxygen, you yawn.

Answer 7

yawns come to you cause your body want more oxegen , and the other is power of suggestion

Answer 8

The same reason we open our mouths to put on mascara.

Answer 9

Good question!!