Why do we yawn?

Question

i have heard that we yawn due to lack of oxygen to the brain.i cant quite understand this because we yawn when we are really bored.what is the connection?

Answer 1

i dunno .... sometimes without even knowing it we yawn because we see people yawn. Have you ever tried yawning in public in front of someone..........see if other people around you start yawning too.....its a conspircy that scientist can't explain

Answer 2

Very interesting question...

I've heard that it has to do with the oxygen too, but that's usually when a room is stuffy and closed for a long time, and we start to feel drowzy, yes?

Although think of the times when someone else yawns and then we yawn too, so it must not be only with oxygen.

Answer 3

Well, I heard from the news and from my mum that we yawn it's cause we need oxygen. Our brain lacks it when we wake up ( cause we take seriously slow breath while we sleep ) And also, since you yawn when you wake up since a baby ( and most probably you still have a tired feeling when you wake up ), it sorta becomes a habit to you.

You feel tired, you yawn, though your brain don't need to oxygen whatsoever.

And also, when we see people yawning we yawn, it's kinda a natural reaction in humans. When we see some people doing some things, we would want to try it ourselves. So it kinda activates our yawning when we see someone else yawns. =P

Hope this helps and this are all based on my thoughts only. =)

Answer 4

Thats what I have been taught too. I never figured it out either.
The link below gives some interesting facts about yawning;

Answer 5

I've heard that it's not about needing oxygen. I've also heard that from a scientifically proven standpoint, no one knows why we yawn, why we do it when we do, or why it's contagious. I don't know if those things are true, just what I've heard.

PS, you have me yawning now.

Answer 6

i think its the body's way of catching up to what it needs at that particular time.Like leap year is the way us humans put in calendars every 4 years because we lose a little time.another words there are not actual 24 hours in a day there are really 23 hours and 56 minutes in a day but that would be awkward

Answer 7

its probably cos when there's less oxygen in ur brain you get bored...cos you're not able to grasp whats going on...you have no interest.
but yes it has to do with oxygen levels

Answer 8

No one is exactly sure why we yawn.

See http://en.wikipedia.org/wiki/Yawning

Answer 9

boredom and tiredness