we yawn because...?

Question

ive yawned even when someone has on tv...

Answer 1

No one knows why we yawn. There are lots of theories, some talk about it signalling tiredness or getting oxygen to the brain, others mention clearing out stale air from the lungs and reducing blood carbon dioxide levels. Most are baloney. But, one thing that is certain, yawns can be infectious. Catch sight of someone yawning and nine times out of ten, you will yawn yourself within a few seconds. Is such an infectious yawn a message to others in the group that it’s time for bed? Probably not, otherwise why yawn first thing on getting out of bed? Either way researchers have found that people with autism spectrum disorder don’t tend to succumb to an infectious yawn.

Atsushi Senju of the Centre for Brain and Cognitive Development at Birkbeck, University of London has shown for the first time that children with some degree of autism are not susceptible to contagious yawning. Autism Spectrum Disorder is a developmental disability that severely affects social interaction and communication including empathy. Report published in the August issue of the Royal Society journal Biology Letters.

This would seem an obvious result given that contagious yawning is thought to share similar cognitive and neural mechanisms as empathy.

Senju and colleagues from the University of Tokyo showed videos of people yawning or making mouth movements to 24 children with autism spectrum disorder and to 25 non-ASD children. Both groups of children yawned the same number of times while watching the video of general mouth movements, but the non-ASD children yawned more when watching the video of people yawning.

“This is the first report that a neuropsychological or psychiatric condition can selectively impair contagious yawning, sparing spontaneous yawning,” explains Senju, “Our study confirms the prediction of ‘empathy theory’, by demonstrating that individuals with autism, who show atypical developments in empathy, also show selective impairment in contagious yawning.”

None of this answers the question of why do we yawn in the first place? Apparently, yawning becomes contagious at around one to two years of age, although unborn fetuses also yawn (presumably not contagiously though!) and can be triggered in animals by stimulating the hypothalamus in the brain with injected dopamine, excitatory amino acids, nitric oxide, and neuropeptides. None of this really explains why we yawn. The empathy angle perhaps points to an ancient benefit in group behaviour, but what that benefit is, science does not yet know.

For more on simple experiments and the power of yawn, check out the neuroscience for kids page at Washington U.

By the way, did you notice while reading this whether you yawned? Hopefully, it was not merely boredom that did it…

Answer 2

The brain needs oxygen because not enough is getting in so it causes the reflex to yawn. When you yawn, the mouth opens letting the oxygen circulate and more to come in. Most people can relate this to being tired because when you are sleeping, your breathing decreases into even breaths and you don't need as much oxygen.

Answer 3

We yawn because when we are tired, our breathing slows down. When our breathing slows down, we do not get enough oxygen to our brain. So, we yawn to compensate for that, getting more oxygen to the brain. So essentially, when you yawn, your body is trying to help you stay awake. We do not yawn due to boredom, as some people think. And as far as yawns being contagious:

"...the Finnish government recently funded a brain scanning study. The results turned up some hard-to-interpret, possible clues. It also confirmed the obvious: yawn contagion is largely unconscious. Wherever it might affect the brain, it bypasses the known brain circuitry for consciously analyzing and mimicking other people’s actions. This circuitry is called the “mirror-neuron system,” because it contains a special type of brain cells, or neurons, that become active both when their owner does something, and when he or she senses someone else doing the same thing. Mirror neurons typically become active when a person consciously imitates an action of someone else, a process associated with learning...wrote the researchers, with the Helsinki University of Technology and the Research Centre Jülich, Germany. The findings are published in the February issue of the research journal Neuroimage."

Answer 4

I must admit I don't buy this 'more oxygen' lark. There are many, many occasions when we require more oxygen - physical exercise springs to mind - when yawning isn't required.
You don't watch the Olympic games and watch the marathon runners nearing the finish line all yawning their heads off - nah, sorry - don't buy that one at all.
The truth is no-one really knows.
My dogs yawn continuously when they are being tickled or having their ears scratched - read into that what you will...
The fact that we do seem to yawn more when we are sleepy does seem to signal that this has at least something to do with it, but oxygen deprivation?
Here - try this - hold your breath for as long as you possibly can... is the first thing you feel when you draw breath a huge urge to yawn?
No.
Didn't think so...
As for it being 'infectious' - humans and chimpanzees are the only two creatures known to yawn just because someone else does.

Answer 5

A yawn (synonyms chasma, pandiculation, oscitation from the Latin verb oscitare, to open the mouth wide ) is a reflex of deep inhalation and exhalation associated with tiredness, stress, over-work, lack of stimulation, or boredom. Pandiculation is the term for the act of stretching and yawning. Yawning is a powerful non-verbal message with several possible meanings, depending on the circumstances. The claim that yawning is caused by lack of oxygen has not been substantiated scientifically. However, the exact causes of yawning are still undetermined.
It may be -
-A means of cooling the brain.
-An action used as an unconscious communication of psychological decompression after a state of high alert.
-A means of expressing powerful emotions like anger, apathy, apprehension, remorse or boredom.
-An excess of carbon dioxide and lack of oxygen in the blood.
-A way of displaying (or indicative of) empathy.
Tiredness



-WIK

Answer 6

That's because are brain thinks that the person yawning is going to take all our oxygen, that's why we yawn for the brain to get more oxygen.

Answer 7

Oxygen deficiency in the brain, yawn causes deep breathing to boost oxygen intake.

Answer 8

We do not yawn just because someone else did it. It basically means your lungs need more air. So when your yawn, your getting that extra air.

Answer 9

people yawn because their either bored or sleepy,if youre watching the tv turn on something else more exciting,we also yawn to refresh ourselves. by getting more air into our lungs.

Answer 10

Its when ur body doesn't get enough oxygen. My substitute teacher told me that in like....3rd grade lol. And i honestly don't know why but yawns are REALLY contageous!!