Why do we yawn and why is it contagious?

Question

My answer to this question would have been:-

Part1

"It was long believed that yawning was an involuntary reflex meant to draw more oxygen into the bloodstream and remove a build-up of carbon dioxide.

This theory is based on the idea that when people are bored or tired their breathing slows down, resulting in a lack of oxygen, which causes them to yawn.

However research has found this isn't the case. It has also been found that fetuses yawn in the womb even though they don't breathe oxygen into their lungs until after birth.

Other theories are that yawning regulates body temperature or that it's caused by changes in certain chemicals in the brain. It's now accepted that the exact reasons we yawn are unknown.

cont.....part 2.

My answer to this question would have been:-

Part2

It's also not known why yawning is contagious. One theory is that we've evolved to yawn when others around us do because our early ancestors used yawning to co-ordinate social behaviour or build rapport in a group. When one person yawned to signal something, such as it being time to sleep, the rest of the group yawned in agreement.

This has carried through to the present where it seems the suggestive power of yawning is still contagious. Lending weight to this theory is the fact that babies, who're unaware of social codes, don't yawn contagiously until they're about one year old.

Answer 1

There is not a clear answer yet of why we yawn (and anyone that says they know for sure is lying, there is no research that conclusively states why we yawn.) However here are the best hypothesis why and why it's contagious. First why it's contagious. We don't exactly know why it's contagious but we know it is. Some think that it goes back to the primate days and that it was a signal to the rest of the group that they were going to be doing a new activity or to coordinate some type of social behavior. But now for us it just a left over behaviour that we no longer use.

Some hypothesis of why we yawn are...Dr. Provine suggests that perhaps yawning is like stretching. Yawning and stretching increase blood pressure and heart rate and also flex muscles and joints. Evidence that yawning and stretching may be related comes from the observation that if you try to stifle or prevent a yawn by clenching your jaws shut, the yawn is somewhat "unsatisfying." For some reason, the stretching of jaw and face muscles is necessary for a good yawn.

The same doctor also showed that we do not yawn to get rid of excess CO2 or to get more O2. If this was true then people who are running low on oxygen or high on CO2 would yawn more often then those who don't and this wasn't the case.

Another reason why some think that we yawn is to signal to our brains a change in activity. We normally yawn right when we get out of bed or right before we go to bed. We yawn through a boring lecture in the hopes of changing the activity. Siamese fighting fish yawn before attacking. Lions wolves and primates yawn about 45 minutes before eating. But in answer to your questions we really don't know for sure

Answer 2

We yawn when we need more oxygen going to our brain. When you're tired or bored you're breathing can become irregular causing a lack of oxygen in the bloodstream. It isn't simply a 'joke' that yawning is contagious, it is the effect of evolution. If we see someone doing something that is in a sense healthy or good for them in some way, there is an innate tendancy to do the same. Someone laughs, we laugh, someone smiles, we smile. It's a lot more complicated than that, but I think you get what I'm saying.

Answer 3

When your body is asleep, it requires a lot less oxygen, and your breathing slows down a lot. When you're tired, your body starts slowing down like it would if it were going to sleep. When you yawn, you're usually tired, but trying to stay awake. So your body forces you to do something to give it more oxygen (the yawn) so it can keep going and stay awake.

Yawns aren't contagious. I think when someone sees someone else yawn they decide they're tired too and just join in. Haha

Answer 4

We yawn because we are not getting enough oxygen; and a yawn forces a massive intake of it. We don't get enough oxygen because when we are tired we slump and or take shallow breaths. It isn't contagious but the power of persuasion subconsciously reveals to other people that they need more oxygen as well.

Answer 5

The biological reason that we yawn is hard to pinpoint it could be many things, however, the "contagious" aspect is basically just that psychologically when one person yawns, others tend to do the same thing. The same reason why if you are with somebody and you scratch your head they will probably do the same thing. Try it for yourself next time you are talking to somebody just put your hand on your chin and see if they do the same or even raise your eyebrows and see if they raise theirs. It probably has something to do with conforming, or trying to make the people you are with feel comfortable subconsiously.

Answer 6

Our bodies induce yawning to drawn in more oxygen or remove a build-up of carbon dioxide. That is the age old question, nobody really knows why its contagious.

Answer 7

Our bodies induce yawning to drawn in more oxygen or remove a build-up of carbon dioxide. This theory helps explain why we yawn in groups. Larger groups produce more carbon dioxide, which means our bodies would act to draw in more oxygen and get rid of the excess carbon dioxide.

Answer 8

The intent we yawn is due to the fact our respiring slows inflicting a loss of oxygen and so we yawn to absorb a deep breath, that is why we yawn after we are worn out-our respiring slows down. And after we see any one else yawn our respiring slows down relatively once more so we yawn :)

Answer 9

It's not contagious and your brain doesn't need more oxygen it's an automatic reaction it's actually your brain mimicking someone else yawning

Answer 10

It's all a mystery. Scientists still don't know why people yawn. They used to say it was because we were sleepy or bored or because there wasn't enough oxygen going to our brains, but that's not true.