Title says it basically.
I was reading on this randomly and saw that scientists don't know why something this basic occurs.
| Quote: |
We know that yawning appeared early in vertebrate history and that and most other animals with backbones, including fish, turtles, birds, and crocodiles, engage it. But we don’t know why it appeared. [...] People begin to yawn early in their lives. Indeed, yawning has been observed in three-month-old fetuses — evolutionary evidence of how ancient the behavior is. It’s the contagious quality of the activity that’s especially intriguing. [...]
“Contagious yawning definitely does not involve a conscious desire to replicate the observed act,” Provine observes, but it’s possible, as some research into brain activity suggests, that someone who “catches” a yawn may be unconsciously expressing “a primal form of empathy.” Thus, contagious yawning can be linked to sociality. Some neurological and psychiatric disorders, such as schizophrenia and autism, that leave patients “deficient in their ability to infer or empathize with what others want,” apparently reduce as well their susceptibility to contagious yawning. |
http://atheism.about.com/b/2006/02/14/why-do-people-yawn.htm
I thought it was pretty interesting. Nothing incredibly groundbreaking lol, but neat nonetheless, specifically the hypothesis that it is a form of empathy.
Not really sure if there's a discussion here 
Just thought I'd throw some random information out there. I have a heart of stone so don't think that my catching a yawn is in any form, me empathising.
I'm fairly confident that it is all in the head (as so many things are) but have no other explanation for anything after that.
It will be interesting to hear if anyone else knows about any research into this. I'd love to be able to avoid a contagious yawn, yet at the same time, make mine even more so One reason for the contagiousness is rapport. If you pay attention you can often catch people copying each other in many ways, including yawning. This happens especially if they are talking to each other or in a close relationship with each other. Doing so builds a sense of empathy with the other people. If you pay attention to signals like this, it can help figure out relationships between people because nearly all of them do it without thinking about it.
Mythbusters actually did an episode that was built around the idea of yawning being contagious.
I have read somewhere (can't remember where or when 
) that yawing is not caused by tiredness itself, but by the lack of oxygen in the blood stream. This in itself I know is a cause of tiredness, as is the lack of sugars in the blood stream. Therefore in an attempt to increase the bodies oxygen the body triggers a long deep breath (yawn) and with the longer and bigger breath comes the necessary increase in oxgen in the lungs and thencs blood stream, | WhistleTurning wrote: |
| I have read somewhere (can't remember where or when ) that yawing is not caused by tiredness itself, but by the lack of oxygen in the blood stream. This in itself I know is a cause of tiredness, as is the lack of sugars in the blood stream. Therefore in an attempt to increase the bodies oxygen the body triggers a long deep breath (yawn) and with the longer and bigger breath comes the necessary increase in oxgen in the lungs and thencs blood stream, |
Pretty sure that's true That's what I've always heard as well. I thought the explanation of the "contagiousness" was interesting though.yawning can be caused by an oxygen sortage, you yawn to get more oxygen inside of you. So next time when someone is yawning it is good, because he needs more oxygen to think so that he can concentrate more on you.
I heard that when your intestines make noise because you are hungry or by some other reason, that noise is contagious too. So when you hear that noise in someone else, your own intestines can begin to make noise too.
| Insanity wrote: |
| Mythbusters actually did an episode that was built around the idea of yawning being contagious. |
The record clearly shows that questionable facts on the internet are a lot more questionable than yawning. On the mythbusters show, there did appear to be some "contagious" yawning. But their analysis showed the effect, if it exists, producing only a slight preference for yawning, not enough to mean anything statistically.
Mythbusters called the myth "plausible". That seems reasonable enough to me, since they were not able to either confirm or bust the myth. Yet references on the internet include some saying they "busted" the myth, and others saying they confirmed it. Conclusion: use more salt when checking things on the internet. | SonLight wrote: |
| Insanity wrote: | | Mythbusters actually did an episode that was built around the idea of yawning being contagious. |
The record clearly shows that questionable facts on the internet are a lot more questionable than yawning. On the mythbusters show, there did appear to be some "contagious" yawning. But their analysis showed the effect, if it exists, producing only a slight preference for yawning, not enough to mean anything statistically.
Mythbusters called the myth "plausible". That seems reasonable enough to me, since they were not able to either confirm or bust the myth. Yet references on the internet include some saying they "busted" the myth, and others saying they confirmed it. Conclusion: use more salt when checking things on the internet. |
Obviously these are all hypotheses. Nobody is saying anything with 100% certainty. | ocalhoun wrote: |
| One reason for the contagiousness is rapport. If you pay attention you can often catch people copying each other in many ways, including yawning. This happens especially if they are talking to each other or in a close relationship with each other. Doing so builds a sense of empathy with the other people. If you pay attention to signals like this, it can help figure out relationships between people because nearly all of them do it without thinking about it. |
I think thats the main reason for yawning being contagious. You can try a little experiment to confirm how all kinds of behaviour are contagious. For example, scratch your head when your talking to someone. A lot of times they will do the same a few seconds later. Or suddenly change the way you sit: if you are both leaning forward and you change to leaning backward your partner will probably to the same.
The reason people notice this mostly with yawning is because it is so apparent. Scratching your head, coughing, taking a sip of your drink, etc. doesn't attract much attantion.
I once read in a popular-scientific magazine that only hunting animals yawn (because of the blood-to-brains mechanism people already explained here). But this doesn't seem right to me. For example, don't horses yawn too? | MrBlueSky wrote: |
| don't horses yawn too? |
| Quote: |
| About the only thing we're fairly sure of is that the trigger is not the same as that of a yawn in humans, which is in response to transient drops in blood oxygen levels. That big intake of fresh air increases oxygen in the lungs and therefore in the vascular system. However, horses do not appear to be inhaling when they "yawn." |
Apparently, that is a question that depends on just how you define a yawn. Horses don't breathe through their mouths anyway. Come to think of it, researching horses' yawns could lead to insights about why humans yawn for exactly that reason...I saw it on brainiac if you yawn people who like you will yawn aswell...
I also tested it and it did work so i supose its true...
| ocalhoun wrote: |
Apparently, that is a question that depends on just how you define a yawn. Horses don't breathe through their mouths anyway. Come to think of it, researching horses' yawns could lead to insights about why humans yawn for exactly that reason... |
Maybe horses yawn to communicate. Or just to stretch their jaw muscles..An episode of Myhbusters confirmed that it is contagious.
It has something to do with so called mirror neurons, that trigger the same process in the brain as somebody has when we watch him doing something. If it is not blocked (as it is usually on a farther down level) we do the same thing as somebody we watch -> contagious
