Why is yawning contagious?

I have heard that it is actually caused by the brains sub-conscious attempt to fit in, but I will be interested in learning what others have to say.

From we no know yet.

I’ve heard that when the brain tires, yawning is a way to refresh it with a larger than usual oxygen supply. My un-substantiated theory is that when we observe that our brains think “hey, good idea” and stimulate our body into doing the same.

I don’t know, but it is fun to do when you are walking back to your seat on an aircraft. By the time you sit down half the passengers are yawning.

I remember a couple of years back, I was taking a standardized test (I can’t remember if it was the MCAS or the PSAT, but I digress), and there was a question about yawning. Everyone in the classroom taking the test started yawning uncontrollably for the entire duration of the test.

p.s. @dpworkin Be nice. Obviously English isn’t his first language.

I heard it was because when you see another person yawn, it reminds your brain to check if you have enough air, so you yawn.

I’m not nice. Suck it up.

It is a matter of very active inquiry. Gordon Gallup and his group at SUNY Albany have an hypothesis (which I think is crap) that it has to do with cooling a hyperthermic brain. They actually have written a protocol for an experiment, but they haven’t collected any data yet.

At any rate, nobody knows, and everyone wants to find out. Canine behaviorists note that dogs yawn to dissipate anxiety, and some evolutionary psychologists think that for that reason it may have had a derived social function in Homo to release social tension.

Any reasons people give at this point in time are merely theories. No one knows why we yawn, why it is contagious, or even why it’s contagious cross-species.

short to answer to @betoalvo: mirror neurons. Google it.

@MissAnthrope But it’s fun to come up with theories…

@cockswain – I wholeheartedly agree. :)

I was looking for an email forward I got eons ago, where a professor asked students this question and one of them replied that when one person yawned, it created an air pressure disturbance, which then caused other people to yawn to accomodate the change in pressure. I always liked that answer and kind of wish it was true.

Anyway, in searching for that, I found this article suggesting that we yawn to cool our brains down and there’s another article that.says how cool our brains are will affect our susceptibility to catching someone else’s yawn.

I have perfected the art of yawning with my mouth closed (to prevent socially inappropriate yawning), but my technique involves breathing in a lot of air through my nose and then back out. So the brain-cooling thing jives, considering nose-breathers have a lower incidence of catching yawns (as well as people with cool packs on their foreheads).

I can make my sister yawn over the PHONE!

I doon’t knooow