I'll start by explaining the biological phenomenon. Scientists know that yawning is a reflex where air is inhaled and, simultaneously, the eardrums are stretched. Sometimes the rest of the body stretches too. Yawning has been found in humans, animals, and even unborn human babies. The exact cause of yawning is unknown, but scientists have come up with a few theories. The first theory is the theory that yawning occurs when the blood contains too much carbon dioxide and requires a large influx of oxygen to correct this. Another theory is that the muscles of the mouth, jaw and throat feel the spontaneous need to stretch. A third (and extremely popular) theory is that yawning happens when a subject feels boredom or tiredness. Alternatively, you might yawn if you see someone else yawn. Yawning is contagious. Now, I will introduce you the greatest thing since sliced bread: TED-Ed.
The video basically said it best. There are a bunch of theories (both physiological and psychological) about why yawning is contagious. Interestingly enough, we already learned about the debate between John Locke vs. Emmanuel Kant about whether perception is learned or innate. It would seem that the perception of someone else's yawn causing you to yawn is learned. The proof of this is that contagious yawning begins around age four or five, when the child has already developed certain perception features and the mirror neurons are more pruned. However, yawning has also been found in unborn babies in the womb. I think that the yawn itself is a biological instinct for a spontaneous influx of air and for muscle stretching and the contagious yawning is a learned social phenomenon.
Questions (for Rachel) -- Which theory best explains yawning and contagious yawning? Is a combination of theories necessary to fully understand this phenomenon? If so, which theories seem the most plausible to you? What do you think might be the evolutionary benefits of a yawn?
How could I not answer these wonderful questions?
ReplyDeleteI happened to like the Chameleon effect with the mirror neurons, but I also liked the idea that we mimic yawning more when we are among friends.It's probably going to be a combination of a few of those. They're not mutually exclusive.
Ha. Evolutionary benefits of yawning? Weapons against angry enemies? (jokes) Training your kids when to fall asleep?
I started writing about how it's so strange that contagious yawning starts at age 4-5. "We suddenly decided to mimic people when they yawned? You can't make yourself yawn.." I thought. Then I tried making myself yawn, and, well, I yawned. Perhaps once we starting yawning after people it just became a habit, something we didn't have to consciously think about or make ourself do. Whatever the theory, contagious yawning is really interesting.
ReplyDeleteYawn doesn't seem like a word anymore.
All those theories are good. However I think the theory of people yawning to regulate the oxygen level is the best. It doesn't make sense that we yawn because we are tired. What good will yawning do. It does make sense though that there is a correlation between the two of them. If you are tired then your body is not functioning so well. Because of that it could be that your body is doing a poor job of making sure there is enough oxygen in the blood. So you yawn. That would also make sense why its a evolutionary benefit to yawn. You need to yawn to make sure you have enough oxygen.
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