Why Do We Yawn?

Summary: Nobody really knows why we yawn, but like everything else unknown, there are theories about it. What everyone seems to understand is that yawning is involuntary and therefore is like blinking. You can’t really stop doing it, but you can sure try. Some theories say that by increasing the amount of oxygen you take in, you are stretching your muscles. Your body may be unconsciously trying to keep you awake. Another theory is that your body is trying to distribute something called surfactant. This is a slippery substance that you use to – long story short – keep your lungs from collapsing in on themselves, because that, dear reader, would be bad.

Critique: You might think of yawning as annoying, but it’s really not all that bad.
You get used to it. When was the last time you thought about how much you blink or breathe in by yourself? Like how you do it without comprehending, even though blinking temporarily makes the world dark. Isn’t the body amazing?

Impact: No impact, but did you know that yawns are contagious? I bet you yawned just now or during your reading of this article. Nobody can really explain that either, but it’s pretty awesome anyway.

http://kidshealth.org/kid/talk/qa/yawn.html?tracking=K_RelatedArticle