The human body is a wondrous yet perplexing machine that can spur lots of interesting questions. Here’s a great one.
Why are yawns contagious?
Have you ever yawned in front of someone, only to have them yawn right back?
It’s a common phenomenon, but researchers don’t have a conclusive explanation for it. They do know, however, that this happens only with humans and chimpanzees.
A bigger question puzzling scientists is why we yawn at all. It used to be thought that yawning indicated a lack of oxygen to the brain, but that’s just a myth. A growing body of research now suggests that yawning is nature’s way of keeping our brains cool.