Lots of animals yawn and some even yawn contagiously. Humans, chimps, and dogs, to name a few.
There are many theories as to why we yawn in the first place. Some scientists think it’s a way to cool down the brain; while others think it’s our body’s way of getting extra oxygen. And there are even theories as to why yawning at times appears to be contagious. So far, all scientists can conclude is that it may be a social phenomena linked to empathy–the ability to understand and connect with others’ emotional states.
But the real answer about contagious yawning is this: nobody really knows why. What we do know is that some people are more susceptible to contagious yawns than others, that simply reading the word yawn can make people yawn, and that chances are during the course of reading this post, you’ve yawned at least twice.