Why Are Yawns Contagious?

Why is yawning contagious?

Why do we yawn when we see babies yawn? The phenomenon is called contagious yawning,and it's very odd indeed.

Dogs yawn…and cats and monkeys…and even three-month-old fetuses (but not chickens). An average yawn lasts four to six seconds. We yawn more when we’re tired or bored. And trying to make it stop usually just makes another yawn pop right out. But surprisingly, we have no idea why we yawn. It’s a big medical mystery.