Humans aren't alone when it comes to yawning — all vertebrates do it too, including fish, amphibians, reptiles, birds and mammals. But why? The "evolutionarily ancient" act of yawning likely serves a ...

If your head is overheated, there's a good chance you'll yawn soon, according to a new study that found the primary purpose of yawning is to control brain temperature. The finding solves several ...

The most scientifically backed theory about why we yawn is brain temperature regulation. Inhaling air can help cool brain temperature down. Even thinking about yawning can cause you to do it. It’s ...

One of the most common yet enigmatic human actions is yawning. When we're bored, exhausted, or even just notice someone else yawning, we do it. Excessive yawning is usually innocuous, but occasionally ...

Researchers believe the yawning robot may have triggered some biological mechanism in the chimps that they associated with sleep. Image: Popular Science composite, Getty Images/ RMJM, Aline ...

We’ve all been there– sitting in a meeting, reading a book, or daydreaming when someone nearby yawns. Suddenly, you yawn too, almost like a reflex. But why? Is yawning just your body’s way of saying ...