Dear Reader: We all yawn frequently, more often in the early morning and late evening. Does it mean we’re tired? Bored? Short on oxygen? As common as it is, we know little for certain about yawning.

Seeing or hearing someone yawn can make you yawn. This phenomenon is not limited to humans; some animals experience contagious yawning, too. But why is yawning contagious? Brain cells called mirror ...

Open your mouth wide, stretch the muscles of your jaw and upper body, take a slow breath in, and then exhale quickly. What have you done? You have yawned. Many animals, including humans, yawn. They do ...

Try not to yawn while reading this. (And yes, there's science behind why you yawn when other people do!) Fact checked by Isaac Winter Reviewed by Samina Ahmed Jauregui, PsyD Ever wondered why yawns ...

Ever catch yourself yawning just by reading about it? That’s no coincidence: yawning—stretching your jaw wide, inhaling deeply, then exhaling—is an ancient behavior shared by vertebrates, from fish ...

Ever noticed how one yawn can trigger many? Science reveals how your brain copies others, why yawns spread so easily, and what this curious habit says about humans.