The average adult yawns about 20 times a day.But why? Surely we can’t all be that tired. The truth is, the science behind yawning is more complex than just a few hours too little sleep.

One hypothesis is that contagious yawning evolved to boost threat detection within groups, Gallup told Live Science in an email. In a 2007 study published in the journal Evolutionary Psychology, ...

Everybody yawns, but why? Discover the possible reasons for yawning, why it seems to be so contagious, and if it can ever pose a risk to health.

The science behind yawning and its mysterious behavior 03:38. Humans aren't alone when it comes to yawning — all vertebrates do it too, including fish, amphibians, reptiles, birds and mammals ...

Research shows yawning is extra-contagious when it comes with a sound effect: that “ahhh” noise a lot of us make. So if you hear that over the phone, it might be enough to trigger a ...

Although excessive yawning is usually attributed to being sleepy or bored, it may be a symptom of an underlying medical problem. Learn about the possible causes and treatments.

Does yawning mean our brains aren’t getting enough oxygen? Researchers believe yawning may serve an important physiological purpose. There is no consensus, however, on what that is.

Not everyone is equally susceptible to contagious yawning. In controlled studies, approximately 40% to 60% of typical volunteers yawned in response to watching another person yawn in a video.. A ...

Yawning may help cool down the brain. When temperatures in the brain rise above its baseline — because of increases in mental processing while focusing on a task, exercising or being anxious or ...