Here it comes. Your mouth gapes open and before you know it, you’re yawning. What’s behind this reflex action?

Researchers from the University of Albany found people yawn more when their brains are warmer. Seems yawning is the body’s way to regulate temperature so the brain can function better.

Before this study, one theory suggested yawning helped the body control oxygen and carbon dioxide levels. But experiments disproved this idea.

Really, no one knows why people (even unborn babies) and animals yawn. Robert Provine, PhD, a neuroscientist, says a yawn is associated with a change in state, such as going from sleep to wakefulness. And even from not wanting to wanting sex!