IE 11 is not supported. For an optimal experience visit our site on another browser.

Ho-hum, you’re not dumb: Bigger yawns mean bigger brains, study says

01:02

Scientists say that people with bigger yawns have bigger brains. While yawns are often associated with fatigue or boredom, experts say they bring a rush of blood to the brain, delivering more oxygen and allowing brains to cool off.