Have you ever wondered why people yawn? What does that large gasp of air physiologically do? Well AsapSCIENCE has an illustrated answer for you.
Unlike snakes that yawn to realign their jaws after a meal, or penguins that use it to woo potential mates, humans yawn to cool their heads. Scientists first thought that humans yawned to get a boost of oxygen to our lungs when tired. However, new research shows that yawning might have more to do with people's brains. Scientists now believe that people yawn to cool their brain down when it gets overheated. Overheating can especially happen if a person is sleep deprived -- hence yawning when exhausted.
But what about the "social" or contagious yawn? Turns out both dogs and primates do it too! Yawning may be contagious due to empathy and mirror neurons. The AsapSCIENCE video below explains: