Why Do We Yawn? [Video]

Last week I told you about this study that shows how yawning is linked to love, but why do we yawn?

Lacking oxygen? Mating call? Nope!

How about cooling your brain?

Yup! At least that's what scientists are starting to think.

So you may be thinking, then why do I yawn when I'm tired?

Well, the brain heats up when you're exhausted or sleep deprived.

No lie, it's so contagious that I yawned 4 times while writing this.

Now go show off your new yawn knowledge

***yawn***