The Reason We Yawn Might Actually Be To Cool Down Our Brains

Just like the CPU in your computer, the human brain has an optimal temperature where it runs best. But unlike a computer's CPU, there's no built-in fan to chill the brain when it starts to run hot. Which is why researchers now believe that yawning is actually the body's physiological way of keeping the brain nice and… »3/12/14 4:20pm3/12/14 4:20pm