It's commonly believed that that grandpa has more knowledge than his young whippersnapper of a grandkid. But do wrinkles on the face really relate to wrinkles on the brain?
WHAT'S INSIDE: INSIDE THE MIND
- The Human Brain
From giggles to guffaws and from chuckles to cackles, we laugh in a lot of different ways -- and what's more, only about 90 percent of our laughter is related to jokes or humor.
If bigger is better, then some of us have the advantage when it comes to brainpower. Human brains (and noggins) don't all look the same. Does size really matter? And if it does, who comes out on top?