Big Brains Throw Rocks Good
Discover tells us why our brains got big:
Why did hominin brains triple in size over the past 6 million years?
William Calvin, a neurobiologist at the University of Washington in Seattle, argues that it all has to do with throwing a rock. To hit the target, the brain had to coordinate such variables as muscle movements, visual images, and the weight of the stone. Only an increase in brain size could make throwing—especially over long distances—accurate, he says. That neural circuitry was able to handle other complex matters: keeping track of social relationships, planning for the future, and developing language.
But just so you don't get cocky, you should know that they're not as big as they used to be...
via BoingBoing