The good folks over at superscholar sent me this fascinating infograph, showing how our brains have actually been shrinking over the past 10,000 years. Enjoy.

(click for bigger image)

Given this decreasing brain size doesn’t result in a reduced EQ I suspect the answer may have something to do with the fact that our brains are very expensive, requiring 20% of our daily caloric intake. Any steps evolution can take to reduce the energy used by the brain but still retain the benefits of having a high EQ would be highly beneficial.