Study taps computer to probe why our brains evolved to be so big

NEW YORK – Why do people have such big brains? Some researchers asked a really powerful brain -- a computer -- and got back a surprising answer. In relation to body size, our brains are huge, about six times larger than one would expect from other mammals. And this 3-pound organ sucks up fully 20 percent of the body's energy needs. Evolutionary theory says to build and maintain something that costly, there must have been a very good reason.