Brain Size: Chimps versus Humans
National Geographic, Feb. 1997, p. 89

As you can see from these pictures, a human's brain is more than three times the size of a chimp's. Why did humans develop large brains? There is a lot of controversy, but most people think that it was either to make tools, or to handle social complexity. Eventually, brains got large enough to do what we do: Think consciously, develop languages, build cities, and even develop tools that tell us what our ancient ancestors were like.

Back to the timeline.


by Robin Stewart