brain size

Why do humans have such large brains? Our study suggests ecology was the driving force

Why do humans have such large brains? Our study suggests ecology was the driving force

Most animals have brains in proportion to their body size – species with larger bodies often have larger brains. But the human brain is almost six times bigger than expected for our bodies. This is puzzling, as the brain is very costly – burning 20% of the body’s energy while accounting for only 4% of its mass.