Drawing insights from lost European explorers, clever chimpanzees, hunter- gatherers, neuroscientists, ancient bones, and the human genome, Joseph Henrich demonstrates how our collective brains have propelled our species' genetic evolution and shaped our biology. Our early capacities for learning from others produced many innovations, such as fire, cooking, water containers, plant knowledge, and projectile weapons, which in turn drove the expansion of our brains and altered our physiology, anatomy, and psychology in crucial ways. Further on, some collective brains generated and recombined powerful concepts, such as the lever, wheel, screw, and writing. Henrich shows how our genetics and biology are inextricably interwoven with cultural evolution, and