Humans are a puzzling species. On the one hand, we struggle to survive on our own in the wild, often unable to solve basic problems, like obtaining food, building shelters, or avoiding predators. On the other hand, human groups have produced innovative technologies, sophisticated languages, and complex institutions that have permitted us to successfully expand into environments across the globe. What has enabled us to dominate such a vast range of environments, more than any other species? As this book shows, the secret of our success lies not in our innate intelligence, but in our collective brains--in the ability of human groups to socially interconnect and learn from one another. 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 that this particular culture-gene interaction has propelled our species on an extraordinary evolutionary trajectory. Tracking clues from our ancient past to the present, The Secret of Our Success explores how our cultural and social natures produce a collective intelligence that explains both our species' immense success and our human uniqueness.