Martin Nowak, one of the world’s experts on evolution and game theory, working here with bestselling science writer Roger Highfield, turns an important aspect of evolutionary theory on its head to explain why cooperation, not competition, has always been the key to the evolution of complexity. In his first book written for a wide audience, this hugely influential scientist explains his cutting-edge research into the mysteries of cooperation, from the rise of multicellular life to Good Samaritans, and from cancer treatment to the success of large companies. With wit and clarity, and an eye to its huge implications, Nowak and Highfield make the case that cooperation, not competition, is the defining human trait. will expand our understanding of evolution and provoke debate for years to come.