Why cooperate? This may be the most important scientific question we have ever, and will ever, face. The science of cooperation tells us not only how we got here, but also where we might end up. Cooperation explains how strands of DNA gave rise to modern-day nation states. It defines our extraordinary ecological success as well as many of the most surprising features of what make us human: not only why we live in families, why we have grandmothers and why women experience the menopause, but also why we become paranoid and jealous, and why we cheat. Nichola Raihani also introduces us to other species who, like us, live and work together. From the pied babblers of the Kalahari to the cleaner fish of the Great Barrier Reef, they happen to be some of the most fascinating and extraordinarily successful species on this planet. What do we have in common with these other species, and what is it that sets us apart? Written at a time of global pandemic, when the challenges and importance of cooperation have never been greater, The Social Instinct is an exhilarating, far-reaching and thought-provoking journey through all life on Earth, with profound insights into what makes us human and how our societies work.