Richard Wrangham's 'The Goodness Paradox' addresses a puzzle about human nature: we are simultaneously the least violent species in our daily interactions and the most capable of organized mass killing. Wrangham, a primatologist at Harvard, argues that humans underwent a process of self-domestication that selected for reduced reactive aggression while preserving and even enhancing the capacity for planned, coalitional violence. He traces how this process may have worked, with groups eliminating particularly aggressive individuals through collective execution, gradually producing the docile temperament that allows us to live in close quarters with strangers. The result is a species that is remarkably peaceful in ordinary life but capable of genocide when coalitions mobilize for war. Wrangham draws on evidence from primatology, anthropology, and genetics to develop his argument, comparing humans to other animals that have undergone domestication. The book challenges both optimistic views that see humans as naturally peaceful and pessimistic views that treat violence as inevitable, suggesting instead that we have evolved contradictory tendencies that manifest differently depending on circumstances. Readers interested in human nature, evolution, or the origins of violence will find a provocative and carefully argued theory.