Our brains were designed for tribal life, for getting along with a select group of others (Us), and for fighting off everyone else (Them). But modern life has thrust the world's tribes into a shared space, creating conflicts of interest and clashes of values, along with unprecedented opportunities. As the world shrinks, the moral lines that divide us become more salient and more puzzling. We fight over everything from tax codes to gay marriage to global warming, and we wonder where, if at all, we can find our common ground.A grand synthesis of neuroscience, psychology, and philosophy,Moral Tribesreveals the underlying causes of modern conflict and lights a way forward. Our emotions make us social animals, turning Me into Us. But they also make us tribal animals, turning Us against Them. Our tribal emotions make us fight, sometimes with bombs, sometimes with words, and often with life-and-death stakes. Drawing inspiration from moral philosophy and...