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. 'Modern Tribes' reveals the underlying causes of modern conflict and lights the way forward.
