Throughout human history, our attitude to the stranger has determined the fate and wellbeing of both nations and individuals. A raft of new science confirms that the more we open ourselves up to encounters with those we don't know, the healthier we are. In this book, with the help of sociologists, psychologists, neuroscientists, theologians, philosophers, political scientists and historians, Joe Keohane learns how we're wired to sometimes fear, distrust and even hate strangers, and discovers what happens to us when we indulge those biases. At the same time, he digs into a growing body of cutting-edge research on the surprising social and psychological benefits that come from talking to strangers; how even passing interactions can enhance empathy, happiness, and cognitive development, ease loneliness and isolation, and root us in the world, deepening our sense of belonging.