From "one of the most brilliant young psychologists of her generation" (Paul Bloom), a groundbreaking examination of how speech causes some of our deepest social divides--and how it can help us overcome them. We gravitate toward people like us; it's human nature. Race, class, and gender shape our social identities, and thus who we perceive as "like us" or "not like us". But one overlooked factor can be even more powerful:...