We all know people who talk with their hands—but do they know what they’re saying with them? Our gestures can reveal and contradict us and express thoughts we may not even know we’re thinking. In Thinking with Your Hands, esteemed cognitive psychologist Susan Goldin-Meadow argues that gesture is vital to how we think, learn, and communicate. She shows us, for instance, how the height of our gestures can reveal unconscious bias or how the shape of a student’s gestures can track their mastery of a new concept—even when they’re still giving wrong answers. She compels us to rethink everything from how we set child-development milestones to what’s admissible in a court of law to whether Zoom is an adequate substitute for in-person conversation. Sweeping and ambitious, Thinking with Your Hands promises to transform the way we think about language and communication.