At least one-third of the people we know are introverts. They are the ones who prefer listening to speaking, reading to partying; who innovate and create but dislike self-promotion; who favor working independently over brainstorming in teams. Although they are often labeled "quiet," it is to introverts that we owe many of the great contributions to society--from van Gogh's sunflowers to the invention of the personal computer. The dominant values of American business culture, where forced collaboration can stand in the way of innovation, and where the leadership potential of introverts is often overlooked. Quiet shows how dramatically we undervalue introverts, and how much we lose in doing so.