This is an enhanced edition of the HBR reprint R0109D, originally published in September 2001. HBR OnPoint articles save you time by enhancing an original Harvard Business Review article with an overview that draws out the main points and an annotated bibliography that points you to related resources. This enables you to scan, absorb, and share the management insights with others. If leadership, at its most basic, consists of getting things done through others, then persuasion is one of the leader's essential tools. Over the past several decades, experimental psychologists have learned which methods reliably lead people to concede, comply, or change. Their research shows that persuasion is governed by several principles that can be taught and applied. The first principle is that people are more likely to follow someone who is similar to them than someone who is not. Second, people are more willing to cooperate with those who are not only like them but who like them, as well. Third, experiments confirm the intuitive truth that people tend to treat you the way you treat them. Fourth, individuals are more likely to keep promises they make voluntarily and explicitly. Fifth, studies show that people really do defer to experts. Finally, people want more of a commodity when it's scarce; it follows, then, that exclusive information is more persuasive than widely available data.