According to Google's English Dictionary, the action of nudging is to “prod (somebody) gently with one's elbow to attract attention” or “to coax or gently encourage (someone) to do something”. In everyday life nudging is thus synonymous with genteel actions of social notification and encouragement. Although gentle, and often innocuous, nudging is actually a powerful way to exert social influence. In his influential 1936 book How to Win Friends and Influence People, Dale Carnegie reveals the operational logics and power of social nudges. According to Carnegie, the key to long-term social influence is not to be found in aggressive coercion but in a deep understanding of human nature and interpersonal relations. Carnegie's central insight was that all people want to feel important. So, the key to lasting social influence was not to force people into behaving in certain ways, but to make them feel significant and valued. Carnegie advocated a series of genteel actions to promote change in others: showing sincere appreciation towards other people; demonstrating an interest in the needs and desires of others; recognizing your own mistakes before drawing people's attention to their own errors; constructing reputations for people that they will want to live up to; and even doing something as simple as remembering other people's names. There was no science behind Carnegie's insights. His philosophy of gentle social influence was derived from his experience as a salesman and public speaker. Carnegie did not use the term nudging to describe his techniques. However, as we shall see, his ideas reflect early iterations of the practices of nudging that we aim to explore in this book.

Few of us enjoy forcing people to do things. The appeal of Carnegie's insights lie in the fact that they suggest that subtle persuasion is both a more socially agreeable and often more effective way to shape the behaviours of those around us than coercion. In addition to their effectiveness, the forms of subtle persuasion promoted by Carnegie carry with them a kind of moral virtue. They suggest that one of the best ways of achieving our goals may be found in being nice to others.