Social psychologists have long known that human beings often make choices about what to think, and what to do, based on the thoughts and actions of others. Simply stated: We like to follow the crowd. As a psychological phenomenon, it’s called "social proof." And according to Robert Cialdini, the Regents’ Professor of Psychology and Marketing at Arizona State University and Distinguished Professor of Marketing in the W. P. Carey School, "social proof" is one of the six key principles underlying the powerful science of persuasion.

Most people want to give back to people who do something nice for them. In fact, social mores dictate that a favor should be returned in kind, and we apply pejoratives to those who do not: ingrates, moochers. In the second of a six-part series, psychology and marketing Professor Robert Cialdini talks about this phenomenon, which he calls "reciprocity," and examines how the need to repay a kindness can be used to persuade others to agree — or to work — with us.

The ability to persuade others is critical to success, whether you are selling cars or a new corporate strategy. Psychology and marketing Professor Robert Cialdini has examined the component parts of influence, in the lab and on the street. He has learned that persuasion is a science as well as an art. Today, Knowledge@W. P. Carey begins a six-part series that explores Cialdini’s principles of persuasion. The first: the importance of liking the person you are trying to persuade.