Robert Cialdini

Robert Cialdini built his science by doing something no academic psychologist had done before: he went into the field. In the 1970s, dissatisfied with laboratory studies that told him how college students behaved under fluorescent light, he trained alongside encyclopedia salespeople, car dealers, and fundraisers to learn the working knowledge of the people he came to call compliance professionals. What he found was not a thousand tricks but a small set of deep regularities—six principles that recur because they are wired into how human beings decide under the pressure of too much information and too little time. Reciprocity, commitment and consistency, social proof, authority, liking, scarcity: each is a lever, and each works because it is usually a sensible shortcut, a way of deciding well without deliberating endlessly. That is the point most often missed about Cialdini’s contribution: these are not flaws in human cognition but features of it, evolved adaptations to