Influence: The Psychology of Persuasion

by Robert B. Cialdini

training participants to focus on the true credentials of a spokesperson in an ad did, in fact, make them better evaluators of ads they experienced much later. They became not only less persuaded by subsequent ads featuring spokespeople with no relevant credentials (an actor, Arnold Schwarzenegger, promoting a type of internet technology, and a game-show host, Alex Trebek, touting the health properties of milk) but also more persuaded by spokespeople with relevant credentials (an MD director of a pain institute, recommending a pain reliever, and a CEO, describing his company’s years of good experience with a brand of business insurance). The lesson? To defend ourselves against misleading appeals containing ersatz authorities, we should always ask, Is this authority truly an expert? We shouldn’t presume we are too smart to be tricked by mere symbols of authority. Those symbols operate automatically on us. In my team’s research, it was only the participants who, recognizing their susceptibility to this automatic process, were able to disrupt it by questioning communicators’ relevant expertise. And it was only those participants who weren’t fooled.