«Y han tenido ustedes, y pueden haberlos tenido, a príncipes más valerosos y sabios aquí sentados, aunque nunca han tenido, ni tendrán, a uno que los… - Robert B. Cialdini

In one experiment conducted on five classes of Australian college students, a man was introduced as a visitor from Cambridge University in England. However, his status at Cambridge was represented differently in each of the classes. To one class, he was presented as a student; to a second class, a demonstrator; to another, a lecturer; to yet another, a senior lecturer; to a fifth, a professor. After he left the room, each class was asked to estimate his height. It was found that with each increase in status, the same man grew in perceived height by an average of a half inch, so that as the “professor” he was seen as two and a half inches taller than as the “student.

Consider the results of a study conducted at Northwestern University. Researchers gave online participants information about a pair of sofas we’ll call the Dream and the Titan. The two, manufactured by different furniture companies, were comparable in all respects except for their cushions. The Dream’s cushions were softer and more comfortable than the Titan’s but less durable.

This parallel form of human automatic action is aptly demonstrated in an experiment by Harvard social psychologist Ellen Langer. A well-known principle of human behavior says that when we ask someone to do us a favor we will be more successful if we provide a reason. People simply like to have reasons for what they do. Langer demonstrated this unsurprising fact by asking a small favor of people waiting in line to use a library copying machine: Excuse me, I have five pages. May I use the Xerox machine because I’m in a rush? The effectiveness of this request-plus-reason was nearly total: Ninety-four percent of those asked let her skip ahead of them in line. Compare this success rate to the results when she made the request only: Excuse me, I have five pages. May I use the Xerox machine? Under those circumstances, only 60 percent of those asked complied.