We will use the actions of others to decide on proper behavior for ourselves, especially when we view those others as similar to ourselves. - Robert B. Cialdini

Psychologists have long understood the power of the consistency principle to direct human action.

Dear Mother and Dad: Since I left for college I have been remiss in writing and I am sorry for my thoughtlessness in not having written before. I will bring you up to date now, but before you read on, please sit down. You are not to read any further unless you are sitting down, okay? Well, then, I am getting along pretty well now. The skull fracture and the concussion I got when I jumped out the window of my dormitory when it caught on fire shortly after my arrival here is pretty well healed now. I only spent two weeks in the hospital and now I can see almost normally and only get those sick headaches once a day. Fortunately, the fire in the dormitory, and my jump, was witnessed by an attendant at the gas station near the dorm, and he was the one who called the Fire Department and the ambulance. He also visited me in the hospital and since I had nowhere to live because of the burntout dormitory, he was kind enough to invite me to share his apartment with him. It’s really a basement room, but it’s kind of cute. He is a very fine boy and we have fallen deeply in love and are planning to get married. We haven’t got the exact date yet, but it will be before my pregnancy begins to show. Yes, Mother and Dad, I am pregnant. I know how much you are looking forward to being grandparents and I know you will welcome the baby and give it the same love and devotion and tender care you gave me when I was a child. The reason for the delay in our marriage is that my boyfriend has a minor infection which prevents us from passing our pre-marital blood tests and I carelessly caught it from him. Now that I have brought you up to date, I want to tell you that there was no dormitory fire, I did not have a concussion or skull fracture, I was not in the hospital, I am not pregnant, I am not engaged, I am not infected, and there is no boyfriend. However, I am getting a “D” in American History, and an “F” in Chemistry and I want you to see those marks in their proper perspective. Your loving

los investigadores que estudian esta tendencia general a valorar más aquellas entidades ligadas al propio yo (denominada «egoísmo implícito») han averiguado que los sujetos prefieren no solo a las personas, sino también los productos comerciales (galletas, chocolates, tés) cuyos nombres comparten letras con los suyos.