The results of the famous Stanford Prison Experiment have a trivial explanation.
My own guess is that the behavior of the guards was largely if not entirely the result of their doing what they were told to do and what they believed they were supposed to do. The behavior of the prisoners in the first day or two, when they were pretending to riot and pretending to plot escapes, was probably also playacting of stereotyped concepts of what prisoners do. But their subsequent wearing down, passivity, and apparently genuine desire to get out of the prison may very well have been a direct response to what the guards were doing to them (coupled, I imagine, with their lack of sleep--the guards were on shifts but they were not).
From this point of view, there is nothing in the results of the study that should surprise us. Once we say that the guards humiliated and oppressed the prisoners because they were told to do that and felt it was important to do it for the sake of science, and once we say that the prisoners initially “rioted” because they felt that this is what they were supposed to do but later really did want out because they were humiliated and oppressed, what is there left to be surprised about? Did Zimbardo and his colleagues really need to do this experiment to “prove” such an obvious result? And does this really tell about the behavior of real guards and prisoners, who are not there for a two-week experiment (for the good of science), but are there because that is how they make their living or because they are being punished for a crime? There is no way to simulate the real experiences of being a guard or a prisoner.
Too often, in our psychological research labs, we trivialize reality. Zimbardo’s prison experiment is a good example of that. If I had included Zimbardo’s experiment in my textbook, it would have been to make that point.