If we refer to criticism we have to take in count that it practice the judging of something or someone. When a new major discover is released or an event of great magnitude occurs it is expected to be criticized in many aspects.

We can see this on the social psychology experiment of Phillip Zimbardo Stanford Prison Experiment (SPE) of 1971 when the results and conclusions from the experimenters were released to the public it was only matter of time for criticism to invade it causing controversy over both scientific and ethic rigors.

One of the main critics to this experiment was that the experimental evaluation applied to the study by the experimenters brought subjective and anecdotal conclusions. The experiment didn’t follow a scientific method. Also the fact that participants were meticulously selected, by being psychologically tested and were chosen from a group of men students of similar age make the experiment impossible to be replicated to the rest of society, causing the lack of generalizability. Based on these arguments several critics said it was more of a demonstration than a scientific experiment to which Zimbardo defend himself by saying on the Toronto Symposium of 1996 the following statement:

I hereby assert that none of these criticisms present any substantial evidence that alters the SPE’s main conclusion concerning the importance of understanding how systemic and situational forces can operate to influence individual behavior in negative or positive directions, often without our personal awareness. The SPE’s core message is not that a psychological simulation of prison life is the same as the real thing, or that prisoners and guards always or even usually behave the way that they did in the SPE. Rather, the SPE serves as a cautionary tale of what might happen to any of us if we underestimate the extent to which the power of social roles and external pressures can influence our actions-

Critics about the ‘demand of characteristic’ were also made to the SPE. They argued that participants in psychological experiments are more likely to do what they believe the researchers want them to do, in other words, critics argued that participants were acting. In fact there is one statement that was given by one of the subjects who played as a guard during the experiment that support this criticism.

After this statement was told, Zimbardo wrote that actions from that student specific had gone ‘far beyond simply playing the role of a tough guard’, and that his and the other guards’ acts, ‘tell us something important about human nature’.

In the other hand moral and ethical aspects were also highly criticized, they were actually the ones who caused more polemic. Students who played as prisoners were, stripped from their identity of who they are from the outside world, and they also were emotionally and psychological traumatized. Meanwhile, the students who played the guards were judged to have exhibited ‘genuine sadistic tendencies’ that were acquired by the role they were ask to interpret. Even Zimbardo himself become deeply absorb in his role of superintendent. -I began to talk, walk, an act like a rigid institutional authority figure more concerned about the security of ‘my prison’ than the needs of the young men entrusted to my care as a psychological researcher. In a sense, I consider the extent to which I was transformed to the most profound measure of the power of the situation – Zimbardo (2004), this conduct make him unable to control or act by his experimenter role and be aware of the health of the subjects.

This ethical concerns surrounding the experiment were consider as an abuse and mistreat to the mental and also physical (mostly of prisoners) health of the students involved, breaking like this all the ethical principles of a scientific experiment. The American Psychological Association (APA), which considers a wide range of ethical issues, including those related to research procedures and practices stipulates that researchers are obligated to guard the rights and welfare of all those who participate in their studies, fact that wasn’t applied in this experiment.

Despite of the negative critics, the SPE is rightly recognized as a classic study in social psychology because of the strongly testimony of the capacity for people who have reasonable claim to be consider normal, decent and civilized to present contradictory behavior during an specific situation. Also one positive impact of the study is that it has altered the way US prisons are run. For example, juveniles accused of federal crimes are no longer housed before trial with adult prisoners, due to the risk of violence against them. Zimbardo’s experiment became worldwide recognize, and films and documentaries about the study has being made since then.