Part 2

CONCLUSIONS: An extremely high level of conformity was observed of ‘guards’ and ‘prisoners’ to their roles.

However, many participants reported afterwards that they had acted ‘out of character’.

Personality tests indicated no significant differences between the guards’ and prisoners’ personalities which supports a situationalist rather than dispositionalist explanation of conformity resulting in extreme and/or callous behaviour towards others. Zimbardo believed that the study demonstrated the powerful effect social roles can have on peoples’ behaviour. Basically the participants were playing the role that they thought was expected of either a prisoner or prison guard. (Effectively a simulation of what prison life was thought to be, rather than what it was, as none of the participants had previously been in prison as a guard or prisoner).

Zimbardo explained that the reason for the deterioration in guard behaviour was power. The guards were given control over the lives of other human beings and did not have to justify their displays of power as they would normally have to in their daily lives. They started

to enjoy this power very earlier on in the study (‘pathology of power’) as demonstrated that even after the first day all prisoner rights

Kim Duke’s documentary of the Stanford Prison Experiment Experiment - copyright © 2002 BBC

became redefined as privileges and all privileges were cancelled.

Zimbardo explained the social deterioration of the prisoners as the ‘pathological prisoner syndrome’. At the beginning of the study, the prisoners rebelled against their conditions, but the guards undermined every attempt at rebellion, and any solidarity between the prisoners collapsed. Half of the prisoners responded by becoming ‘sick’ and eventually had to be released before the study was finally brought to a conclusion. The remaining prisoners became passive, dependent and had flattened emotions. Zimbardo suggested that there were a number of processes that contributed to the pathological prisoner syndrome:-

• The loss of personal identity – the prisoners were deindividuated by being stripped of their individuality, their name, dress, appearance, behaviour style, and history and then made to live among strangers who do not know their name or history
• The arbitrary control exercised by the guards - on post-experimental questionnaires, the prisoners said they disliked the way that the way they were subjected to the arbitrary and changeable decisions and rules of the guards as this made life unpredictable and unfair. (For example, smiling at a joke could be punished in the same way that failing to smile might be.) As the environment became more unpredictable, the prisoners’ behaviour showed signs of learned helplessness - ie as the prisoners’ previously learned assumptions about a just and orderly world were no longer functional, they ceased to initiate any action
• Dependency and emasculation - the prisoners were made to be totally dependent on the guards for commonplace functions such as going to the toilet, reading, lighting a cigarette and this emasculated them - a sense exacerbated by not wearing any underwear. This was reflected in the bizarre fact that, when the prisoners were debriefed, they suggested that they had been assigned to be prisoners because they were smaller than the guards - in fact there was no difference in average height between the prisoners and guards; and the perceived difference appeared to be a response to the

prisoners’ perception of themselves and their lack of power.

CRITICISMS (EVALUATION): Most criticisms of Zimbardo’s study are on ethical issues:-

• Zimbardo deceived the ‘prisoner’ participants, with their arrest at the beginning of the experiment. They were not told partly because final approval from the police wasn’t given until minutes before the arrests were due to begin and partly because the researchers wanted the arrests to come as a surprise. However this was a breach of the ethics of Zimbardo’s own contract that all of the participants had signed.
• It was not ethically acceptable to expose people to such degradation and hostility even with their fully-informed consent.
• Zimbardo being both ‘superintendent’ and chief researcher produced a conflict of roles whereby he lost sight of the harm being done to the participants
• Those who had been guards had to face up to the disconcerting fact that they had been willing to mistreat their prisoners. Guard ‘A’ said in debrief: “I was surprised at myself - I made them call each other names and clean the toilets out with their bare hands. I practically considered the prisoners cattle and I kept thinking I have to watch out for them in case they try something.”

In Zimbardo’s defence, it needs to be said that:-

• When he realised just how much the prisoners were suffering, which was unexpected, the experiment was abandoned.
• Approval for the study was given from the US Office of Naval Research and Stanford University’s Psychology Department and the University Committee of Human Experimentation - the Committee also did not anticipate the prisoners’ extreme reactions that were to follow
• Alternative methodologies were looked at which would cause less distress to the participants and at the same time give the desired information, but nothing suitable could be found
• Extensive group and individual debriefing sessions were held, in which the moral conflicts  posed by the study were discussed, and all participants returned post-experimental questionnaires several weeks, then several months later, then at yearly intervals  
• Zimbardo also strongly argued that the benefits gained about the understanding of human behaviour and how society can be improved should out-balance the distress caused by the study. However it has been suggested that the US Navy was not so much interested in making prisons more humane and were, in fact, more interested in using the study to train people in the armed services to cope with the stresses of captivity

There were also a number of validity issues to do with the study:-

• The artificial set-up may have facilitated demand characteristics - with the ‘guards’ and ‘prisoners’ play-acting, rather than genuinely conforming to their roles, as Ali Banuazizi & Siamak Movahedi (1973) argued. (The most callous ‘guard’, who later revealed himself to be Dave Eshleman, was dubbed ‘John Wayne’ by the others for his macho attitude. He admitted in debriefing to having recently watched the movie, ‘Cool Hand Luke’, and modelling his behaviour on the abusive county sheriff depicted in it. Interviewed by Alastair Leithead (2011), Eshleman commented: “...I made the decision I would take on the persona of a very cruel prison guard.”) However, Zimbardo strongly suggested that the participants’ experiences were all too real and that, even if they were only role-playing at the beginning of the study, as the study progressed they were internalising these roles and rapidly got to the point where they could no longer differentiate between role-playing and self

• The study can also be criticised for its unrepresentative sample. Since the experiment was conducted using 24 normal, healthy, male college students who were predominantly middle class and white (one was described as oriental), care needs to be taken in generalising the results to other people
• Importantly the study has been criticised for lacking ecological validity. For practical and ethical reasons the simulated prison could not be totally realistic. Many particularly unpleasant aspects of prison life were absent, such as involuntary homosexuality, racism, beatings and threats to life. Also, the maximum anticipated sentence was just two weeks. All of which makes it possible the study does not serve as a meaningful comparison to real prison environments. However, there is considerable evidence that the participants did react to the situation as though it was real. Eg: 90% of the prisoners’ private conversations, which were monitored by the researchers, were on the prison conditions, and only 10% of the time were their conversations about life outside of the prison. The guards, too, rarely exchanged personal information during their relaxation breaks - they either talked about ‘problem prisoners’, other prison topics, or did not talk at all. The guards were always on time and even worked overtime for no extra pay. When the prisoners were introduced to a priest, they referred to themselves by their prison number, rather than their first name. Some even asked him to get a lawyer to help get them out!

A main strength of the study was the way it managed to maintain some degree of control and some ecological validity. The situation was very tightly controlled - eg: guards and prisoners were randomly allocated and were selected using a stringent criterion. The study still had ecological validity in the way that Zimbardo went to great extremes in making the study as true to life as possible -eg: in the way that he had the prisoners arrested from their homes.

A further strength was in the way that Zimbardo collected data.  

It is also worth noting that Zimbardo’s conclusions can be seen as too deterministic. Eg: in his study not all of the participants behaved in the same way. Some of the guards were less willing to abuse their power. Perhaps the reason why some of the participants were less willing was something to do with their personalities - ie: there could be a dispositional element in their behaviour!

Guard ‘B’ said in debrief: “I made sure I was one of the guards on the yard [when the prisoners were first admitted] because this was my first chance for the kind of manipulative power that I really like - being a very noticed figure with complete control over what is said or not.” Guard C said: “Acting authoritatively can be fun. Power can be a great pleasure.”

Alex Haslam & Steve Reicher, psychologists from the University of Exeter and University of St Andrews, conducted the ‘BBC Prison Study’ in 2002, a partial replication of the experiment with the assistance of the BBC, who broadcast scenes from the study in a documentary program called ‘The Experiment’. Their results and conclusions differed from Zimbardo's in that the prisoners largely came to dominate the guards. While their procedure was not a direct replication of Zimbardo's, their study cast further doubt on the generality of his conclusions. Specifically, it questions the notion that people slip mindlessly into role.

In 2004, Zimbardo testified for the defense in the court martial of Sgt Ivan ‘Chip’ Frederick, a guard at Abu Ghraib prison. He argued that Frederick's sentence should be lessened due to mitigating circumstances, explaining that few individuals can resist the powerful situational pressures of a prison, particularly without proper training and supervision. The judge apparently disregarded Zimbardo's testimony, and gave Frederick the maximum 8-year sentence. Zimbardo drew on the knowledge he gained from his participation in the Frederick case to write a new book entitled, ‘The Lucifer Effect: Understanding How Good People Turn Evil’, about the connections between Abu Ghraib and the Stanford Prison Experiment. (For an Integrated SocioPsychology commentary on the events at Abu Ghraib, see the Blog: ‘Prisoner Abuse & the Mess in Iraq’.)