Keith E Rice's Integrated SocioPsychology Blog & Pages

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The Prison Studies #2

Evaluation of the Stanford Prison Experiment
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 – in effect he undermined his own competence to conduct the study,  competence of the researcher being somewhat  belatedly recognised as a key ethical issue by the British Psychological Society in 2006
  • 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. (Zimbardo had some idea that the mock guards would abuse the mock prisoners because that is exactly what happened in a pilot study before the main study!)
  • 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 later, 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 Eshelman, 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 homosexualityracism, beatings and threats to life. Also, the maximum anticipated sentence was just 2 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.

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.”

What the Stanford experience seems to have done for at least some of the guards was to allow them to express their RED vMEME’s lust for power with only relatively-minimal BLUE procedural restraint. It is also more than likely that the more callous guards – especially Eshelman – in their displays of ruthlessness were exhibiting the Psychoticism Dimension of Temperament. As for the prisoners, it seems, after an initial attempt at rebellious solidarity, they failed to find any real tribal bonding. With the acute stress they suffered, it is arguable that the prisoners largely scaled down to BEIGE in a determination to simply endure and survive the situation.

What is particularly interesting is the way memes worked in the mock prison environment. One prisoner, after an interview with ‘Governor Zimbardo’, went back to his fellow prisoners and stated: “We can’t leave!” In fact, Zimbardo had not said that explicitly; rather he more subtlely stated that it would seriously undermine the experiment if participants left and, therefore, they had a responsibility to stay. (This was not too dissimilar to some of the ‘prods’ Milgram used in his obedience experiments.) Within hours that meme spread to all the prisoners and led to the shared notion that they really did need some external means – eg: a lawyer – to ensure they could get out.

For all the outrage the Stanford Prison Experiment invoked, Zimbardo’s study influenced Congress to change one law so that juveniles accused of federal crimes would no longer be housed with adult prisoners before trial (to prevent them from being abused).

In 2004, Zimbardo testified for the defence in the court martial of Sgt Ivan ‘Chip’ Frederick, a guard at Abu Ghraib prison where American soldiers had grossly mistreated Iraqi prisoners and facilitated murder, torture and rape. 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.)

The BBC Prison Study
Steve Reicher & Alex Haslam conducted the ‘BBC Prison Study’ in 2002, a partial replication of Zimbardo’s experiment. The project was partly funded by and carried out in conjunction with the BBC. In part the study was aiming to revisit some of the issues raised by the Stanford Prison Experiment. Their results and conclusions differed from Zimbardo’s.

While their procedure was not a direct replication of Zimbardo’s, their study cast further doubt on the generalisation of his conclusions. Specifically, it questions the notion that people slip mindlessly into role and Zimbardo’s situationalist explanation for the guards’ aggression in his study: that they were simply conforming to the behaviour expected of that social role. Reicher & Haslam (2006) disagreed, arguing that the Stanford guards’ and prisoners’ behaviour was not due so much to a natural acceptance of their roles but may have been more to do with the instructions given to them by Zimbardo. Furthermore, Reicher & Haslam note that, in the Zimbardo study, there were individual differences whereby some of the guards were tough but fair and others less fair – dispositional factors. This challenges Zimbardo’s view that behaviour in the Stanford Prison Experiment was solely due to identification with the social role.

Reicher & Haslam also take issue with the notion that groups per se are the root of anti-social behaviour. They argue that powerful and effective groups provide a good psychological safeguard against tyranny and that it is when groups prove ineffective that tyrannical forms of social organisation begin to become attractive.

Reicher & Haslam draw on Henri Tajfel & John Turner’s (1979) Social Identity Theory to explain inter-group dynamics. They argue that our acceptance of roles depends on how much we internalise the membership of a group, its norms and values and its sense of status (social comparison). Eg: if people are in a higher-status group (such as guards) they will tend to identify with that group, invest self-esteem in it and behave accordingly. Correspondingly, people in a lower-status group are less likely to internalise its values.

However, this may be mediated by the perceived level of permeability – a individual’s belief about their opportunity to move from one group to another. If permeability is low, then they perceive less opportunity to move from one group to another more, higher-status group. Accordingly people are more likely to identify with the group they are effectively stuck with and to act collectively as a group.

Also important is a person’s belief about the legitimacy of group inequalities. If members of a group believe that the inequalities between groups are unfair, the members will be more likely to act collectively to challenge the status quo. To effectively challenge inequalities between groups, members of a group must be aware of the cognitive alternatives available.. Cognitive alternatives occur when members of a lower-status group become aware of ways in which social relations could be restructured in order to bring about social change. As cognitive alternatives become available, the prediction is that there will be a challenge to existing authority.

To some extent, in this analysis, Reicher & Haslam are also drawing upon John Duckitt’s (1994) extension of Realistic Conflict Theory to address inter-group hostility related to inequality.

However, Reicher & Haslam set out to outline a theoretical framework for understanding tyranny – defined by them as “an unequal social system involving the arbitrary or oppressive use of power by one group or its agents over another.”

Accordingly, Reicher & Haslam wanted to do far more than just replicate Zimbardo – though that was the basis of the BBC’s original intention. Rather, they wanted to create an institution to investigate the behaviour of groups that were unequal in terms of power, status, and resources.

Specifically, their aims were:-

  • To provide evidence of the unfolding interactions between groups of unequal power
  • To investigate if dominant group members will identify with their group from the start and impose their power – and without constraint
  • To investigate if subordinate group members will identify collectively and challenge inter-group inequalities when relations between groups are seen as impermeable and insecure
  • To measure the social, organisational and clinical effects of the study on the participants
  • To develop a practical and ethical framework for examining social psychological issues in large-scale studies

The study was monitored throughout by an independent 5-person ethics committee led by Liberal Democrat MP Lembit Öpik. 2 independent clinical psychologists monitored the study, could contact participants and ask for them to be withdrawn. A paramedic was kept on permanent standby and on-site security guards were ready to intervene if behavior became dangerous. The 15 participants were all male and met the criteria of being normal, decent and well adjusted individuals. They were recruited through advertisements in the national press and through leaflets. (The adverts, headlined “How well do you really know yourself?”, warned potential volunteers that they would be faced with “hardship, hunger, solitude, anger”.) For ethical reasons only people who were well-adjusted and pro-social, scoring at low levels on all social and clinical measures were included in the study. Men were chosen so that the results could be compared with Zimbardo and because it was thought by the researchers to cause fewer ethical problems than using women. From an initial pool of 332 applicants, the researchers reduced the sample to 27 men. The final sample of 15 was chosen to ensure diversity of age, social class and ethnic background. The 15 participants were first divided into 5 groups of 3 people who were as closely matched as possible on personality such as racism, authoritarianism and social dominance. From each group of 3, one participant was then randomly selected to be a guard (and the remaining 2 to be prisoners). One prisoner was not involved at the beginning of the study.

The study was designed to create a hierarchical society in which people would live for up to 10 days. It was conducted within an institutional environment that was constructed inside Elstree Film Studios in north London. Prisoners were allocated to lockable 3-person cells that were located, together with showers, off a central atrium. This was separated by a lockable steel mesh fence from the guards’ quarters (a dormitory, bathroom, and mess room).  Participants could be both video and audio recorded wherever they were.

There was also daily psychometric testing. The participants were tested on:-

  • Social variables: social identification, awareness of cognitive alternatives, right-wing authoritarianism
  • Organizational variables: compliance with rules, organisational citizenship;
  • Clinical variables: self-efficacy, Depression.

Furthermore, daily swabs of saliva were taken in order to ascertain cortisol levels as a measure of stress.

The 5 guard participants were invited to a hotel the evening before they entered the prison and were told that they would be guards in the study. They were told that their responsibility was to ensure that the institution ran as smoothly as possible and that the prisoners performed all their tasks. The five guards were then asked to draw up a series of prison rules and to draw up a series of punishments for rule violations. They also had to devise routines which enabled roll calls to be held and allocated work duties to prisoners. The guards were given no guidance about how they should achieve their goals. The only limits on what they could do were a set of ethically determined ‘basic rights’ for prisoners. All participants were told that physical violence would not be tolerated. Beyond this, however, it was stressed that the guards could act as they pleased.

In their analysis Reicher & Haslam divided their findings from their investigation into 2 phases:-

Rejecting Inequality (Days 1 to 6)
Days 1-2
On the morning of Day 1 of the study, the guards were taken in a blacked-out van to the prison (since this was meant to be their entire experiential world for the duration of the study, it was important that they could not imagine the outside). Once inside, they were given a full briefing by the researchers on the prison layout and the resources available to them. The guards had a series of means by which to enforce their authority, including keys to all doors inside the prison (including a punishment isolation cell), sole access to an upper level, a ‘guards’ station’ with a surveillance system from which they could see into the prisoners’ cells, resources (including snacks and cigarettes) to use as rewards or to withdraw as punishments – and, in addition, the ability to put prisoners on a bread and water diet. The guards also had far better conditions than the prisoners, including superior meals, extra supplies of drinks and snacks, superior living conditions and well-made uniforms. After their briefing, the guards changed into their uniforms and practiced the procedure for admitting the prisoners.

The 9 prisoners then arrived one at a time. Their heads were shaved, everyday clothes were taken away and they had to shower. The prisoners’ uniform consisted of a t-shirt printed with a 3-digit number, loose trousers and flimsy sandals. They were given the prison rules and a list of basic rights before being put into cells.

At their initial briefing, the guards were told that they had been selected from pre-selection assessment scales because of their reliability, trustworthiness and initiative. However, they were also told that while these scales were reasonably reliable, they were not perfect. In particular, the researchers stated that it was possible that they had misassigned one or more of the prisoners. Hence, the guards were told that they should observe the behaviour of the prisoners to see if anyone showed guard-like qualities. If they did, they were told that there was provision for a promotion to be made on Day 3. This was the first of 2 planned interventions.

This information was also announced to the prisoners over the loudspeaker, creating a competitive factor or permeability. In the initial days of the study, participants were thus led to believe that movement between groups was possible.

Contrary to the researchers’ expectations the guards did not identify with their own group and did not behave collectively – in spite of it being a higher-status group. Some of the guards did identify with their role but most of them did not. Most of the guards were very conscious of the role but felt that it was undeserved and were conscious of how they appeared to other people and concerned about abusing their power. Eg: some of the guards even tried to give away some of their resources such as food (sausages). However, the prisoners were unhappy that the guards were only doing this out of guilt, so they declined despite eating little the day before. In refusing the food the guards offered, the prisoners denied their power.

It was found that the guards were not able to form a plan of action because they didn’t work as a group. As expected the prisoners also lacked a social identity, probably because they were aware of the ability to gain promotion to the guards group. The prisoners were unhappy with their inferior conditions and some of the prisoners attempted to improve their lot by displaying the individual qualities they thought would be expected for promotion. As a result, there was no shared identity among the prisoners and no consensus about how they should behave. Even though the prisoners could see the weakness of the guards, they were not united to take the guards on. During these first 2 days the guards were able to manage the prisoners because the prisoners lacked a group identity.

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