The Prison Studies
Relaunched: 27 October 2020
Philip Zimbardo’s ‘Stanford Prison Experiment’ (Craig Haney, Curtis Banks & Philip Zimbardo, 1973), is one of the most important, controversial and ethically dubious psychological studies ever undertaken – something of a classic bête noire on a par with some of Stanley Milgram’s obedience experiments. It raises issues around key psychological concepts such as the identification process in conformity and deindividuation – along with a plethora of ethical issues. Thus, it is a critically-important study for a number of reasons – not least because, according to Zimbardo, it tells us how people will conform to a group norm. Sometimes with very disturbing results.
Some 30 years later Steve Reicher & Alex Haslam (2006) carried out a partial replication of Stanford – their study is often referred to as the ‘BBC Prison Study’ because the BBC funded the study and edited it into a series which was broadcast in 2006. The outcome of their study was quite different to that of Zimbardo.
However, these different outcomes can be explained via complementary psychological theories.
The Stanford Prison Experiment
Zimbardo was interested in testing the dispositional hypothesis that widespread problems in American prisons were due to the intrinsic nature of the prison guards and the prisoners. It had been argued that prison guards bring to their jobs a particular ‘guard mentality’ and, thus, are therefore attracted to the job as they are already sadistic and insensitive people. Whereas prisoners have no respect for law and order and bring this aggressiveness and impulsivity to the prison. Zimbardo wanted to demonstrate that conditions in the prisons were not due to the type of individuals working and incarcerated in the prisons but could be best explained using a situational attribution. In particular he believed that the conditions were influenced by the social roles that prisoners and prisoner guards are expected to play.
In August 1971, with funding from the US Navy and the US Marine Corps, Zimbardo set out to show that people allocated to be ‘prison guards’ or ‘prisoners’ would tend to slip into those predefined roles, behaving in a way that they thought was required, rather than using their own judgement and morals. Zimbardo hoped the knowledge gained could be applied to real-
The video below provides a basic introduction to the study.
The study is usually described as an experiment with the independent variable being the conditions the participants are randomly allocated to: either prisoner or guard. The dependent variable is the resulting behaviour. The study can also be described as a simulation as it was attempting to create a prison like environment. Data collected were combinations of both quantitative and qualitative data. The main data though was qualitative and was obtained using video, audiotape and direct observation (both covert and overt).
The participants were respondents to a newspaper advertisement, which asked for male volunteers to participate in a psychological study of ‘prison life’ in return for payment of $15 per day. The 75 respondents completed a questionnaire about their family background, physical and mental health, prior experiences and attitudinal tendencies with respect to psychopathology and any involvement in crime. Based on the results of the tests, 24 men were selected. These 24 were judged to be the most physically and mentally stable, most mature and least involved in anti-social behaviours. The participants were described as “normal, healthy male college students who were predominantly middle class and white”. The 24 participants did not know each other prior to the study.
A simulated prison was built in the basement of the Psychology building at Stanford University. For the duration of the study 9 ‘prisoners’ were to remain in the mock prison for 24 hours per day for up to 2 weeks. 3 were to be arbitrarily assigned to each of the 3 cells; the other participants nominated ‘prisoners’ were to be on stand-
Those participants allocated the role of guards had to attend an ‘orientation meeting’ the day before the induction of the prisoners. They met the principal researchers, the ‘superintendent’ of the prison (Zimbardo) and the ‘warden’ (an undergraduate research assistant). They were told that the “experimenters wanted to try to simulate a prison environment within the limits imposed by pragmatic and ethical considerations”. Their assigned task as prison guards was to enforce 16 rules to ensure “a reasonable degree of order” –
The uniforms of both prisoners and guards were intended to increase group identity and reduce individuality within the 2 groups – deindividuation. The guards’ uniform consisted of a plain khaki shirt and trousers, a whistle, a police night stick (a wooden baton) and reflecting sunglasses to make eye contact impossible. The guards’ uniforms were intended to convey a military attitude while the baton and whistle were symbols of control and power. The prisoners’ uniform consisted of a loose-
On the chosen Sunday morning the 9 ‘prisoners’ waiting at home “to be called” for the start of the experiment found their homes were raided without warning by real local police officers! They were arrested on suspicion of burglary or armed robbery, advised of their rights, handcuffed, thoroughly searched (often in full view of their neighbours and passers by) and driven in the back of a police car to the police station. (The Palo Alto Police had agreed to help with the experiment!) As if they were real-
The ‘prisoners’ were then blindfolded and driven by one of the experimenters and a ‘guard’ to the basement of Jordan Hall (‘Stanford County Prison’). At the mock prison, each prisoner was stripped, sprayed with a delousing preparation (a deodorant spray) and made to stand alone and naked in the ‘yard’. After being given their uniform and having a mug shot taken, the prisoner was put in his cell and ordered to remain silent. The warden read them the rules of the institution which were to be memorised and had to be followed. Prisoners were to be referred to only by the number on their uniforms –
Every day the participants were allowed 3 bland meals, 3 supervised toilet visits and given 2 hours for the privilege of reading or letter writing. Work assignments had to be carried out and 2 visiting periods per week were scheduled, as were movie rights and exercise periods. 3 times a day prisoners were lined up for a ‘count’ (one on each guard work-
On the second day of the experiment the prisoners ripped the identifying numbers from their uniforms and organised a mass revolt and riot, as a protest about the conditions. They taunted and cursed the guards. Guards worked extra hours and devised a strategy to break up and put down the riot, using fire-
Despite the fact that guards and prisoners were essentially free to engage in any form of interaction, the nature of their encounters tended to be negative, hostile, insulting and dehumanising. The guards started most of the interactions, many of which were in the form of commands or verbal affronts, while the prisoners adopted a generally passive response mode. Although it was clear to all participants that the experimenters would not permit physical violence to take place, varieties of less direct aggressive behaviour were often observed. Lengthy prisoner counts became a trial of ordeal –
Initially punishments took the form of loss of privileges but the guards rapidly increased total control of each prisoner’s life, including going to the toilet. Prisoners were often not allowed to use the toilet and forced to urinate or defecate in a bucket in their cell –
The humiliation and dehumanisation got so severe, that the experimenters had to frequently remind the guards to refrain from such tactics.
Prisoners became passive, excessively obedient, showed flattened mood and distorted perception of self, often slouching and keeping their eyes fixed to the ground, They had become institutionalised very quickly and adapted to their roles. One third of the guards began to show an extreme streak of sadism; and some of them were so enthusiastic that they volunteered to work extra hours without pay. Zimbardo himself started to become internalised in the experiment. The prisoners started to experience acute emotional disturbance, acute anxiety, crying and rage. They exhibited disorganised thinking, uncontrollable crying, withdrawing and behaving in pathological ways.
Overall, researchers had to release 5 prisoners from the experiment prematurely –
Other people connected to the experiment were also sucked in by the situation. The experimenters forgot that they were there to observe and collect data. Instead, they started to assume the role of prison staff and supervisor. A priest who visited the prison started to contact parents of the prisoners about arranging lawyers to bail them out. The parents, who had visited the prison themselves, seem to also have forgot that their sons had the right to withdraw from the experiment. They actually started to arrange lawyers. And a lawyer actually came…with 5 prisoners appearing before a ‘parole board’! (One prisoner developed a rash over his entire body when his ‘parole’ was rejected!) However, when on the fourth day, Zimbardo and the guards attempted to move the prisoners to the more secure local police station on the basis that some prisoners were talking about trying to escape, the officials at the station said they could no longer participate in the experiment.
The experiment carried on for 6 days until an outside psychologist, Christina Maslach –
All of the remaining prisoners were delighted by the end of the experiment; but most of the guards seemed to be distressed by the premature end to the study –
An extremely high level of conformity was observed of ‘guards’ and ‘prisoners’ to their social roles. However, many participants reported afterwards that they had acted ‘out of character’ and had not really changed the way they thought about things (private opinion). Effectively they were disassociating themselves from their behaviour.
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 either as a guard or a prisoner).
Below is Kim Duke’s documentary of the Stanford Prison Experiment Experiment –
In his analysis, Zimbardo categorised approximately 30% of the guards as ‘cruel and tough’; about 50% were ‘tough but fair’; and less than 20% were ‘good guards’ (generally helpful and kind to the prisoners). He 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 early on in the study (‘pathology of power’) as demonstrated that, even after the first day, all prisoner rights 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 did 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.