Stanford Prison Experiment

Briefly explain the findings of the experiment

- After a slow start, the guards took up their roles with enthusiasm - Their behaviour became a threat to the prisoners' psychological and physical health, and the study was stopped after six days instead of the intended 14 days - Within 2 days, the prisoners rebelled against their harsh treatment by the guards. They ripped their uniforms, and shouted and swore at the guards, who retaliated with fire extinguishers. - The guards employed 'divide-and-rule' tactics by playing the prisoners off against each other - They harassed the prisoners constantly, to remind them they were being monitored all the time. E.g. they conducted frequent headcounts, sometimes in the middle of the night, when the prisoners would stand in line and call out their numbers. - The guards highlighted the difference in social roles by creating plenty of opportunities to enforce the rules and punish even the smallest misdemeanour - After their rebellion was put down, the prisoners became subdued, depressed and anxious. One prisoner was released on the first day because he showed symptoms of psychological disturbance. Two more were released on the fourth day. - One prisoner went on a hunger strike. The guards attempted to force-feed him and punished him by putting him in the 'hole'. Instead of being considered a hero, he was shunned by the other prisoners; "Prisoner 819 did a bad thing" - The guards identified more and more closely with their role. Their behaviour became more brutal and aggressive, with some of them appearing to enjoy the power they had over prisoners.

How many rules did the guards make for the prisoners to follow?

16 rules

How many participants were there?

24 male volunteers

Ethical issues evaluation point

A major ethical issue arose because of Zimbardo's dual roles in the study. For example, on one occasion a student who wanted to leave the study spoke to Zimbardo in his role as superintendent. The whole conversation was conducted on the basis that the student was a prisoner in a prison, asking to be 'released'. Zimbardo responded to him as a superintendent worried about the running of his prison rather than as a researcher with responsibilities towards his participants.

Control evaluation point

A strength of the SPE is that Zimbardo and his colleagues had some control over variables. The most obvious example of this was the selection of the participants. Emotionally stable individuals were chosen and randomly assigned to the roles of guard and prisoner. This was one way in which the researchers tried to rule out individual personality differences as an explanation of the findings. Having such control over variables is a strength because it increases the internal validity of the study. So we can be much more confident in drawing conclusions about the influence of roles on behaviour.

When was the Stanford prison experiment conducted?

August 1971

Lack of realism evaluation point

Banuazizi and Mohavedi (1975) argued the participants were merely play-acting rather than genuinely conforming to a role. Their performances were based on their stereotypes of how prisoners and guards are supposed to behave. For example, one of the guards claimed he had based his role on the brutal character from 'Cool Hand Luke'. This would also explain why the prisoners rioted - because they thought that was what real prisoners did. But Zimbardo pointed to evidence that the situation was very real to the participants. 'Prisoner 416' expressed the view that the prison was a real one, run by psychologists rather than the government. On balance, it seems that the situation was real to participants, which gives the study a high degree of internal validity.

What was the aim of the experiment?

Do prison guards behave brutally because they have sadistic personalities, or is it the situation that created such behaviour?

Role of dispositional influences evaluation point

Fromm (1973) accused Zimbardo of exaggerating the power of the situation to influence behaviour, and minimising the role of personality factors. For example, only a minority of the guards (about 1/3) behaved in a brutal manner. Another third were keen on applying the rules fairly. The rest actively tried to help and support the prisoners, sympathising with them, offering them cigarettes and reinstating privileges. This suggests that Zimbardo's conclusion - that Ps were conforming to social roles - may be overstated. The differences in the guards' behaviour indicate that they were able to exercise right and wrong choices, despite the situational pressures to conform.

What tests did the participants have to pass to be in the experiment?

The participants went through extensive psychological tests and only those deemed 'emotionally stable' were selected

What were the conclusions of the experiment?

The stimulation revealed the power of the situation to influence people's behaviour. Guards, prisoners and researchers all conformed to their roles within the prison. These roles were easily taken on by the participants - even volunteers who came in to perform certain functions (such as the 'prison chaplain') found themselves behaving as if they were in a prison rather than a psychological study.

How were the roles selected?

The students were randomly assigned the roles of guards or prisoners

What were guards allowed to do and not do to the prisoners?

They could give them orders, punish them with exercise, insult them, decide when they went to the toilet, wake them at night to do chores, but they were not allowed to physically hurt them.

What happened to those 'prisoners' on the morning of the start of the experiment?

They were arrested by the local police at their houses, blindfolded and taken to the mock prison to heighten the realism of the study

What happened to the prisoners when they arrived at the mock prison?

They were strip-searched, deloused and issued a uniform and given a number to replace their name

What uniform did the guards wear?

They wore a typical police uniform, including wooden clubs, handcuffs, keys and mirrored sunglasses

Define social roles

the 'parts' people play as members of various social groups. Everyday examples include parent, child, student, passenger and so on. These are accompanied by expectations we and others have of what is appropriate behaviour in each role

How did they get volunteers for the experiment?

they put an advert into the local newspaper for male volunteers to be in a 'psychological study of prison life'