Stanford prison experiment

• Zimbardo wanted to found out why prison guards behaved brutally which resulted in the study of social roles. Is it because they have sadistic personalities or social roles.
• When did Zimbardo and his colleagues conduct the Stanford prison experiment?

  1973
• Social roles: the ‘parts’ people play as a member of various of social groups. Examples are children, teacher, parent etc. it is accompanied with expectations we and others have of what is appropriate behaviour in the each role.
• What was the sample of the Stanford prison experiment?


  21 male student volunteers
• Where was the experimented located?

  stanford university
• Student were randomly assigned to be either prison guard or prisoner.
• Prisoners and prison guard were encouraged to confirm to social roles through uniform they wore and instructions about their behaviour.
• What 2 way were they encouraged to confirm to social roles?

  By the uniform they wore and the instructions about their behaviour.
• Zimbardo concluded that the situation created by the experiment led to the participants behaving in ways which confirmed to the stereotypical behaviours expected from those in the roles of prison guard and prisoner. This shows how powerful situational factors can be in influencing our behaviour.
• After only six days, Zimbardo decided to end the experiment because he felt it had gone too far. He said that if he hadn’t stopped it then, there is no telling what might have happened.
• This study has been criticised as being unethical because the participants were not fully informed about the nature of the research when they volunteered. They thought they would just be acting out a play but instead found themselves living in a simulated prison environment. Some argue that this lack of consent means that the results are invalid.
• The guards became increasingly sadistic towards prisoners, with some even using electric shocks on them. The prisoners also began to act like real prisoners, becoming depressed and showing signs of mental breakdown.
• The Stanford Prison Experiment was conducted in 1971 by Philip Zimbardo who wanted to investigate whether people could become prisoners and guards simply due to the role they played rather than any inherent personality differences between them.
• Participants were paid $15 per day (equivalent to around $80 today) and given food vouchers worth $36 ($180).
• The guards were told to maintain discipline at all times and use psychological methods such as isolation and sleep deprivation to control the prisoners.
• A strength of the study is that it showed that ordinary people could become cruel and abusive given the right conditions. It highlights the power of situations over individuals and suggests that anyone can behave badly if put into the wrong situation.
• Another criticism is that the study wasn’t random so we don’t know if the same thing would happen again. However, Zimbardo says that similar studies carried out since his show that the effects are consistent across different groups of people.
• Uniforms: The prisoners were given a loose smock to wear and a cap to cover their hair, and they were identified by number (their names were never used). The guards had their own uniform reflecting the status of their role, with wooden club, handcuffs and mirror shades.These uniforms created a loss of personal identity (called de-individuation), and meant they would be more likely to conform to the perceived social role.
• Instructions about behaviour: The prisoners were further encouraged to identify with their role by several procedures. For example rather than leaving the study early, prisoners could 'apply for parole. The guards were encouraged to play their role by being reminded that they had complete power over the prisoners.
• One weakness of this study is that it only involved male participants. Therefore, it may not be representative of how women might react in a similar situation. Another limitation is that the study took place during a time of political unrest in America, meaning that some of the guards may have been influenced by anti-hippy sentiments.
• In the first 2 days, prisoners were seen to rebel right away by ripping their uniforms, shouting and swearing at the guards (prisoner 8612).
• because of the behaviour of the prisoners the first 2 days, John Wayne decided to plan divide and rule tactic by planning prisoners off against each other (416 vs everyone else) and decided to emotionally hurt them to enforce the power they had.
• After the rebellion, lots of prisoners was shown to be depressed and anxious in the prisoner.
• 8612 wad released after 30 hours as he showed huge psychological disturbance.
• AIM: to investigate whether prison guards act brutally because they have sadistics personalities or because of situation/ role they have been put in.
• Social roles

  The 'parts' people play as members of social groups, accompanied by expectations we and others have about what is appropriate behaviour in each role
• Social roles

  • Powerful influences on our behaviour
• Zimbardo and colleagues conducted the Stanford prison experiment (SPE) in the 1970s to investigate why prison guards behave brutally
• Stanford prison experiment (SPE)

  1. Zimbardo et al. (1973) set up a mock prison

  2. Selected 21 men (student volunteers) who tested as 'emotionally stable'

  3. Randomly assigned students to play the role of prison guard or prisoner

  4. Prisoners and guards were encouraged to conform to social roles through uniforms and instructions about behaviour
• Uniforms


  Created a loss of personal identity (called de-individuation) and meant participants would be more likely to conform to the perceived social role
• Instructions about behaviour

  Further encouraged prisoners to identify with their role, and guards to play their role
• The guards took up their roles with enthusiasm, treating the prisoners harshly. Within two days, the prisoners rebelled
• The guards used 'divide-and-rule' tactics, harassing the prisoners constantly to remind them of the powerlessness of their role
• After their rebellion was put down, the prisoners became subdued, depressed and anxious
• The guards identified more and more closely with their role, their behaviour becoming increasingly brutal and aggressive
• Zimbardo ended the study after six days instead of the intended 14
• Strengths of the SPE

  • Zimbardo controlled many variables, such as selecting emotionally-stable individuals and randomly assigning them to roles
  • This increased the internal validity of the study, allowing us to be more confident that the influence of roles on conformity was the cause of the observed behaviour
• Limitations of the SPE

  • Lack of realism - participants may have been 'play-acting' rather than genuinely conforming to roles
  • Zimbardo may have overstated the power of roles to influence behaviour - only one-third of guards behaved in a brutal manner, while others tried to apply the rules fairly or sympathise with prisoners
• What is the name of the famous psychology study conducted by Zimbardo?

  Stanford Prison Experiment
• What was the main focus of Zimbardo's Prison Experiment?

  Investigating causes of prison violence