Zimbardo - Stanford Prison Experiment
Aim: To investigate how readily people would conform to the roles of guard and prisoner in a
role-playing exercise that simulated prison life.
Zimbardo (1973) was interested in finding out whether the brutality reported among guards in
American prisons was due to the sadistic personalities of the guards (i.e. dispositional) or had
more to do with the prison environment (i.e. situational). For example, prisoner and guards may
have personalities which make conflict inevitable, with prisoners lacking respect for law and
order and guards being domineering and aggressive. Alternatively, prisoners and guards may
behave in a hostile manner due to the situation they are placed in.
If the prisoners and guards behaved in a non-aggressive manner this would support the
dispositional hypothesis, or if they behave the same way as people do in real prisons this would
support the situational explanation.
Procedure: To study the roles people play in prison situations, Zimbardo converted a basement
of the Stanford University psychology building into a mock prison. He advertised for students to
play the roles of prisoners and guards for a fortnight. 24 male college students (chosen from 75
volunteers) were screened for psychological normality and paid $15 per day to take part in the
experiment.
Participants were randomly assigned to either the role of prisoner or guard in a simulated prison
environment. There were 2 reserves and one dropped out, finally leaving 10 prisoners and 11
guards. The guards worked in sets of 3 (being replaced after an 8 hour shift), and the prisoners
were housed 3 to a room. There was also a solitary confinement cell for prisoners who
, 'misbehaved'. The prison simulation was kept as “real life” as possible.
Prisoners were treated like every other criminal, being arrested at their own homes, without
warning, and taken to the local police station. They were fingerprinted, photographed and
‘booked’. Then they were blindfolded and driven to the psychology department of Stanford
University, where Zimbardo had had the basement set out as a prison, with barred doors and
windows, bare walls and small cells. Here the deindividuation process began.
When the prisoners arrived at the prison they were stripped naked, deloused, had all their
personal possessions removed and locked away, and were given prison clothes and bedding.
They were issued a uniform, and referred to by their number only. Their clothes comprised a
smock with their number written on it, but no underclothes. They also had a tight nylon cap, and
a chain around one ankle.
Aim: To investigate how readily people would conform to the roles of guard and prisoner in a
role-playing exercise that simulated prison life.
Zimbardo (1973) was interested in finding out whether the brutality reported among guards in
American prisons was due to the sadistic personalities of the guards (i.e. dispositional) or had
more to do with the prison environment (i.e. situational). For example, prisoner and guards may
have personalities which make conflict inevitable, with prisoners lacking respect for law and
order and guards being domineering and aggressive. Alternatively, prisoners and guards may
behave in a hostile manner due to the situation they are placed in.
If the prisoners and guards behaved in a non-aggressive manner this would support the
dispositional hypothesis, or if they behave the same way as people do in real prisons this would
support the situational explanation.
Procedure: To study the roles people play in prison situations, Zimbardo converted a basement
of the Stanford University psychology building into a mock prison. He advertised for students to
play the roles of prisoners and guards for a fortnight. 24 male college students (chosen from 75
volunteers) were screened for psychological normality and paid $15 per day to take part in the
experiment.
Participants were randomly assigned to either the role of prisoner or guard in a simulated prison
environment. There were 2 reserves and one dropped out, finally leaving 10 prisoners and 11
guards. The guards worked in sets of 3 (being replaced after an 8 hour shift), and the prisoners
were housed 3 to a room. There was also a solitary confinement cell for prisoners who
, 'misbehaved'. The prison simulation was kept as “real life” as possible.
Prisoners were treated like every other criminal, being arrested at their own homes, without
warning, and taken to the local police station. They were fingerprinted, photographed and
‘booked’. Then they were blindfolded and driven to the psychology department of Stanford
University, where Zimbardo had had the basement set out as a prison, with barred doors and
windows, bare walls and small cells. Here the deindividuation process began.
When the prisoners arrived at the prison they were stripped naked, deloused, had all their
personal possessions removed and locked away, and were given prison clothes and bedding.
They were issued a uniform, and referred to by their number only. Their clothes comprised a
smock with their number written on it, but no underclothes. They also had a tight nylon cap, and
a chain around one ankle.
