Zimbardo et al (1973) A Study of Prisoners and Guards in a Simulated prison

Aim

To demonstrate that situational factors (the environment) rather than dispositional factors (personality) cause negative behaviour in prison settings.

This was achieved by conducting a prison simulation with normal participants allocated the roles of either prisoner or guard.

Participants

22 males were selected from a large group of volunteers.

All were considered to be stable, mature and without any anti-social tendencies.

Procedure

The participants were split into prisoners or guards.

The prisoners were taken by surprise by being arrested at home and charged with a crime at a real police station. They were given a prisoner’s uniform and a number.

The guards wore a military style uniform and worked shifts in the prison. They were told to maintain a reasonable degree of order. They were prohibited from using physical violence.

Results

The experiment had to be called off after 6 days because of the abnormal reactions shown by prisoners and guards.

The Guards

Participants showed the “pathology of power.” They enjoyed the power at their disposal and abused the prisoners’ rights. For example they withdrew privileges. They treated going to the toilet and eating as a reward and they verbally abused the prisoners.

The Prisoners

They showed “ Pathological Prisoner Syndrome.” This included disbelief followed by rebellion. They became excessively obedient and half showed signs of depression.

This experiment demonstrates that normal people’s behaviour can quickly be affected by the environment and by conformity to roles.