Evaluation
Control – Lack of realism –
One strength of the SPE is that Zimbardo and his One limitation of the SPE is that it did not have the realism of a true prison.
colleagues had control over key variables. Ali Banuazizi and Siamak Movahedi (1975) argued the participants were merely play-acting rather
The most obvious example of this was the selection of than genuinely conforming to a role. Participants' performances were based on their stereotypes of
participants. Emotionally stable individuals were how prisoners and guards are supposed to behave. For example, one of the guards claimed he had
chosen and randomly assigned to the roles of guard based his role on a brutal character from the film Cool Hand Luke. This would also explain why the
and prisoner. This was one way in which the prisoners rioted - they thought that was what real prisoners did. This suggests that the findings of
researchers ruled out individual personality differences the SPE tell us little about conformity to social roles in actual prisons. Counterpoint - However,
as an explanation of the findings. If guards and Mark McDermott (2019) argues that the participants did behave as if the prison was real to them.
prisoners behaved very differently, but were in those For example, 90% of the prisoners' conversations were about prison life. Amongst themselves, they
roles only by chance, then their behaviour must have discussed how it was impossible to leave the SPE before their 'sentences' were over. 'Prisoner 416
been due to the role itself. This degree of control over later explained how he believed the prison was a real one but run by psychologists rather than the
variables increased the internal validity of the study, so government. This suggests that the SPE did replicate the social roles of prisoners and guards in a
we can be much more confident in drawing real prison, giving the study a high degree of internal validity.
conclusions.
Exaggerates the power of roles: Alternative explanation:
Another limitation is that Zimbardo may have Zimbardo's explanation for the guards' (and prisoners)
exaggerated the power of social roles to influence behaviour was that conforming to a social role comes
behaviour (Fromm 1973). "naturally and easily. Being given the role of guard
For example, only one-third of the guards behaved in a means that these participants will inevitably behave
brutal manner. Another third tried to apply the rules brutally because that is the behaviour expected of
fairly. The rest actively tried to help and support the someone with that role.
prisoners. They sympathised, offered cigarettes, and However, Steve Reicher and Alex Haslam (2006)
reinstated privileges (Zimbardo 2007). Most guards criticise Zimbardo's explanation because it does not
were able to resist situational pressures to conform to account for the behaviour of the non-brutal guards.
a brutal role. This suggests that Zimbardo overstated They used social identity theory (SIT) instead to argue
his view that SPE participants were conforming to that the 'guards' had to actively identify with their
social roles and minimised the influence of social roles to act as they did.
dispositional factors (e.g., personally).
Control – Lack of realism –
One strength of the SPE is that Zimbardo and his One limitation of the SPE is that it did not have the realism of a true prison.
colleagues had control over key variables. Ali Banuazizi and Siamak Movahedi (1975) argued the participants were merely play-acting rather
The most obvious example of this was the selection of than genuinely conforming to a role. Participants' performances were based on their stereotypes of
participants. Emotionally stable individuals were how prisoners and guards are supposed to behave. For example, one of the guards claimed he had
chosen and randomly assigned to the roles of guard based his role on a brutal character from the film Cool Hand Luke. This would also explain why the
and prisoner. This was one way in which the prisoners rioted - they thought that was what real prisoners did. This suggests that the findings of
researchers ruled out individual personality differences the SPE tell us little about conformity to social roles in actual prisons. Counterpoint - However,
as an explanation of the findings. If guards and Mark McDermott (2019) argues that the participants did behave as if the prison was real to them.
prisoners behaved very differently, but were in those For example, 90% of the prisoners' conversations were about prison life. Amongst themselves, they
roles only by chance, then their behaviour must have discussed how it was impossible to leave the SPE before their 'sentences' were over. 'Prisoner 416
been due to the role itself. This degree of control over later explained how he believed the prison was a real one but run by psychologists rather than the
variables increased the internal validity of the study, so government. This suggests that the SPE did replicate the social roles of prisoners and guards in a
we can be much more confident in drawing real prison, giving the study a high degree of internal validity.
conclusions.
Exaggerates the power of roles: Alternative explanation:
Another limitation is that Zimbardo may have Zimbardo's explanation for the guards' (and prisoners)
exaggerated the power of social roles to influence behaviour was that conforming to a social role comes
behaviour (Fromm 1973). "naturally and easily. Being given the role of guard
For example, only one-third of the guards behaved in a means that these participants will inevitably behave
brutal manner. Another third tried to apply the rules brutally because that is the behaviour expected of
fairly. The rest actively tried to help and support the someone with that role.
prisoners. They sympathised, offered cigarettes, and However, Steve Reicher and Alex Haslam (2006)
reinstated privileges (Zimbardo 2007). Most guards criticise Zimbardo's explanation because it does not
were able to resist situational pressures to conform to account for the behaviour of the non-brutal guards.
a brutal role. This suggests that Zimbardo overstated They used social identity theory (SIT) instead to argue
his view that SPE participants were conforming to that the 'guards' had to actively identify with their
social roles and minimised the influence of social roles to act as they did.
dispositional factors (e.g., personally).
