Experiment: A study of prisoners and guards in a simulated prison - page 46 Oxford Revision Book
Aim: To demonstrate the situational rather than the dispositional causes of negative behaviour and throught patterns found in prison settings by conducting a prison stimulation with ‘normal’ subjects playing the roles of guard and prisoner.
Method: Subjects - 22 male subjects selected (through personality assessment). Mostly Caucasian, middle class, college students
Apparatus - Prison, basement corridor in Stanford University Psychology department, in each prisoner room included covert video and audiotape data recording. Uniforms - role of identification, guards given khaki shirts and trousers, batons and reflecting sunglasses while prisoners wore loose fitting smocks and ID numbers.
Procedure:Observation through covert video and audiotape data recording. Prisoners were arrested by real police outside their houses by surprise under the norm procedures and the guards worked 8 hour shifts and were only given the instructions to ‘maintain a reasonable degree of order within the prison necessary for its effective functioning and a prohibition against the use of physical violence.
Findings: Prisoners showed signs of depression, crying, fits of rage and acute anxiety. The experimenters proposed that these reactions were caused by a loss of personal identity, emasculation, dependency and learned helplessness due to the structures of the prison system.
Guards showed ‘Pathology of Power’ - the huge enjoyment of the power at their disposal.
Conclusion: They conformed to their roles or were into their roles too much due to the situation and not the dispositional factors (like their own personalities)
Ethical: It was unethical as the participants were both mentally and physically hurt.
Strengths:

• Did prove to be true in one case http://www.psychologistworld.com/influence_personality/stanfordprison.php
This was about the Abu Ghraib prison abuse where under the authority of American armed forces, they treated prisoners very harshly. (This was during the aftermath of 2003 Iraq war)

Weaknesses:

• There is lack of ecological validity as simulation lacks ‘mundane realism’.
• Ethical guidelines breached: Caused dramatic and disturbing results, such as physical and mental harm
• Subjects were only debriefed months to years after the experiment
• There was conformed consent but not enough information