The Stanford Prison Experiment is a famous psychological study at Stanford University in 1971. Philip Zimbardo, a former classmate of Stanley Milgram – who conducted the obedience experiment – wanted to expand on Milgram’s studies on situational circumstances and human behaviour. Funded by the US Office of Naval Research, Zimbardo and his colleagues (1973) experimented to know if American correctional officers’ cruelty was attributable to their sadistic characters or the prison environment.
Participants:
Setting: basement of the psychology department.
Length: planned to last two weeks; was terminated after six days.
Design: lab experiment, researchers videotaped and observed all subjects.
Sample: 24 white male college students
Procedure:
A newspaper advertisement offering $15 per day to male students interested in participating in a “psychological study of prison life” was used to attract volunteers. After volunteers underwent psychological tests and interviews, the top 24 men were chosen from 75 applicants.
Participants were randomly assigned to the roles of prisoners or guards and placed in a mock prison environment constructed in the psychology department’s basement, which was meant to resemble a natural prison environment closely.
The guards were given a uniform and issued mirrored glasses to avoid eye contact. They were also instructed not to injure the inmates physically. The experiment started when real Palo Alto police ‘arrested’ the prisoners and given to the experimenters.
Prisoners were humiliated to resemble the feeling of being in prison. According to Zimbardo, each prisoner carried a chain padlocked around one ankle and wore a “dress” as their uniform to quickly establish an “atmosphere of oppression.”
On day 2, the prisoners led a rebellion; they refused to leave their cells, ripped off their inmate number tags, insulted the guards, etc. In response, guards sprayed fire extinguishers, removed prisoners’ clothes, got rid of the mattresses and punished the instigators. To prevent this from happening again, the guards created a token system.
Guards quickly became dominant and authoritarian, while prisoners became submissive and compliant. Guards had the freedom to humiliate the prisoners by abusing their authority. They randomly assigned the convicts to do push ups, limited their access to the restrooms and made them relieve themselves in buckets within their cells. Three inmates had to be released early in the first four days.
The guards became highly abusive and unethical as the experiment progressed, while some prisoners became depressed and disorientated. The experiment was only terminated when graduate student Christina Maslach objected to the horrific conditions and questioned the morality of the investigation.
Ethical concerns:
The Stanford Prison Experiment raised severe ethical issues. Critics claim that the study put participants in danger of psychological harm and did not effectively protect their well-being. However, Zimbardo and his colleagues defended the experiment, claiming that the results revealed the enormous influence of situational conditions on human behaviour, and they could’ve not predicted things to play out the way they did.
Informed consent: Prisoners were not disclosed or consented to their home “arrests.” This was due to delayed approval from the police and the researchers’ desire for the arrests to be a surprise. This was a breach of Zimbardo’s own ethics contract that the participants signed.
Psychological harm: Participants acting as prisoners were subjected to psychological harm, including humiliation and distress. One prisoner had to be released after 36 hours due to uncontrollable screaming, crying, and anger outbursts, which he later claimed were fake, and he just wanted to get out anyway. Zimbardo has determined that there were no long-term harmful consequences. Participants attended extensive debriefing sessions and questionaries several weeks, months and years later.
Withdrawal: Participants were not allowed to withdraw from the study despite expressing their desire, which is a severe concern regarding informed consent.
Demand characteristics: Participants’ behaviour may have been influenced by cues or expectations from the experimenters, potentially compromising their voluntary informed consent and the study’s integrity.
Ecological validity: Ecological validity refers to how well studies can reflect behaviour in a real-life situation. This study’s findings may not apply to real-life prison settings because the behaviour of the guards and prisoners, who played a role, may not be influenced by the same factors as in real life.
Selection bias: Selection bias refers to the error in selecting the participant group, not making it random. Some argue that selection bias may have distorted the results due to the ad specifically stating a need for prisoners and guards and how that may have attracted people with specific personality traits.
Results:
The Stanford Prison Experiment, according to Zimbardo and his colleagues, highlighted how people effortlessly adhere to the social roles they are expected to perform, especially when the positions are as highly stereotyped as those of prison guards.
Zimbardo, who served as the prison superintendent at first, even acknowledged becoming so immersed in the role that he ignored to intervene and stop the torture. Later, he claimed that the “social forces and environmental contingencies” of the experiment had caused the guards to misbehave.
Given that it is impossible to replicate the experiment, the experimenters’ conclusions and findings were largely subjective and anecdotal and had low reliability.
According to Zimbardo, two processes can explain the behaviour of the participants:
- Deindividuation could explain the guard’s behaviour: This is a state in which you lose your sense of yourself and personal responsibility after becoming so entrenched in the group’s norms.
- Learned helplessness could explain the prisoner’s behaviour: The inmates discovered that their actions had little impact on how the guards treated them, so eventually, they stopped trying.
The study demonstrates the powerful influence of situational factors on human behaviour, as participants quickly internalized their roles and exhibited extreme levels of aggression and abuse towards their fellow participants who were playing the role of prisoners. These findings shed light on the potential for ordinary individuals to engage in dehumanizing behaviours when placed in certain social contexts.
