Stanford Prison Experiment and Its Relationship to Ethical Psychological Research

You may have heard about the infamous Stanford prison experiment. Why is it still important and relevant today? The Stanford prison experiment was a social psychology study in which college students became prisoners or guards in an environment controlled by Philip Zimbardo and funded by the U.S. Office of Naval Research. 

Why is the experiment so infamous? 

In the 12-week experiment, 24 male college students were examined for psychological health and randomly assigned to either the prisoners or the guards group. For this experiment to mimic a realistic situation, the “prisoners” were arrested at their homes without warning, and were placed in cells, given uniforms, and given numbers to identify each prisoner. As a result, the “guards” began behaving sadistically, inflicting constant humiliation and harm on the prisoners. This experiment then derailed the “prisoners” to be dehumanized and be obedient towards the “guards”.  Several “prisoners” showed signs of extreme disturbance, and even with the right to withdraw from the experiment, the immense and tension-filled simulation made it psychologically challenging to exercise the right. However, because of the concerns about the increasing emotional and psychological trauma on the prisoners, the simulation ended in an abrupt 6 days. 

In conclusion, this experiment has demonstrated the power of certain situations to alter human behavior dramatically and rapidly. This experiment highlights how even the ‘morally good’ and ‘normal’ people can do evil acts when situations force them in that direction. 

What relationship does the experiment have with ethical psychological research? 

Zimbardo proposed that there were two reasons behind the ethical and ‘morally wrong’ behavior of either group, the prisoners or the guards. He believes that deindividuation could explain the ethical behavior of the participants, especially the guards. Deindividuation is when you become so “immersed in the norms of the groups that you lose your sense of identity and … responsibility.” The guards may have been sadistic because they did not feel what happened was down to their character; instead, they lost their identity because of the identical uniform they wore. 

He believed that this experiment, alongside research, showed that learned helplessness could reason for the prisoner’s submission to the guards. It is an underlying cause of depression, and causes the individual to continuously face a negative and uncontrollable situation. This makes the individual try to improve their situation, even when they have the ability and right to do so. After the experiment, Zimbardo conducted his interview with the participants, and some responses were: 

“I made them call each other names and clean the toilet with their bare hands. I practically considered the prisoners cattle, and I kept thinking I had to watch out for them in case they tried something.”

“Acting authoritatively can be fun. Power can be a great pleasure.” 

Even from this, most guards found it difficult to believe the sadistic and brutal self they had become to other college students. Many had voiced that they hadn’t known this part of their side had ever existed and were capable of such things. 

The escalation of aggression and abuse by the guards could be seen as being due to the positive reinforcement they received from fellow guards and how good power had made them feel, in terms of adrenaline and excitement. 

In 1973, the American Psychological Association (APA) investigated the ethical aspects of the prison experiment and decided that it met the ethical standards and morality that were in place at the time. However, as the world evolves, the ethical standards evolve as well. The study has received so many ethical criticisms, including the lack of informed consent from the prisoners, because the results were unpredictable. This experiment became a breach of ethics, even in Zimbardo’s contract, which all the participants signed beforehand. 

For example, one of the most prominent and critical ethical criticisms came from Eric Fromm in 1973, who directly questioned and addressed the unethical nature of the harsh criticisms imposed on the prisoners. He highlighted the fundamental question of whether the potential results gained from the experiment justified its harm to the prisoners, psychologically, mentally, and emotionally. 

Although guards were explicitly instructed not to physically harm prisoners at the beginning of the prison simulation, they were allowed to act on feelings such as boredom, frustration, and powerlessness among the inmates. 

Another example of the criticism faced by Zimbardo. Zimbardo has mentioned his double role as a “prison superintendent” and a principal investigator. By actively participating in the experiment, he had often blurred the lines between a ‘uncontrolled control variable’ and an investigator. His immersion in the role could have compromised his ability to maintain a detached, professional, and ethical oversight of the study and to recognise and respond appropriately to all of the escalating harm and deteriorating health of the prisoners. 

These conditions, created within the simulated experiments, raised serious ethical questions about the responsibility of the researchers and Zimbardo for the well-being and health of their participants. 

Reference list

American Psychological Association (2004). Demonstrating the Power of Social Situations via a Simulated Prison Experiment. [online] American Psychological Association. Available at: https://www.apa.org/topics/forensics-law-public-safety/prison.

Cherry, K. (2023). The Stanford Prison Experiment. [online] Verywell Mind. Available at: https://www.verywellmind.com/the-stanford-prison-experiment-2794995.

Lurigio, A.J. (2023). Stanford prison experiment | EBSCO. [online] EBSCO Information Services, Inc. | www.ebsco.com. Available at: https://www.ebsco.com/research-starters/health-and-medicine/stanford-prison-experiment.

McLeod, S. (2023). Stanford Prison Experiment: Zimbardo’s Famous Study. [online] Simply Psychology. Available at: https://www.simplypsychology.org/zimbardo.html.

Pass, J. (2025). Simply Put Psych. [online] Simply Put Psych. Available at: https://simplyputpsych.co.uk/psych-101-1/criticism-of-the-stanford-prison-experiment.

Tikkanen, A. (2022). Stanford Prison Experiment | History & Facts. In: Encyclopædia Britannica. [online] Available at: https://www.britannica.com/event/Stanford-Prison-Experiment.