In this series, I dig a little deeper into the meaning of psychology-related terms. This week, we’ll look at the Stanford prison experiment.
The Stanford prison experiment was a social psychology study carried out at Stanford University in 1971. Researchers randomly assigned Male student volunteers to be either “prisoners” or “guards” in a mock prison set up in a building on the university campus. The study excluded potential participants with criminal backgrounds or psychological/medical issues. The goal was to examine how people were affected by the perception of having power. Funding came from the U.S. Navy.
The Mock Prison
The participants received $15/day. The researchers informed them in advance that they could leave at any time. The “prisoners” were picked up at their homes, blindfolded, taken to the police station and “booked,” and then taken to the “prison,” charged with armed robbery. Upon arrival, they were stripped, deloused, and given prisoner uniforms marked with identification numbers.
Wooden batons were given to the “guards” as symbols of power. They also received mirrored sunglasses to make it harder for prisoners to read them. Both “guards” and “prisoners” were instructed to call the “prisoners” by their ID numbers rather than their names. The “prison” involved 3-man cells and a closet designated for “solitary confinement.”
The lead investigator, Philip Zimbardo, acted as the “superintendent” of the “prison”, and told the “guards” to exert control over the “prisoners” and strip away their individuality. A research assistant acted as “warden.” Parts of the study were filmed.
Things start to get ugly
By the second day, things started going downhill. Zimbardo described one “prisoner” who started to “act crazy, to scream, to curse, to go into a rage that seemed out of control.” He was released from the study.
Things just got worse, and Zimbardo estimated that about 1/3 of the “guards” became sadistic, with behaviours like:
- the “guards” forced “prisoners” to use buckets in their cells rather than going to the toilet
- “guards” forced some “prisoners” to sleep on concrete or to go naked
- one “prisoner” said he was on a hunger strike, and the “guards” forced him to go into “solitary confinement”
- certain “prisoners” were given basic privileges to further demoralize those who didn’t get the same privileges
- “prisoners” were forced to do pushups while guards stepped on their backs
The study was planned to last 2 weeks, but it was stopped after 6 days when Zimbardo’s girlfriend, a psychology grad student, pointed out what a disaster it was. By that point, three “prisoners” had already been removed early from the study.
Zimbardo claimed that the study showed that the participants had internalized their roles and that behaviour was influenced by the situation rather than individual personality traits. He believed that deindividuation strategies like using “prisoner” numbers rather than names contributed to this.
As a consequence of this study, the American Psychological Association developed ethics guidelines requiring institutional ethics review board approval studies are conducted.
Ethically, this study is full of problems. Setting that aside, though, it’s disturbing how readily people will act abusively towards others. The element of deindividuation made me think of the Holocaust (although obviously on a much different scale) – it”s easier to dehumanize a number than a person.
The Attica Prison riot in New York State happened in the same year, and it makes me wonder how much the same elements that were observed in the Stanford experiment came into play in the guards’ treatment of prisoners leading up to the deadly Attica riot.
Zimbardo’s Stanford Prison Experiment official website contains his description of the events that occurred, and contains photos and some videos (along with quite a bit of advertising). The experiment was the subject of the 2015 film The Stanford Prison Experiment.
What are your thoughts on the dynamics that emerged in the Stanford study?
The Psychology Corner has an overview of terms covered in the What Is… series, along with a collection of scientifically validated psychological tests.
Ashley L. Peterson
BScPharm BSN MPN
Ashley is a former mental health nurse and pharmacist and the author of four books.