On Violence: The Stanford Prison Experiment

Violence can be jolting. External physical harm– an alien object made of steel or wood or flesh coming with brute contact on one’s skin– assaults one’s mind into disbelief. Even with justification, the brain finds the intrusion into one’s psychological and corporal space extremely discomforting. Irrational even.

My interest with violence was brought about by one sleepless night back in highschool. I was following random links on the net when I chanced upon Philip Zimbardo’s Stanford Prison Experiment.


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The Stanford Prison Experiment is a 1971 psychology experiment that simulated life in prison. A group of male college students were divided into two, one group played the role of prison guards and the other group as prisoners. The experiment was cut short after only six (6) days due to increased aggression on the part of the “guards”, coupled with physical and mental deterioration on the “prisoners”. Zimbardo and his group of psychologists also became increasingly entrenched in their roles, acting more like prison wardens than detached researchers.

The psychologist and his team concluded that punitive prison conditions dehumanize prisoners, making them lose their sense of identity. At the same time, they are also dehumanized in the eyes of the guards. This allowed the guards in the experiment, for example, to escalate the punishments since they could not identify the prisoners as deserving of humane treatment.

But perhaps the most chilling implication of their findings was how seemingly normal men can display sadistic behaviours when given certain social and institutional roles.

Decades later, in a 2008 TED talk entitled “The Psychology of Evil”, Zimbardo would connect his findings in Stanford to the tortures inflicted on Iraqi civilians by US servicemen in Abu Ghraib. The official explanation had been that the Iraq incident was the work of a few bad apples. For Zimbardo however, the institutional and situational factors, like the lack of check-and-balance from an external authority, combined with inherent human fallibility resulted to an extremely imbalanced power relations between the US guards and prisoners, which in turn led to horrific abuses on the part of the US servicemen. He also revisits the experiment and his conclusions,  and ties them with events in Iraq in his book “The Lucifer Effect”.


The Stanford Prison Experiment is probably one of the most well-known psychology experiments not just on prison life, but also on man’s capacity to commit violence. In 1992, a documentary about Zimbardo and his team’s work, entitled “Quiet Rage: The Stanford Prison Experiment”, was released.

More than twenty years later, the experiment continues to capture the public imagination. Polish artist Artur Zmijewski recreated the experiment and produced a documentary video of his recreation. The work, aptly called “Repetition”, was shown in the Venice Biennale in 2005. Most recently, a film directed by Kyle Patrick Alvarez (“The Stanford Prison Experiment”) was released in 2015.


(1) Screenshot from the trailer of the 2015 The Stanford Prison Experiment film

(2) Image from the Official Site of the Stanford Prison Experiment.

(3) Still from Zmijewski’s 2005 recreation of the original experiment. Image from here.