The Experiment That Went Too Far Stanford University, California August 1971 Two weeks, it was supposed to be. It was six days.

Stanford psychology professor Dr. Philip Zimbardo wanted to answer one simple question: Does prison make people cruel, or are they cruel when they get there?

So, he set up a fake prison in the basement of Jordan Hall on the Stanford campus in August 1971 to find out. He chose 24 healthy, normal college students, randomly assigned them to two groups — half were to be guards, half were to be prisoners — and told them to live their roles for two weeks.

There was no script supplied. Nobody was told what to do. He wanted to see what would happen.

It was not what anyone had anticipated.

On the morning of August 14, 1971 real Palo Alto police officers came and picked up the student prisoners at their real homes, handcuffed them, searched them and drove them to the basement of Stanford. They were stripped and given a numbered smock to wear and a chain was bolted round one ankle. They called them by numbers not by names.

The guards wore uniforms, wooden batons and mirrored sunglasses.

Within hours, everything was different.

The guards woke prisoners up for pointless headcounts at two and three in the morning. They made them do push-ups as a punishment. They refused bathroom breaks. They had prisoners clean toilets with their bare hands. No one had told them to do any of this shit. The prisoners invented these tasks almost eagerly, as if the uniform had released something that had lain dormant within them, waiting for permission.

The prisoners fell apart just as fast. One student was forced to be released, breaking down screaming within 36 hours. Some developed rashes from stress. Some refused to eat. They did not think of themselves as volunteers at a university. They started to view themselves as genuine prisoners with no hope of escape.

Zimbardo himself got caught up in the drama. He stopped thinking like a scientist watching an experiment and began to think like a prison superintendent running a facility. He made decisions to save the experiment, not the people in it.

It took a woman to halt it.

On day five Christina Maslach, a graduate student in psychology, and who would later become Zimbardo’s wife, visited the basement. She saw students being led to the toilet with bags on their heads. She saw guards mocking and humiliating prisoners who had committed no crimes. She turned on Zimbardo and told him that he was doing something wrong and that he had to stop it now.

She was the only one of all the visitors that week who had that feeling.

The next morning Zimbardo shut it down. Day 6 of a 2 week study.

The experiment became one of the most famous and most controversial studies in the history of psychology. It seemed to show that ordinary people in positions of power over others will abuse that power almost automatically if given the right uniform and the right circumstances.

But the criticism followed. Later researchers pointed out that the guards were subtly conditioned to be tough from the start. Some participants admitted that they were playing a role and were deliberately overplaying their part. The science was challenged. The ethics were damned. No university in the world would sanction that study today.

It’s not the science, it’s not the debate that stays with you. It’s the picture of the normal college kids—kids who had passed every psychological test and had no history of cruelty—who spent less than a week in a basement and became people their friends wouldn’t have recognized.

In that basement, nobody was born cruel. They just put on a uniform and got power over another human being.

That would do.

Stanford Prison Experiment (SPE) · August 14-20, 1971 ( Directed by Dr. Philip Zimbardo · Stanford University, California: Closed after 6 days. Never again.