00:00In 1971, a professor built a prison in the basement of his university.
00:03He locked a group of college students inside.
00:06Six days later, the experiment was shut down in a panic.
00:09And those six days wrote a conclusion into psychology textbooks all over the world.
00:14Until someone dug out the old recordings.
00:16Let me tell you how the story was originally told.
00:19In August 1971, Stanford psychology professor Philip Zimbardo built a mock prison in the
00:24basement of the psychology department.
00:26He recruited a group of college students and drew lots to decide who would be guards and
00:29who would be prisoners.
00:30He planned to observe them for two weeks.
00:33These students had all been screened, mentally healthy, no violent tendencies.
00:37Just ordinary young people.
00:39Then things spiraled out of control.
00:41The guards began to abuse the prisoners, stripping them, replacing their names with numbers, waking
00:46them in the middle of the night, spraying them with fire extinguishers.
00:49Some prisoners had breakdowns.
00:51Some begged to leave.
00:53The two-week experiment was stopped on day six.
00:56Zimbardo's conclusion became one of the most widely spread phrases in 20th century psychology.
01:00It's not that people turn evil, it's that the environment turns them evil.
01:04Put an innocent person in a certain role, give them power over others, and they will start
01:07to abuse it.
01:08That conclusion was huge.
01:10It went into psychology textbooks all over the world, usually without any criticism.
01:15It was made into a film, a documentary, written into books.
01:18It was even cited in the U.S. Congress.
01:21When prisoner-abuse scandals broke during the Iraq War, this experiment was pulled out
01:24again and again as the explanation.
01:26For half a century, it was our most used key for understanding human evil.
01:30And the whole story stood on a premise nobody ever went back to check, that the guards became
01:35monsters on their own.
01:36But some people had doubts from the very start.
01:38In April 2018, a French scholar and filmmaker named Thibaut Lutexier published a book called
01:44The History of a Lie.
01:46Here's what he did, Stanford University had released Zimbardo's full archives, and he
01:50read them, one file after another.
01:52Among the archive were tape recordings.
01:54One of them captured a conversation between Zimbardo's assistant, the man who played the
01:58warden, David Jaffe, and one of the guards.
02:01The guard said, I'm really not that tough.
02:04Jaffe replied, so you have to try to be tough.
02:06The guard said, yeah.
02:08I'm not sure I can.
02:10Then came Jaffe's key line, tough means you have to be firm.
02:13You have to intervene, you have to take action.
02:16Whether this experiment succeeds or not depends on your behavior, 10 minutes at a time.
02:20Because our goal is to make this look like a prison, and a lot of that depends on the
02:23guard's behavior.
02:24That recording was later posted online by Stanford itself.
02:28And now, if you look at how.
02:30Zimbardo told the story, you'll notice something subtle.
02:33Every time, he started from Sunday, August 15th, 1971, the day the guards started abusing
02:38the new prisoners.
02:39Told that way, it sounds like they turned evil on their own.
02:42But the more honest version would start a day earlier, the day before, the guards held
02:46a briefing meeting.
02:48That one-day difference changes the whole nature of the thing.
02:51If the guards turned evil on their own, the experiment proves something about human nature.
02:55If the guards were coached into being evil, then it just proves one thing, that a person
02:59can be persuaded to do bad things.
03:01And those two things are worlds apart.
03:03The next evidence came from the participants themselves.
03:06The cruelest guard was named Dave Eshelman, known for his southern accent and inventive
03:10cruelty.
03:10He had studied acting from high school through college.
03:13And he admitted, the accent was fake, and so was the cruelty.
03:17He said, I saw it.
03:19As an exercise in method acting.
03:21My only goal was to help the experiment succeed.
03:24On the other side, the famous prisoner who had a breakdown, his name was Cripe, later said
03:28his collapse was also faked.
03:30And there was another recording from day three.
03:32Zimbardo told his staff, interesting, yesterday two people came to me and said they wanted to
03:36leave.
03:37I said no.
03:38There are only two ways to leave, a medical emergency or mental breakdown.
03:43Then he said, I think they really believe they can't get out.
03:46And there's an even harder test, doing it again.
03:49Psychologists Haslam and Riker ran a similar experiment on the BBC, with two conditions changed,
03:54the guards received no instructions, and the prisoners could leave at any time.
03:57The result was almost the opposite of Zimbardo's.
04:00The prisoners didn't break down, they united and won extra privileges from the guards, while
04:04the guards became more passive and withdrawn.
04:06Same basement, same.
04:08Role assignment.
04:10The only difference was whether someone was coaching on the sidelines.
04:13They tried to publish their results in the British Journal of Social Psychology.
04:17According to Riker, Zimbardo wrote privately to the editor, trying to block the publication
04:21and accusing them of fraud.
04:22It was published anyway, with a comment from Zimbardo, in which he called the study fraudulent.
04:27Now, I have to be fair here, or this becomes a one-sided trial.
04:31Zimbardo himself responded publicly to all these accusations, point by point.
04:36His core defense, the experimenters never gave the guards formal, detailed behavioral instructions.
04:41Whether that holds up depends on how you define, formal, and, detailed.
04:44And the academic world still has no unified verdict.
04:48Some think the experiment is completely discredited.
04:50Others think its core insight still has value, just over-packaged.
04:54I'm telling you the version with the strongest evidence, not a final judgment.
04:58And don't reduce Zimbardo to a villain.
05:00He and psychologists of Milgram's generation were
05:03driven forward by the shadow of World War II.
05:06The question they truly wanted to answer, why did ordinary Germans do those terrible things?
05:11That's a vital question.
05:12A whole generation spent their careers on it.
05:15He found the wrong answer, but he asked the right question.
05:18Except one thing can't be excused by asking a good question.
05:21The recordings show that while the experiment was running, he knew the guards were being coached.
05:25And for 50 years he told the world the version where the guards turned evil on their own.
05:30That wasn't a misjudgment, that was a deliberate choice.
05:33So what does this experiment actually prove now?
05:35The original conclusion, put good people in a bad environment, and they turn bad.
05:39After the recordings, the supported conclusion becomes something else, an authority, if it
05:44wants to see cruelty, can persuade people to be cruel.
05:47Those two sentences sound similar, but they're worlds apart.
05:50The first says, no one is responsible, the environment did it.
05:54The second says, someone is responsible, the one giving the orders.
05:58Social psychologists now say obedience is not natural, not inevitable.
06:03Obedience is organized.
06:04So in that tape, there's no devil.
06:07There's just a man who wanted the experiment to succeed, and another man who didn't want
06:10to disappoint him.
06:11And that's the truly uncomfortable part, you don't need a devil to do those things.
06:16So one last question, why was this experiment believed for 50 years?
06:20I think the answer isn't in the methodology, it's in us.
06:23Because the story it told was one we wanted so badly to believe.
06:26The bad things we've done can't really be counted against us, it was the environment,
06:30the atmosphere, the position we were in.
06:32It's a free pass written for everyone.
06:34Who wouldn't want that?
06:36In 2018, the recordings were released.
06:39Two years earlier, in 2016, a study examined 24 popular psychology textbooks and found they
06:44were generally inaccurate.
06:46In describing this controversial topic, readers may have been misled without knowing it.
06:50Today, the Stanford prison experiment is still in many textbooks.
06:54But before you rush to judge those guards, remember, they weren't testing anything.
06:58They were being told, line by line, by someone they trusted, whether this experiment succeeds
07:02depends on you.
07:03If you've ever had a boss pat you on the shoulder and say, you know what I mean, then
07:07you know exactly how much weight those words carry.
