Is There a Dark Side in All of Us?

On 28 April 2004, Philip Zimbardo was in Washington for a conference. The TV was on in his hotel room and photographs of the abuses carried out in Abu Ghraib prison in Iraq by U.S. servicemen and women flashed across the screen. The images are ingrained in our psyche now, but then they were new. Naked men stacked in a pyramid with soldiers grinning alongside. A female soldier leading a prisoner around on a dog leash. Prisoners forced to simulate sexual acts on each other. A prisoner in a hood balancing precariously on a box in the belief he would be electrocuted if he moved. Like millions of others, Zimbardo was deeply shocked by what he saw, but for the professor emeritus of psychology at Stanford University, California, there was a disturbing element of familiarity.

"I had taken similar images myself 30 years earlier," he says. "And by similar, I mean prisoners with bags over their heads, prisoners stripped naked, prisoners made to do sexually degrading activities. It was very disturbing. [The scenes at Abu Ghraib] recreated emotionally the horrible things I not only saw but that I allowed to continue to happen." The images he is referring to came from one of the most infamous episodes in American academic history, the Stanford Prison Experiment -- a study Zimbardo led in 1971 into the psychological and behavioral effects of imprisonment that swiftly descended into scenes of cruelty and degradation.

Zimbardo hoped he would never see Americans behave so abominably again. The shock of the Abu Ghraib scandal three years ago dashed that hope -- and prompted the then-71-year-old to come to the defense of one of those accused of the terrible crimes committed in the Iraqi prison.

What took place on a peaceful Californian university campus nearly four decades ago still has the power to disturb. Eager to explore the way that "situation" can impact on behavior, the young psychologist enrolled students to spend two weeks in a simulated jail environment, where they would randomly be assigned roles as either prisoners or guards.

Zimbardo's volunteers were bright, liberal young men of good character, brimming with opposition to the Vietnam war and authority in general. All expressed a preference to be prisoners, a role they could relate to better. Yet within days the strong, rebellious "prisoners" had become depressed and hopeless. Two broke down emotionally, crushed by the behavior of the "guards", who had embraced their authoritarian roles in full, some becoming ever-more sadistic, others passively accepting the abuses taking place in front of them.

Transcripts of the experiment, published in Zimbardo's book The Lucifer Effect: Understanding How Good People Turn Evil, record in terrifying detail the way reality slipped away from the participants. On the first day -- Sunday -- it is all self-conscious play-acting between college buddies. On Monday the prisoners start a rebellion, and the guards clamp down, using solitary confinement, sleep deprivation and intimidation. One refers to "these dangerous prisoners". They have to be prevented from using physical force.

Control techniques become more creative and sadistic. The prisoners are forced to repeat their numbers over and over at roll call, and to sing them. They are woken repeatedly in the night. Their blankets are rolled in dirt and they are ordered painstakingly to pick them clean of burrs. They are harangued and pitted against one another, forced to humiliate each other, pulled in and out of solitary confinement.

On day four, a priest visits. Prisoner 819 is in tears, his hands shaking. Rather than question the experiment, the priest tells him, "You're going to have to get less emotional." Later, a guard leads the inmates in chanting "Prisoner 819 did a bad thing!" and blaming him for their poor conditions.