Back in 1971, Philip Zimbardo, a Stanford psychology professor, set up an experiment that quickly and now famously went awry. Here, Zimbardo had undergraduates play the role of prisoners and prison guards in a mock prison environment. Meant to last two weeks, the experiment was cut short after only six days when, as The Stanford Prison Experiment web site puts it, the guards "became sadistic and [the] prisoners became depressed and showed signs of extreme stress." For Zimbardo, the way things played out says a lot about what happens when good, average people are put in bad situations. And it speaks to how torture scenarios, like those at Abu Ghraib, become possible. (For more on the parallels between the prison experiment and the torture in Iraq, you may want to check out Zimbardo's recent video-captured talk at Googleplex.
Below, we've posted a video that offers a quick version, with original footage, of how the prison experiment went down. If you're interested in understanding what he calls the "Lucifer Effect," the title of his new book (which, by the way, was just reviewed by Martha Nussbaum in the Times Online), then it's worth your time.