Kyle Patrick Alvarez’s The Stanford Prison Experiment (opening Friday at the Main Art Theatre) is a kind of drama-documentary about a real life experiment that, well, went so right it went wrong. It’s based on a true psychology experiment at Stanford in 1971 with a theme you’re probably familiar with. Throw a bunch of people into opposing power relationships and see what happens. In this case Dr. Philip Zimbardo (Billy Crudup), the psychologist, cooked up an experiment whereby a bunch of students would be paid $15 a day to stay in a replica prison for two weeks. Some were chosen as guards, others prisoners. The students at first take a light-hearted approach thinking there might be some realism but, hey, this is a controlled university experiment - with explicit instructions of no physical harm - taking place on campus, so what could go wrong? As you might suspect, plenty. Well, actually, in scientific terms, nothing. In fact, the students who play the guards take their roles so seriously the experiment is a smashing psychological success in terms of what it finds about the excesses of human nature. The jail - actually a small cordoned off hallway in the bottom of a university building - soon descends into the roughest prisoner boot camp you might imagine. The prisoners have the proverbial smiles on their faces wiped off in no time. An insubordinate prisoner is forced to strip naked. Others are literally thrown in “the hole” (a dark closet). The hands-off approach is ignored and physical fighting breaks out with the guards using their night sticks to keep the inmates in line. When one of Zimbardo’s associates suggests intervention, he says, “No, let the guards figure it out.” A rebellion ensues and a riot takes place within a hundred square feet. The guards, especially one played exquisitely by Michael Angaramo as a kind of badass southern sheriff (think: “You in a heap of trouble, boy!”), become almost psychotic in their demands for obedience and eventual enforced depravity. The experiment, however, goes off the rails when the prisoner students think this is more than what they signed-up for and demand out. But they can’t leave, except in one or two extraordinary cases, where the first released inmate threatens legal action. Zimbardo himself takes on the role of authoritarian warden, calling the basement cell block “my prison.” When the guards try to force the prisoners to sodomize one another Zimbardo finally intervenes and calls a halt. The two week experiment ends after six days. Based on true events none of the participants suffered long term harm. Zimbardo found the research (the movie is based on his book The Lucifer Effect) integral to an understanding of authority, power relationships and how good people turn bad. It’s similar to the earlier Milgram electric shocks experiment at Yale. This is all fine and the movie is tautly paced and has great performances by a rising group of young actors including Ezra Miller, Johnny Simmons, and Tye Sheridan. But if the film follows the experiment so closely (and Zimbardo consulted on it) I wonder how Zimbardo got away with creating a real life dungeon, depriving citizens of their rights. In the end, though, Zimbardo is lauded for his depth of research into how ordinary people can become tyrants. But didn’t anyone question how he himself became one?