Fourth in a series about the national pavilions at the Venice Biennale.

In 1971, Stanford University social psychologist Philip Zimbardo launched a famous experiment. He created a fake jail, randomly designated some student volunteers as "prisoners" and others as "guards," locked the doors, and sat back to observe results. They were nasty: Behavior became so brutish that the two-week project had to be called off after six days.

Ever since then, there's been plenty of debate about what the results signify. Polish artist Artur Zmijewski, one of the most radical and controversial figures on the European scene, has a novel take on them. His new 46-minute film, called "Repetition," suggests that Zimbardo's experiment, which had as much intuition as strictly scientific method behind its design, may have had the makings of a work of art.

In "Repetition," Zmijewski explores that hypothesis by repeating the Stanford experiment in front of hidden cameras, with hard-up Poles standing in for American students. For the past week, his film has been screening every hour, on the hour, in a theater inside the Polish pavilion at the Venice Biennale, the world's oldest celebration of contemporary art. More than almost any other work here, the film is absorbing and perplexing, appealing and troubling.

Which means that Zmijewski had it right: There's art in them thar cells.

As in the original experiment, the Polish prisoners and their jailers are perfectly aware of the artificiality of the situation: No one has real-life authority over anyone else, the guards' nightsticks are just for show, and anyone who wants to can withdraw at will (though the $40 daily fee gives the subjects extra incentive to stick it out). Despite that awareness, all the participants seem to do their best to carry out their jobs, as they imagine them according to whatever vague instructions they've been given: The guards try to enforce order, and the prisoners at first obey and then resist, almost as though this dynamic is built into the power situation that they're living through.

There are no layabouts in this project -- no participants happy to ignore their assigned roles, twiddle their thumbs and collect their daily pay. All the prisoners, for instance, seem willing to use numbers to refer to one another, as they've been told to do, even though there's nothing stopping them from using names.

Strangely, that uniform acceptance of the terms of the assignment makes it somehow less convincing as a real, in vitro view of human life: At first, at least, you feel that all the players know they're playing roles, and that they can't be bothered to resist the game. For a while, the piece has all the genuine urgency of reality TV -- that is, very little. We know we're looking at artifice, and the prison-dwellers know they're constructing it.

There's even an interesting parallel between our experience, as viewers, and theirs. We know that we can leave the cinema at any time when the film gets dull or hard to take, as it often does, and yet most of us stay, because of a kind of social contract built around the making and viewing of art.

In the simulated prison, however, artistic decorum soon gets left behind. The "game" achieves a momentum of its own, so completely wrapping up its players in its dynamic that it starts to touch them at the core. Guards get more brutal and controlling: The disobedient are put in solitary; all heads are shaved. At this point a few prisoners, rather than simply seeing all this as annoying play that they can bear with for as long as it takes, see it as a genuinely evil situation and quit the "experiment" for good. The remaining prisoners practice escalation: One ringleader pees in someone's soup, then later throws a bucket of urine through the bars of his cell.

At this grim moment, we viewers may be tempted to walk out, too.

But this is where Zmijewski's artwork starts to deviate from the course taken by Zimbardo's experiment. Things don't continue to break down, as they did at Stanford. In Poland, the man picked to play "warden," who had been tightening the screws on his charges all along, looks into his heart and decides that he can't bear what is going on. He calls a meeting with the prisoners to talk things over. They decide, as a group, to drop the evil game, exchange their real names and walk out on Zmijewski's project.

You could take home a cheery message from all this: Zimbardo's view, that a power relationship can bring out the beast in any one of us, is simply wrong -- people can push back, refusing to follow rules society has set for them. But I think Zmijewski's film argues for a more complex reality: Pseudo-scientific studies of human behavior won't get you very far, because they turn out not to be repeatable. All you can do is set up a situation and stand back in awe as people run with it. There's no predicting human nature, or drawing rules from it; there's just describing its peculiarities.

The question "what happens if" is shared by science and art -- but artists care more about asking it than finding answers. When it comes to people's inner lives, art's simple description may give more insight than the conclusions drawn from experiments do. Or rather, with humans, what looks like an experiment may turn out to have the unpredictability of art. Humans are so artful, so good at writing and rewriting scripts, that there's no hope they will follow any single one for long.

In all his work, Zmijewski begins by establishing certain bizarre preconditions: He organizes a choir of the stone-deaf, then asks them to sing Bach; he asks the able-bodied to function as the arms and legs of amputees; he takes people to a Nazi death camp and gets them to play tag in the gas chamber. Then he records the behaviors that result. Come to think of it, that makes him sound rather like a scientist, after all -- though maybe a mad one.

Artur Zmijewski's "Repetition" looks like a TV stunt until things turn grim.Artur Zmijewski's "Repetition" redoes the famous Zimbardo experiment, in which participants were designated as guards or prisoners and observed for several days.