May I interfere and suggest Die Welle? another german movie only it is based on studying how a dictatorship is built (from the aspect of follower raising). The fascinating thing about such experiments is how things get out of control sooner or later. Subjects just "flip out" and get out of control somehow suddenly, even though you can see the escalation in their behavior but you can't really tell when the "fireworks" will start.

Now that I think about it, it's been a long time since I watched a movie of that type...