The idea behind the film is simple: twenty-six men are selected to take part in an experiment in which they will spend two weeks living in a simulated prison environment. Five of the men are selected to be the prison guards, whilst the remaining participants become prisoners. Barras (Whitaker) and Travis (Brody), who strike up the beginnings of friendship during the selection process, are assigned as a guard and a prisoner respectively.
Simply put, The Experiment is a flawed film through and through. The script is schlocky and feels decidedly inconsistent, whilst the production and acting belie the reason for electing to keep this out of the cinema. Whilst the concept provides ample opportunities for exploration of a number of issues, very few of these are actually explored; rather than psychological drama, things wind up more and more as mindless violence and unpleasantness. The climax of the film too feels decidedly muddled and limp without any real satisfaction.
The saving graces, unsurprisingly, are Brody and Whitaker themselves. Brody's performance is predictably solid, providing some of the film's most emotional and original scenes - a claustrophobic sequence of Brody's Travis in "solitary confinement" presented entirely through night-vision CCTV is one of the film's strongest. That said, Travis' character arc overall feels somewhat flat: he doesn't develop a great deal from start to end, nor does he appear overly affected by some of the ghastly things he has both witnessed, been subjected to and taken part in. Lost's Maggie Grace on generic love interest duty does nothing to improve this, hampered by the stagnant lines she is given to deliver.
It is Whitaker who provides the lion's share of the film's worthwhile material. His performance as Barras is genuinely unsettling, the way we view the character shifting all the time with Whitaker keeping us very much on our toes. Whitaker even manages to make the script work when he delivers it. You'll never be able to hear the word "toilet" the same way after experiencing Barras utter the name of that particular bathroom facility.
The only fathomable reason for watching The Experiment, therefore, is to see the strong performances of Whitaker and Brody, and you can see them as good as they are here in many other, much better films. Without the two big name leads, The Experiment would be utterly forgettable.