In peers: "Involuntary"

A young girl is brought into a classroom, and asked by her teacher to pick out the longest of two parallel lines from a series of flashcards. In the first two instances, the girl picks out what is evidently the longest, only for her classmates (operating under pre-arranged instructions) to contradict her; on the third pass, her judgement suddenly called into question, she plumps for the shorter of the two. This documentary-like episode comes a good 20 minutes into the Swedish director Ruben Östlund's second feature Involuntary, yet in some ways it's the code to cracking the meaning of this disarmingly singular film.

Here are snippets from five separate dramas that collectively serve to illustrate a particular thesis - and yes, the influence you can sense is that of Michael Haneke's earlier works. Outside of the schoolroom experiments, we're introduced to a pair of peroxide-blonde Paris Hilton clones, gearing themselves up for a fall while out on the town one night; a pack of roughhousing businessmen, egging one another on to more outlandish behaviour during a stag weekend; a middle-aged actress obliged to share an uncomfortable coach journey with civilians who won't stop pestering her about her past work; and a retired paterfamilias who, for the benefit of a family gathering, continues to smile on even after being hit in the face by a misfiring firework.

The theme (arthouse spoiler alert!) is peer pressure - the relationship between the individual and the group, those questions of personal and social responsibility drilled into us from a very early age - and Östlund's control is exemplary. Like Haneke, he watches his characters with a clinical detachment, locking off his camera, sometimes even going as far to obscure their faces and other distinguishing features altogether, as though they were literally under surveillance. Again, as with Haneke, the film has a correctional intent: we're not only shown that bad things happen whenever the good do nothing, but that it can even happen when the good do try to impose themselves. (See the ongoing difficulties of the schoolteacher faced with reporting a colleague she's observed being abusive towards a student.)

Yet Östlund's fingers are used just as often to tickle as wag. There's a playful edge to these social variations that suggests the mischievous schoolboy logic of Lars von Trier's The Five Obstructions wedded to the fly-on-wall pranksterism of Ashton Kutcher's Punk'd: some of these performances and interactions, the film's choicer moments, are too good not to be true in some way. (Ten years ago, Involuntary would surely have emerged under the Dogme banner; the horrendous fireworks display in particular is very Festen.) Instructional enough to be employed as a teaching device, yet sufficiently open in form and mind to generate lively discussion afterwards, it's surprisingly sparky, distinctive and fun as ethics lessons go - though it forms part of the rules of engagement that viewers be left free to disagree.

Involuntary opens in selected cinemas today.