Little Miss Sunshine (15) <!-- none onestar twostar threestar fourstar fivestar -->

A comic ray of light

I wonder why it's a movie principle that dysfunctional American families have to go on road trips in order to find out about themselves. Couldn't they do the job more conveniently at home? We know the way to healing and reconciliation is a "journey", but does it have to be an actual journey? In the modest and endearing comedy of disappointment Little Miss Sunshine, the reasons for getting the troubled suburban family, the Hoovers, out of the house and on to the road are tenuous to the point of absurdity, yet by the end of their bumpy ride you feel glad for having joined them: they've got on each other's nerves without, miraculously, getting on ours.

At its root is a sense of headstrong American competitiveness, personified in the not-very-likeable character of Richard Hoover (Greg Kinnear), a motivational speaker whose "refuse to lose" philosophy is not winning friends or influencing people, in a big way. We first see him doing his nine-step programme for success on stage, then the camera draws back to reveal a piteous handful of listeners. He's also trying to keep a book deal alive, and his increasingly plaintive phone calls to a business partner suggest that his own steps programme is in tragic reverse. Or let's say tragicomic, for there can be no job more embarrassing to fail at than that of success guru.

His wife Sheryl (Toni Collette) is trying to keep things together, though the combination of Richard's pomposity and her children's eccentricity is making it almost impossible. Her seven-year-old daughter Olive (Abigail Breslin), a podgy, bespectacled munchkin, is determined to compete in the Little Miss Sunshine beauty pageant, and her teenager Dwayne (Paul Dano) has retreated into silence and a deluded obsession with Nietzsche's übermensch (talk about competitive!).

As if that weren't enough, Grandpa (Alan Arkin) has been kicked out of his retirement home for snorting heroin ("the intervention was a fiasco") and her brother Frank (Steve Carell), a Proust scholar, has just slashed his wrists over a stupid love affair - and now must be kept on suicide watch by the family. On his first night he shares a bedroom with Dwayne, who scrawls, in mute Holly Hunter-style, on a notepad: YOU WON'T TRY TO KILL YOURSELF, WILL YOU?

With deviance and daffiness stacked so high the movie might just have toppled into whimsy, or worse, into the sort of chaotic dysfunction that has recently capsized director Todd Solondz. Instead, the husband-and-wife directing team of Jonathan Dayton and Valerie Faris, working from Michael Arndt's script, steer a very canny line between comedy and realism.

You might balk at the idea of the Hoovers squeezing into their clapped-out VW van to take Olive to the beauty contest; once they're on the road, however, the observation of the family dynamic has a truthfulness that's sometimes poignant, sometimes hilarious (and sometimes both at once). There's one especially awkward scene in a diner where Olive says sorry to a waitress, and her father rebukes her: "Apologising is a sign of weakness." Suddenly we understand why he's a lousy motivator. Later, Olive asks her grandfather if he loves her, a question that an ordinary movie would turn to mush. Here, the old man says that he loves her, not because she has brains or personality, but "because you're beautiful". The line feels wrong, and yet it's exactly what the little girl wanted to hear.

The script continually succeeds in wrongfooting us, a tactic underpinned by a full house of terrific performances. Arkin, playing the most lecherous old goat since Albert Steptoe, relishes his every moment - I loved it when he barked out an order for porno mags at a highway convenience store: "Make sure it's the nasty stuff". Carell proves himself a fine actor, not just a comic, and his acceptance of the farce that has blindsided him ("I was the No 1 Proust scholar," he keeps reminding himself) is moving as well as funny. The same goes for Kinnear and Collette as the Hoover parents, the latter one of the best in the business of put-upon mothers, the former effecting an extraordinary (because believable) turnaround from oafish self-importance to a model of contrite decency.

The way Kinnear's expression passes from bemusement to alarm as he watches the kiddie beauty pageant unfold is tellingly done: the Little Miss Sunshine contest turns out to be a grotesque parade of prepubescents gurning and cavorting in bright cockatoo make-up, a snapshot, if another one were needed, of What's Wrong With America.

As Olive prepared to do her talent spot, I felt quite close to panic at the prospect of her humiliation, not least because Breslin's performance had been the heart and soul of this unpredictable movie: her artless enthusiasm, affectionate nature and blind belief in her own talent are all impeccably detailed.

Cute children are regularly a bane of modern movies because their cuteness is so clearly the product of an adult imagination; Breslin offers a character portrait so apparently unselfconscious as to be almost staggering, and delivers the film's payoff with a mixture of delight and queasiness one might find difficult to parse. Innocence has survived, you feel, in the most ambiguous way possible. This debut movie slyly keeps us guessing until the end, and if it touches a nerve it may also bring a tear to your eye.