In ''Caterina in the Big City," a 15-year-old named Caterina (Alice Teghil) moves from her bucolic Tuscan town with her parents to Rome, where her father, Giancarlo (Sergio Castellitto), has taken a new teaching job. She attends the same school her dad did and becomes friends with the kids of his former classmates, who are now political and social bigshots. Their offspring are an assortment of rich brats who come in two convenient flavors: obnoxious leftists and obnoxious conservatives. But they agree that the new girl is a hillbilly.
As much as the director andco-writer, Paolo Virzi, might try, he can't bring any of these people into focus. The movie is shapeless, too, which is a shame because he really had something with the Jets-Sharks approach to the high-school caste system. But the movie implies far more than it ever explores -- it's not a satire, it's a family drama whose social and political thoughts flicker like a neon sign on the fritz. Alas, sentimentality is the movie's pilot light.
Caterina wants to go to a conservatory for chorale singing, and she's a sweet, obedient creature. The girls who attempt to swallow her up are not. First up is Margherita (Carolina Iaquaniello), a dour mare of a girl, whose room is filled with tapestries and candles and whose mind is full of secondhand political beliefs (her parents are famous academics). She drags Caterina to protest rallies, where the chicest activists know her name if not her cause. (Yes, that's Roberto Benigni bouncing like a pogo stick.) Later, she gets Caterina drunk and gives her a tattoo, which appalls her father, who just happens to have given Margherita a copy of his manuscript to show to her ineffectual mother.
Next is Daniela (Federica Sbrenna), the daughter of one of the higher-ups in the Berlusconi administration. She leads a pack of giggling, shrieking girls who tear through the city's department stories and regurgitate their parents' right-wing beliefs (at one point Daniela leaps up to sing a fascist anthem). Somewhat inevitably, she is also a flirt, daring to taunt her driver. But she's generous, too, setting up Caterina with her smitten cousin, Gianfilippo (Martino Reviglio), who also likes classical music. We know this romance is doomed when, on the way to meet his socialite mother, Caterina asks whether Gianfilippo approves of her skirt, and he says, ''Yes, but that hair clip?"
In another set of hands, ''Caterina in the City" might have been a rich generational portrait of modern Italy, but Virzi's style is too jittery to dramatize his perceptions convincingly. From the appearance of Benigni to Castellitto's grating neurotic performance, the movie feels overcaffeinated.
Caterina is the movie's source of calm, though her biggest problem is that the film bearing her name hardly knows how to make her interesting. Teghil is certainly spirited, but Virzi doesn't give her character a spine or a brain or a real personality. And she's the one person in the movie he actually seems to like.
Wesley Morris can be reached at email@example.com.