The film dumbs down the story while cutesifying it. Scarlett Johansson plays Annie, a gawky Jersey girl just out of college and torn between careers in anthropology and finance. After a chance meeting in Central Park with Mrs. X (Laura Linney) and her runaway boy Grayer (Nicholas Reese Art), she finds herself swept up as a live-in replacement for the preschooler's recently departed nanny. Grateful for a paying opportunity to sort out her priorities, dazzled by the family's sumptuous lifestyle and intrigued by the folkways of their ultra-privileged social set, she signs on.

The adults in his life, however, are almost impervious to improvement. Paul Giamatti is coolly despicable as Mr. X, a potbellied philanderer. Shari Springer Berman and Robert Pulcini, who shared the directing and screenwriting duties, cleverly delay showing the character's face until several minutes after he's introduced; after all, why would a Master of the Universe stoop to look anonymous inferiors such as Annie (and us) in the eye? Mrs. X is a hissy control freak who occasionally allows a tremor of insecurity to penetrate her smug facade, and Linney, expert at channeling multiple emotions simultaneously, does well in the part.

Johansson is so-so as the focus of the film. While she's entertaining as Mrs. X's cowering lackey, stuttering out apologies for imaginary misdeeds, she doesn't project a real rapport with her young co-star Art, who never becomes more than a generic needy kid. Chris Evans (of the "Fantastic Four" films) supplies lukewarm romantic interest as a preppy who takes a fancy to Annie.

Where the film noses into the ditch is the last-reel softening of Linney's character. (This could be considered spoiler territory, although the film itself is so thoroughly compromised by the copout that it's hard to see the harm.) Through an unlikely turn of events, Mrs. X learns what the self-abnegating Annie really thinks of her parenting performance and changes her odious ways, overnight becoming a Carol Brady mom. She ceases feeding her tyke Coquilles St. Jacques and begins eating peanut butter with him straight from the jar while they giggle.

By making the novel's incorrigible mother more sympathetic, Berman and Pulcini soften the material to maudlin, upbeat mush. They'd have done better to keep their appalling antiheroine unapologetic and icy to the end; it didn't hurt "The Devil Wears Prada."