"The Nanny Diaries," perhaps better titled "The Bonfire of the Nannies," is told from the point of view of a bright college graduate who is accidentally hired as a nanny by a rich Manhattan family. Having studied both anthropology and child development at NYU, she is ideally prepared to study both the X family and its issue, the 5-year-old Grayer X, and the movie is presented like the results of a research study.
It begins, indeed, with its best scene, as Nanny (Scarlett Johansson) visits the Museum of Natural History and explains the dioramas showing lifelike models of Upper East Side natives seen in their natural habitats. One such exhibit comes to life: The Xs. Mrs. X (Laura Linney) having paid her dues by giving birth, now depends on money to see her through the care-giving stage. Mr. X (Paul Giamatti) is a workaholic toiler in the money fields, who is having an affair, which allows his wife to free up valuable shopping time. And Little Grayer has inherited the ingrained traits of his parents; he is acquisitive, aggressive, deceptive and demanding. Also a sad little boy.
Nanny, whose real name is Annie, got the job by saving the life of Grayer after he wandered away from his mom in Central Park. Annie says she is "Annie," Mrs. X hears "Nanny," and concludes that Annie is a nanny, assuming that Nanny is both a job description and a given name. Even the legendary Butcher Drier of Three Oaks, Mich., was called "Ed," not "Butcher," and you won't find a better smoked ham anywhere.
Mrs. X prides herself on buying the best of everything, including nannies. Although most nannies undergo a screening that would make the Transportation Security Administration proud, Nanny's chief qualification seems to be that she's an experienced baby-sitter. Also, of course, that she looks like Scarlett Johansson, and hiring a nanny that looks like a movie star is a status symbol for any family.