Fifty years ago, the aspirations of young men were more or less the same as they are today, but women were different. What women expected, how they saw their lives, their function, their importance, their potential and their future now seem alien to us.

　　 Those differences are fascinating -- and as a consequence, "Mona Lisa Smile,'' which is set in 1953 and dramatizes those differences, is interesting as sociology. In the coming weeks, women in their early 70s may find themselves being asked more than once if the world of 50 years ago was really like that. The ladies I asked all said yes.

　　 Yet the movie comes with a nagging dissatisfaction. Here's a film by Mike Newell ("Donnie Brasco,'' "Four Weddings and a Funeral''), starring Julia Roberts, and the best that could be said for it is that the subject holds interest. "Mona Lisa Smile'' should be moving, but it isn't. We should feel swept up by it, but we don't. There's a spark missing, and where it's missing is in Roberts' conscientious but all too reserved performance.

　　 She plays Katherine, a California bohemian who gets a one-year appointment to teach art history at Wellesley, the great Massachusetts women's college. On the first day of class, Katherine is disconcerted to find out that her students have all read and apparently memorized the textbook. And they're snooty about it, besides. So Katherine has to redo her syllabus just to be able to teach them something they don't already know.

　　 Like Gabe Kaplan on "Welcome Back Kotter,'' Katherine seems to teach only one class and have only four or five students, despite the extras filling out the seats in the lecture hall. Her most formidable challenge is Betty, a ferocious Kirsten Dunst, who has her entire life planned. She's going to marry her boyfriend, then graduate, then have babies and be enormously, ecstatically happy forever. Betty sizes up Katherine, who is unmarried, as a "subversive,'' which was the third-worst thing anyone could be called in the early '50s (after "Communist'' and "fellow traveler'').

　　 The notion of putting a free-spirited Californian into a conservative bastion has potential, but Newell and Roberts don't make nearly enough of the clash. Maybe, if you stared at Katherine for five minutes, you might figure out that she voted for Stevenson and not Eisenhower, but otherwise she looks and acts the same as anyone else on campus. In her essence, she doesn't suggest sexual freedom or ambition or iconoclasm or even -- and this one's a problem -- happiness. She seems dour and not someone the girls would want to emulate.

　　 Katherine wants to teach her students about art and also about life, and although the screenplay (by Lawrence Konner and Mark Rosenthal) doesn't make enough of a connection between the two -- how the freedom of one can inspire freedom in the other -- Roberts effectively gets across Katherine's dismay at her girls' narrow life plans. These are some of the smartest young women in the country,英语影评 but their entire focus is on marriage. Determined to save at least one, she tries to steer a brilliant student named Joan (Julia Stiles) into going to law school.

　　 Stiles, radiant with intelligence, and Dunst, radioactive with bile, are excellent, and so is Maggie Gyllenhaal as Giselle, whose relaxed personality and relaxed morals make her unique in this valley of the high-strung virgins. So long as the movie concentrates on the rituals and mores of 1950s courtship, on period details like skirts and percolators, and on the young women themselves, it's on safe ground.

　　 But Roberts is the star, and her performance, though faultless on its own terms, becomes problematic. Playing a generous, giving teacher, she chooses to act cold. Playing a warm, open personality, she chooses to act covered. The movie does make mention of a judgmental streak in Katherine's character, and any actress would have had to integrate that element, but Roberts plays only that. This makes Katherine not dislikable or wicked, but drab.

　　 The result is that it's hard to believe Katherine could become a beloved teacher or inspire her students, and in the case of "Mona Lisa Smile'' that's the same as saying it's hard to believe the movie. Newell should have seen this coming. The script has scenes of the girls gushing and weeping with thanks at how wonderful Katherine is. Newell should have made sure Roberts seemed just a tiny bit wonderful.