LET'S BE HONEST HERE. One reason I'm glad Kirsten Dunst is growing up is that I'd like to be able to enjoy watching her onscreen without feeling depraved. I've got no doubt that I'm succumbing to talent, but I think Albert Finney is pretty great, too, and I know I wouldn't get much zing from watching a skimpily dressed Finney wash cars on a hot summer day--the most eye-popping scene in Dunst's Bring It On . I'm also closer to his age than hers, and, if only for my own middle-aged dignity's sake, I could wish this weren't a movie era when one man's favorite actress is another man's jailbait. It's just awkward, you know?

Thanks to a cult of youthfulness that goes hand in raincoat with a frisson of erotic taboo, actresses who need fake IDs to buy beer are bigger box-office draws than they have been since D. W. Griffith was working off his hang-ups about imperiled maidenhood. Last winter, it seemed like some kind of turning point when Pepsi had Bob Dole say "Easy, boy" during Britney's hubba-hubba Super Bowl commercial; that's when American men officially got permission--from a gen-u-wine hero, no less--to ogle teenage girls.

Then again, the paradox is that some of these cuties are also fantastically talented, and the hell with my dignity. Even in an anorak, Dunst would be something special. She's been in movies ever since she turned up in New York Stories at the ripe old age of six, and most of them have been fairly silly. That's one reason it's taken people a while to recognize that she's amazingly good in them, and another is that Dunst never signals that she's up to anything unusual. She grasps each role so completely on its own terms that her behavior is utterly idiomatic; only later does it sink in how intuitively to the point her performance has been.

These days, she usually plays bubbly all-American girls, but the buried whammy of her roles' innocuousness is that she spent her screen childhood incarnating perversity. Before she hit puberty, she kept getting cast as an unsettling, often precociously sexualized presence: the spooky twelve-year-old heroine of Interview with the Vampire , the Nazi police chief's daughter in the adaptation of Kurt Vonnegut's Mother Night , Randy Weaver's gun-toting progeny in the remarkable 1996 TV docudrama Ruby Ridge: An American Tragedy . That's also how she was used in The Virgin Suicides , at which time she was (barely) old enough for her allure to get copped to openly, though not much less unnervingly.

Dunst has a knack for making her characters' thought processes so understandable that it's impossible to stay out of sympathy with their motives. Even in her frothiest movies, she doesn't play airheads; she plays young women who don't know they've got brains. She does it again in The Cat's Meow , the first big-screen feature in nearly a decade from Peter Bogdanovich--not that many people have been holding their breath. It's also the first time Dunst has been cast as an adult, assuming that William Randolph Hearst's mistress Marion Davies qualifies.

Adapted from a Steven Peros play about one of early Hollywood's murkier scandals--a celebrity-studded 1924 cruise on Hearst's yacht that ended in the death, probably by foul play, of once-legendary producer Thomas Ince-- The Cat's Meow is basically highfalutin gossip, one of those determinedly offbeat projects that look vaguely classy without being all that distinguished. The script's intermittent cleverness too often settles for the Lion in Winter ploy of recycling tired, bitchy quips by putting them in the mouths of the great, and ultimately there's not much to say for a movie that treats dancing the Charleston as a meaningful symbol of twenties frivolity.

Dunst, though, is terrific in it. Given Bogdanovich's history of involvement with youthful actresses, it's slightly creepy for him to cast a nineteen-year-old as the mistress of a powerful man more than thirty years her senior, and it would be even if, in his jealous outbursts, Edward Herrmann didn't look uncannily like a distraught Bogdanovich. Yet not only does Dunst play Davies without quotation marks--as if she were a real human being, not a cartoon--but you never catch her trying to measure up in a cast that, besides Herrmann, includes Cary Elwes doing none too well by Ince, AbFab's Joanna Lumley as Elinor Glyn (who else?), Jennifer Tilly, the world's most complacent banshee, doing her patented yowl as Louella Parsons, and British comic Eddie Izzard as Charlie Chaplin. In Peros's gimmicky speculation on events, a dalliance between Davies and Chaplin goads Hearst into the jealous rage that leads him to bump off Ince by mistake.

In what turns out to be Dunst's big scene, Chaplin does most of the talking. He's just gotten Davies to sleep with him at last, and now he's begging her to leave Hearst and become his leading lady. Unfortunately, Izzard, whose performance is expert when he's just sidling into scenes to deliver cutting remarks--he's Chaplin confused with Oscar Wilde--flounders when he's got to provide dramatic sparks. Yet you barely notice his frantic spiel; you're mesmerized by Dunst's reactions. She's playing a likable, carefree woman who prides herself on not being calculating. But now she's thinking fast, and you watch her figure out that taking a chance on love is one thing but swapping a megalomaniac who dotes on her for an unreliable narcissist is another. As she does, her character's unrefiective face grows so eloquent that Davies's decision goes on making sense even after the murderous denouement.

Most likely, not many people will see The Cat's Meow , and aside from Dunst's performance, they won't be missing much. She's sure to get more attention as Peter Parker's love interest, opposite that contented imp Tobey Maguire, in next spring's Spider-Man . Since the original material is both droller and more humane than, oh, Batman, the movie may not even be bad. It's still insufferable that at the stage of Dunst's career when you want her to graduate to grown-up parts as rich and fresh as her juvenile ones, playing Spider-Man's girlfriend is shaping up as her breakthrough role.

PREDICTABLY, Dunst's gifted contemporaries are facing similar binds. Since Hollywood's ongoing youth craze strikes most critics as insipid by definition, even Meg Ryan gets taken more seriously than today's astonishing crop of terrific young actresses--not just Dunst but Reese Witherspoon, Christina Ricci, Thora Birch, Natasha Lyonne, and so on, all of whom are miles livelier and more idiosyncratic than Ryan or Julia Roberts. These days, it's the male ingenues who are vapidly pretty; next to Josh Hartnett, the Hedy Lamarr of high school jocks, even Mena Suvari looks ready for Ibsen. Conventional wisdom to the contrary, it's not quite true that today's movies don't feature good roles for actresses. It's just that nearly all the ones that let them show their mettle are written for women who aren't old enough to vote. When was the last time an adult actress got to be as sassy and indifferent as Ricci was in The Opposite of Sex or as matter-of-factly observant about her plight as Lyonne in Slums of Beverly Hills ? Birch's uncompromising Enid is the heroine of Ghost World , but if you left it to Hollywood to turn Enid into a grown-up, she'd end up as a Janeane Garofalo part--a sidekick.

Since Dunst, unlike Lyonne or Ricci, does have the kind of cheerleader prettiness that fits the industry's notions of beauty, she's almost sure to fare better. But how much better? In commercial terms, Witherspoon is the one who broke out this year, but Legally Blonde , however enjoyable, is such basically inept fiuff that it wouldn't exist without her performance--abetted by a director who's understandably happy to photograph her looking gorgeous until the cows come home. She's marvelous, but her acting here isn't a patch on her tougher work in Pleasantville or Election .

It's also unclear just what the A list gives Witherspoon to look forward to, unless she wants to settle--a term I use advisedly--for being the next Julia. Right, she's a cutie, but she's also more than that, even in looks; with that determined chin and take-no-prisoners forehead, she could play the title role in U-571 . Like Witherspoon's, Dunst's attractiveness is never bland; there's too much going on in her face. Men can't respond to her looks without being aware of the consciousness behind them, and Hollywood's (or men's) unease with that implicitly challenging kind of appeal is why Tuesday Weld never became a big star.

One reason it seems appropriate for Dunst to play a silent star in The Cat's Meow is that she's got a seemingly unaffected gift for making unarticulated emotions photographable. For her generation of actresses, though, adulthood is looming as a transition almost as perilous as the coming of sound. In fact, what's most revealing about The Cat's Meow is that Dunst had to go to an eccentric Canadian-German coproduction to find a role that tests her--in a movie that isn't even all that good.

It's going to be our loss if Hollywood doesn't come up with better parts for her--and for her contemporaries, too. The vitality and emotional honesty that they've been able to show in their juvenile roles only underline the short shrift today's movies give grown-up women, and I'm hoping that they're good enough to force the biz to adapt to them as they mature instead of the other way around. Dunst has already done extraordinary things, but won't it be a shame if we have to look back on her teen comedies and say, "That was her peak"?