WITH SAVAGE WIT, HE KICKS AND SCREAMS TOWARD ADULTHOOD.

Byline: Bob Strauss Film Critic

`ABOUT A BOY'' is one of those happy movie occasions in which all involved rise to the quality of the material.

The source is Nick Hornby's 1998 novel, a sentimental yet slyly honed study of a confirmed English bachelor's belated coming of age. Like Hornby's previous book ``High Fidelity,'' ``About a Boy'' bristles with sharp insights into how modern pop culture arrests emotional development. But more than ``Fidelity,'' which was also turned into a pretty decent movie, ``Boy'' makes a stronger case for that not being such a bad thing, especially when contrasted with the substantial negatives serious relationships with flawed fellow humans entail.

Of course, popularity demands that the need for other people gets due respect in a story like this. But the tension between that inevitability and celebratory selfishness makes for delicious screen comedy here. And directors Paul and Chris Weitz - yes, the same brothers who were responsible for ``American Pie'' - sustain that balance well, avoiding countless opportunities to go for sappy sweetness when egocentric attitude and tartly turned lines can be applied.

All of which gives Hugh Grant his best role ever. Will, the film's 38- year-old protagonist, echoes both the facile comic charm that has long been the British actor's trademark and the heartless caddishness that's come out so nicely in more recent films such as ``Bridget Jones's Diary'' and ``Small Time Crooks.'' But Will is very different, more fully elaborated, than the dithering romantics and untrustworthy snakes of Grant's past work. For a self-described (and mighty proud of it) Shallow Hal, Will turns out to be amazingly deep in contradictions, insights and, eventually, feelings.

Maybe that's because he hasn't been distracted by the responsibilities that most adults spend their energies on: spouse, kids, job. Blessed/cursed with a bizarre legacy - his one-hit wonder dad wrote a stupid Christmas jingle whose perennial appeal has kept Will rolling in royalty dough since puberty - our lad spends his life contentedly watching TV game shows, purchasing the trendiest clothes and CDs, having his hair professionally mussed and, of course, pursuing the most zipless romances he can find.

An unusually rewarding (because it is pleasantly undemanding) liaison with a single mother opens Will's eyes to a whole new field of endeavor: short flings with grateful-for-any-attention mums without mates. How to meet more, though?

Pretending to be the wife-abandoned father of an imaginary 2-year-old, Will attends an otherwise all-female single-parent support group. What this despicable ploy actually gets him, however, is a real boy.

Twelve-year-old Marcus (newcomer Nicholas Hoult, who adroitly treads a fine path between obnoxious and pathetic to something resembling likably genuine) is bullied at school and saddled with a depressive, sometimes suicidal, post-hippie mother, Fiona (Toni Collette, perfectly cast) at home. Desperate for any island of escape as well as a father figure, Marcus is the first to figure out Will's deception, then blackmails him into being a buddy.

As we know he must, Will slowly learns to care for the kid, and therefore becomes vulnerable for the first time in his life. He even falls in actual love with another parent-on-her-own, Rachel (``Mummy'' movie stalwart Rachel Weisz). But his old deceptive, commitment-dodging habits die hard.

And thank heaven for that. Had Will become a softy any sooner than he does, the movie would have died right then, along with anything interesting about Grant's performance. But even though ``About a Boy'' traffics in some of the same contrivances that many British romantic comedies employ, it maintains a harsher, more honest skepticism of human nature than most. And a meaner sense of humor, too. Both Will and Marcus possess perceptive inner voices that are repeatedly heard on the soundtrack. It's a ploy that usually doesn't work, but is so well-written and dryly delivered in this case that it lends the movie a whole extra dimension of meaning.

A long way from ``American Pie,'' this. Yet the American Weitzes prove to have been inspired choices for this specifically British yet very universal comedy. As the teen gross-out comedy indicated, they know why men don't want to grow up, why they ought to, and how to make them do it - and how they even may learn to love it.

ABOUT A BOY - Three and one half stars

(Rated PG-13: language)

Starring: Hugh Grant, Nicholas Hoult, Toni Collette, Rachel Weisz.

Director: Paul and Chris Weitz.

Running time: 1 hr. 41 min.

Playing: Wide release.