Whither the Wilson brothers? It's 11 years now since the three strapping Dallas lads—Andrew, Owen, and Luke, going from oldest to youngest—first appeared in Bottle Rocket, Wes Anderson's debut feature about a gang of bumbling thieves. Since then, the younger two have arrived at the graced state of movie stardom without appearing to break a sweat. In fact, not breaking a sweat is integral to the Wilson ethos. You won't see these guys losing 60 pounds for a role, Christian Bale-style, or jawing about their craft to James Lipton on Inside the Actors Studio. They amble from movie to movie with the insouciance of the Southern slackers they are, always giving the impression of being busy elsewhere with something more interesting.

The quintessential Wilsonian protagonist is a gifted but aimless young man, a bit too slick for his own good, who disappoints everyone by failing to live up to his promise—then, in the last act, he puts in just a little more effort and manages to get the girl and win the day after all. But (to paraphrase a recurring line uttered both by and to Owen's ne'er-do-well character in Wedding Crashers), the Wilsons aren't that young. Luke is 35 now, Owen 38, and Andrew—the seldom-seen Gummo of the Wilson clan and co-director of their just-released venture The Wendell Baker Story—has crossed the four-decade Rubicon to 42. The Wendell Baker Story is too slight a goof to withstand much critical scrutiny—let's just say that it disappoints, Wilsonishly, by failing to live up to its promise. But that very fact makes the movie as good an excuse as any to assess the brothers at midcareer.

Owen has carved out two separate niches for himself: as co-writer of the clever if increasingly hollow Wes Anderson films in which he also appears (Rushmore, The Royal Tenenbaums), and more prominently as the Butterscotch Stallion, the eternally bemused golden boy in heist capers (The Big Bounce), buddy spoofs (Starsky & Hutch; Shanghai Noon), and romantic comedies (Wedding Crashers). Owen at his best, adrip in sun-kissed smarm and immune to negativity, is exemplified by the character of Kevin, Teri Polo's aggravatingly perfect ex-boyfriend in Meet the Parents. Kevin is everyone's nightmare rival, a master at skydiving, horseback riding, and carpentry (because "if you're going to follow in somebody's footsteps, who better than Christ?") and the funniest onscreen rival since Tim Robbins' sanctimonious karate expert in High Fidelity. In this scene, Kevin unveils his wedding gift, a hand-carved wooden altar, with a finely calibrated mix of modesty and self-congratulation that bespeaks the essence of Wilsonness.

The bad Owen lies just a hair's breadth away from the good one. Strip Kevin of his subtlety, dumb down his dialogue by 15 percent, and that hail-fellow-well-met bonhomie begins to shade into frat-boy complacency. This is what's happened in Owen's last few romantic comedies, most notably the dreary You, Me and Dupree, which repackaged Owen's loopy appeal, his legitimate weirdness, into the stock humor of the "wild and crazy guy." Owen plays Dupree, the cutup college buddy of the straitlaced Matt Dillon (who should have won a Purple Heart for all the mugging he stoically endured). Here, Dupree settles in as the unwelcome houseguest of Dillon and his new bride (Kate Hudson), toting a ukelele and a taxidermied moose head.

Notice how Dillon checks his watch as Dupree begins to ramble about being fired from his job. Is the old Dupree (read: Wilson) charm beginning to wear thin? Are the practicalities of adult life rearing their ugly heads? Dupree (and, to a lesser degree, Wedding Crashers) takes as its theme these questions without seeming to realize that its leading man also embodies them. Dupree's cuteness, the movie wants us to believe, is on the wane—and he has about 90 minutes to learn his lesson and grow up. This being a romantic comedy, he gets the job done in time. But in order for this conceit to work, the audience has to accept Owen Wilson's cuteness as a given; unlike Matt Dillon, we're not supposed to be consulting our watches in the dim theater light. With his crooked nose and wheedling drawl, Owen is a winning enough presence to survive the movie relatively unscathed. You walk out still liking him, but resentfully, as if you'd let your own college buddy sweet-talk you once too often.

As for Luke, he's most often cast in the Joel McCrea role: the humble and diffident nice guy, oblivious to his own handsomeness and just smart enough to realize that he's not quite sure what's going on. The difference is that McCrea pulled off those beleaguered-Average Joe roles with style and wit, whereas Luke, especially when playing a straight romantic lead, can be as limp and tepid as a wet sock. In this scene from last year's unfortunate My Super Ex-Girlfriend, his discomfort is painfully visible as he finally professes his feelings to Anna Faris. As Faris hurls herself into his arms, Luke appears to be thinking about something else entirely: His briefs chafe, maybe, or he left his wallet on the craft table. Granted, it wasn't Wilson (or his brother) who wrote this lumpen dialogue. But he still agreed to speak it, and after a certain point in an actor's career, that choice means something.

Having seen an example of the bad Luke—sincere but floppy, like a lovestruck Labrador—let's take a look at the good one. In Idiocracy, Mike Judge's bleakly dystopic vision of America's stupid future, Luke's "who, me?" persona is perfect for his role as the hero by default, an Army scrub who's cryogenically frozen and wakes up centuries hence as the smartest man alive. Here, he takes the mic at a public gladiatorial event to suggest, ever so politely, that America try irrigating its crops with water instead of a bright-green sports drink called Brawndo. The gladiator who makes the "what a fag" gesture at the end of Luke's speech is the aforementioned Andrew, who's become such a regular in these jokey cameos in his brothers' films—he's Future Man in Bottle Rocket, the coach in Rushmore, a cop in Charlie's Angels: Full Throttle—that Andrew-spotting should become its own drinking game.

In The Wendell Baker Story, Luke plays the classic Owen role: He's a good-hearted small-time swindler who takes a job at a nursing home upon his release from prison. Owen is cast against type as the villain, a coldhearted nurse who's scamming the residents out of their government checks by faking their deaths. With the help of two horny codgers (Seymour Cassel and Harry Dean Stanton, both terrific), Luke's Wendell saves the home and wins back his girl (Eva Mendes, as handsome and stiff as a carved figure on a ship's prow) from her new grocer boyfriend (Will Ferrell, uncredited and hilarious).

The Wendell Baker Story is fine for what it is, a shaggy caper comedy with a vaguely 1970s vibe (though it's set in the present day) and an amiable country-rock soundtrack. But it doesn't feel like something worth waiting two years for (that's how long the film sat on a shelf before landing a distribution deal). The Wilsons got a sweet deal from the gods at birth: good looks, brains, and a sense of humor. But they've coasted far enough on those gifts. As they round the corner into the prime of their lives—it isn't autumn yet, but it's certainly July—I feel sort of like their fond but exasperated middle-school teacher. I'm waiting for them to push themselves … and I'm beginning to drum my fingers on the table.