Alan Rickman in Bottle Shock Credit: Bottle Shock

Alan Rickman in Bottle Shock Credit: Bottle Shock

So when is a doc not a doc? Moviegoers have pondered that one ever since Robert Flaherty bent the parameters of nonfiction by supposedly staging scenes in 1922's Nanook of the North, one of the first and most famous feature-length documentaries (or docs, as we syllable-phobics prefer to call them).

Flaherty shouldn't take the whole rap for the increasingly slippery notion of truth that's been percolating since Nanook, but audiences nowadays certainly do have a more complicated, love-hate affair with our docs. On one hand we modern types crave "reality programming" of all sorts, on screens both big and small, from The Real World to Dogme-esque productions that meticulously ape reality, but aren't. On the other hand, we cling to irrational fears of the dreaded "D word," leery of anything that might, horror of horrors, attempt to teach us something without a sufficient sugarcoating of entertainment.

Nanette Burstein's American Teen, ostensibly a documentary, goes down so smooth that a prime-time broadcast on MTV wouldn't be at all out of the question. (Not that there's anything wrong with that.) For what it's worth, the audience at the American Teen screening I attended included several sizable packs of adolescent girls who entered the theater giggling as if they were about to see American Pie, and walked out even giddier. Now there's some writing on the wall for you.

Burstein (who also directed 1999's The Kid Stays in the Picture) takes her camera into a typical high school in a typical town — the mostly white, mostly middle-class community of Warsaw, Ind. — where she focuses on a group of seniors during a transitional time in their lives. The kids seem to fit into easily recognizable molds and readily identify themselves as such — at least at first, as we meet Colin the Jock, Jake the Nerd, Hannah the Rebel and Megan the Popular One (who leads a clique of hotties straight out of Heathers or Mean Girls). As we watch their lives unfold, however, the lines blur as identities are questioned, new alliances are formed (and fractured) and the kids deal with the various pitfalls of growing up, rising and falling and sometimes rising again.

It's often surprisingly gripping stuff, but nagging questions remain that maybe it's all a little too gripping. It's not inconceivable that Burstein was able to so completely gain the confidence of her subjects that they willingly allowed themselves to be filmed in the compromising and even incriminating positions sometimes seen here — but it's considerably harder to believe that the filmmaker was able to be in exactly the right spot at exactly the right moment to catch some of the film's supposedly spontaneous emotional explosions.

Engaging as they are, these moments don't always ring completely true. At worst, they feel a bit like dramatic re-creations, almost as if the kids were milking the moment for the camera or even working off some loose outline of a script. Then again, perhaps this is just the natural byproduct of what happens when you attempt to document members of a generation raised on Survivor, for whom the lines between reality and reality programming no longer matter. When everybody's already walking around in their own little 24/7 movie, whether they know it or not, new ideas develop as to what it means to be "natural."

The authenticity conundrum isn't helped by the movie's overall slickness — teen-friendly tunes constantly bubble underneath the action, and glossy animated fantasy sequences periodically materialize to illustrate the characters' predicaments. Credibility issues aside, though, it's almost insidious how easy it is to be seduced by the film as it roots around in the sometimes cruel but usually fascinating social dynamics of young adults trapped in a too-small space, turning on each other and themselves out of neurotic need or boredom. Whether what American Teen shows us is strictly true or not is another matter, but, as we're constantly learning, the truth can be as fluid as we need it to be.

Another twist on the documentary phenomenon is the movie that begins by telling us it's "based on a true story." This week's entry is Bottle Shock, one of the better ones. Bottle Shock doesn't play as fast and loose with facts as some, but it doesn't hesitate to throw in a made-up romance or two and some trusty father-son tensions to embellish its essentially accurate account of the landmark event that finally gave American wines the respect they deserved.

That event — a blind tasting held in Paris during American's bicentennial year, and judged by France's most esteemed oenophiles — resulted in a couple of rag-tag California wineries shocking the world by, for the first time ever, stomping all over their French counterparts.

The movie spends a little too much time watching everyone chase their tails. Bottle Shock is at its best when it doesn't try to be Sideways (that movie was ultimately about the complexities of people; this one's really a story about wine). But the film's characters are an appealing if somewhat broadly drawn bunch, and the tone manages to be uplifting in a non-preachy, non-pandering way as it plugs along toward that Yankee-Gallic showdown we're all waiting for. Bill Pullman and Chris Pine are solid as the head-butting father-and-son proprietors of a struggling Napa Valley winery, and Alan Rickman is a lot of fun as the British wine snob who discovers the joys of California while putting the tasting event in motion.

Like Sideways, Bottle Shock gets a lot of mileage from using humans and wine as interchangeable metaphors for each other (adversity makes them both stronger, both produce ugly ducklings that become swans), and it all takes place in a weirdly magical California where even the most rough-and-tumble bikers know the difference between a Merlot and a Zinfandel.

The film splits its time between Paris and the rolling hills of Napa, the music an appropriate mix of Maria Callas and the Doobie Brothers, with scenery so voluptuous and sun-drenched you have to restrain yourself from sticking your face in the screen to lap it all up. And that's the truth.