Engrained in the mind of every American kid is the myth of the life-changing summer—those three languid months between the end of childhood and the first steps into real life, a series of long days without parents or school to live wildly, fall in love, and find one’s true self. June, July, August: enough time to take a walk on the wild side, turn around, and walk back.

In “The Mysteries of Pittsburgh,” written and directed by Rawson Marshall Thurber (“Dodgeball: A True Underdog Story”) and loosely based on Michael Chabon’s debut 1988 novel of the same name, this mythic summer is distilled into 80 minutes of saccharine images and angsty declamations. Coming of age in Thurber’s colorful, melodramatic Pittsburgh is more of an unattainable ideal than an actual transformation of moral fiber. While they do their best to push the boundaries of their young existence, Thurber’s formulaic characters don’t have much to grow out of.

Art Bechstein (Jon Foster) comes to his fabled summer a little late. Fresh-faced, clean-shaven, and forever dressed somewhere along the spectrum of white shirt/jeans to blue shirt/chinos, Art is a recently graduated economics major planning to work in finance in the fall. He needs adventure, and soon—lest his life become as boring as he has set it up to be. Judging from his blank stare throughout the movie, he’s already beginning to fall into his own trap (I suspect that he’s introspecting but have little proof). “If this was to be the last summer of my life, I wanted to have the least amount of responsibility possible,” Art says in a voiceover suitably devoid of emotion. Not very convincing.

Adventure arrives in the form of Jane (Sienna Miller) and Cleveland (Peter Sarsgaard), a couple so alluring that Art cannot help but follow them as a third wheel. Jane plays the violin brilliantly but loves punk; she’s the kind of girl who softly asks, “Do you like pie?” in an accent caught somewhere between Tennessee and the acting studio. Cleveland, her boyfriend, is the most American of young heroes—a rebel without a cause, a lost genius falling into the unstoppable maelstrom of his own reckless energy. Together Jane and Cleveland make for a sort of Abercrombie and Fitch representation of youth, their skin literally glowing under the soft gaze of cinematographer Michael Barrett’s lens.

Their time together is predictable. After shifts at the Book Barn, where Art alternates between shelving books and sleeping with his conventionally unconventional supervisor, Phlox (Mena Suvari), he and the couple go on all sorts of romps. Skinny-dipping, soccer with young children, crazy nights out on the town—Thurber presses the “summer” button again and again. Hours pass lounging at the abandoned “Cloud Factory,” Thurber’s lone and treacly nod to Pittsburgh’s industrial past.

But it’s not all fun with Cleve and Jane. As an antidote to the plot’s syrupiness, Thurber plops in a very vinegary element: the mob.

References to the Pittsburgh gang scene run throughout the movie, just detailed enough to flash “real life danger” on the screen. In fact, while Thurber keeps the mob at a considerable distance (we don’t know, for example, why Cleveland is involved), he relies on its existence to compensate for the poorly developed elements of the flaccid plot. If Art is vapid, it is because he lives in the shadow of a gangster; a scene with a pistol juxtaposes cheerful bonding in the hope that cliché plus cliché might make some real life.

Acting does not add complexity to the situation. Granted, the actors are not given much (one of Jane’s key moments repeats the word “what” eight times in about 20 seconds), but they do little to expand on the heavy-handed screenplay. Each seems to latch onto a particular physical characteristic—Art’s slightly furrowed eyebrows, Jane’s girl-next-door smile, Cleveland’s carefree gaze—as if it were the only way to access a real character.

Rather than an impression of a summer, “The Mysteries of Pittsburgh” is like an impression of a summer movie. All the elements are there—love, self-exploration, and encounters with danger—and each is devoid of any interiority. To put it plainly: there’s no mystery.

—Staff writer Madeleine M. Schwartz can be reached at mschwart@fas.harvard.edu.