Idris Brewster, left, and Seun Summers, from middle-class black families, faced a unique opportunity at the elite Dalton School in New York in “American Promise.” (Michele Stehenson)

For 13 years, Joe Brewster and Michele Stephenson shot video of their son, Idris, and his friend, Seun. Both kids lived in Brooklyn, the products of middle-class black families, and they found themselves with a unique opportunity. As kindergartners, both were accepted into the Dalton School, an Ivy League farm team on the Upper East Side whose alumni include Wallace Shawn, Claire Danes, Anderson Cooper and many other notables.

American Promise” is the result of the hundreds of hours of footage. The documentary is unwieldy, unfocused and frustrating at times, no doubt in part to the relative inexperience of its parents-turned-filmmakers and their nebulous motives for turning their camera on in the first place. But the movie is also, somehow, dazzling. The fact that the pair pulls off the nearly 21 / 2-hour run time without making the audience tire of the subjects is a feat itself. Thankfully for both directors and audience, Idris and Seun turn out to be adorable little boys who become impressive young men. More importantly — and perhaps unintentionally — filmmakers Joe and Michele make for fascinating subjects, as well.

Dalton seems like a good fit for the boys initially. The two love school and their classmates, although there are inklings of outsider feelings. When Seun tries to brush his gums until they turn pink, so he can be like the other kids, it’s a harbinger of challenges to come. As years go by, the children begin to feel they belong neither at Dalton nor in their neighborhood, where other kids tell Idris he talks “like a white boy.”

To make matters worse, both are having a hard time academically. Or are they? That’s just one of the nagging questions the film offers up, then leaves unanswered. At one point, Michele and Joe take exception to the fact that Seun and Idris are singled out for private tutoring. Seun, who is diagnosed with dyslexia during the film, could use the extra help, but Idris’s parents seem to think their son is being unfairly targeted. Joe marvels at how Dalton seems to think their son is a challenging pupil. “They don’t know him,” the father states matter-of-factly. And yet, Joe and Michele are exceptionally harsh helicopter parents, whose demeanor suggests they think their son is indeed difficult. (From an outsider’s perspective, Idris seems both precocious and highly emotionally intelligent.)

These bits of hypocrisy turn the movie into an engrossing portrait of modern parenting. The filmmakers offer few insights into why the kids struggle at Dalton or why Dalton struggles with them. But they do give some vivid examples of how being an overbearing guardian can backfire. “I was so independent at that age,” Michele laments at one point. “I just wish he had half the drive I had.”

To their credit, the filmmakers lay bare their foibles, as well as their bickering over parenting techniques. And while the access they get is impressive — there’s plenty of footage inside classrooms — the little domestic moments and private conversations mean so much more. “American Promise” may not fully document or explain how race affects education, but it does offer plenty to ponder.

★ ★ ★

Unrated. At Landmark’s E Street Cinema. Contains nothing objectionable. 140 minutes.