“The Kids Are All Right” is a decent, if flawed, examination of the difficulties of family life, adolescence, marriage and everything else in between.

The film revolves around a modern family on the cusp of an emotionally difficult transition period—one in which their eldest child will depart for college. It’s a precarious situation made all the more complicated by the arrival of an unexpected intruder.

That intruder is Paul, played to perfection by Mark Ruffalo. Paul is a mellow, organic food restaurateur who, 19 years ago, served as the anonymous sperm donor to the parents of the family—lesbian couple Jules and Nicole— played by Julianne Moore and Annette Bening, respectively. Their 18-year-old daughter, Joni, played by Mia Wasikowska, is enjoying her last summer at home when she contacts Paul at the behest of her brother Laser, played by Josh Hutcherson. Much drama ensues—awkwardly humorous, emotionally distressing, and realistically touching.

Although Joni and Laser are the ones who decide to seek out their biological father, neither their personal desires nor motivation behind this act is satisfactorily explored. Like the song by The Who that it is named after, “The Kids Are All Right” is focused primarily on the plight of the adults—specifically, the parents and the man that suddenly becomes a part of their lives.

Co-screenwriter and director Lisa Cholodenko has examined the effects that an outsider can have on a relatively stable couple in previous works such as “High Art” and “Laurel Canyon” as well—but here she does so at the expense of her supporting players.

Bening, Moore and Ruffalo are all excellent in their roles—the Type-A mom, the easy-going parent, and the accomplished slacker, respectively—and the characters don’t feel like one-dimensional stereotypes. Wasikowska and Hutcherson do a nice job with the material they are given, lacking as it might be. The first two-thirds of the film is refreshingly low-key in its approach as it generally favors awkward silences and exchanges instead of having the characters bluntly voice their thoughts and feelings in a less-believable manner.

Events take a turn for the contrived when a sporadic affair blooms between Jules and Paul. This turning point in the narrative does not arise naturally—it feels forced, as though screenwriters Cholodenko and Stuart Blumberg merely wanted to raise the stakes for the sake of introducing even more drama into the film’s proceedings.

“The Kids Are All Right” is an up-close-and-personal film in terms of its aesthetic and thematic design. It conveys the unspoken conflicts and feelings of its various characters well enough before it introduces a more melodramatic element such as infidelity into the plot.

Things do eventually build to a satisfying climax, as well as a conclusion that refrains from wrapping up every plot thread in a neat and tidy fashion. For better or for worse, some issues are resolved relatively easily—certain characters move on with their lives or show signs of making progress and others are left more in a stasis, their future unsettled.

“The Kids Are All Right” is a lot like the family it revolves around—imperfect, prone to making significant mistakes, but realistic enough in form and function that moviegoers will be able to admire its overall quality while still acknowledging its shortcomings.