But they are not the play’s problem; the biggest threat they pose to the status quo is their superannuated roughhousing. In their early 40s, they still give each other wedgies.

Rather, it’s the oldest brother, Matt (Paul Schneider), who precipitates a crisis. Burdened by decades of student debt — and by an unexplained failure to thrive that has left him a self-described loser — he has returned home to live with Ed (Stephen Payne). He cleans and cooks, and would fully earn the unpaid domestic labor bonus if it really existed.

Though Matt says he’s happy with his choice, his upscale brothers, noting his horrible clothes, worry that he’s depressed. (The dead-on costumes are by Suttirat Larlarb.) His temp job making copies at a local community organization reads to them as a form of self-flagellation, so far beneath his abilities as to suggest pathology or, even worse, politics. Jake thinks Matt has deliberately suppressed any ambition to make room for others who have traditionally been excluded from positions of authority. Drew thinks he needs therapy.

Instead of resolving the mystery of Matt, Ms. Lee astutely complicates it. In boyhood, he was the most rigorously committed of the three to social justice, even forming a school for young revolutionaries whose fight “song” was an excerpt from Hegel. But as the wrangling over Matt becomes the main action of the play’s second half, the tonal shift from naked comedy to psychological witch hunt — it’s almost like a “Crucible” for underachievement — starts to seem heavy-handed.