Your jaw cannot help but drop when the curtain at Mixed Blood Theatre opens on “Hir,” Taylor Mac’s absurd and often absorbing deconstruction of the prototypical white American family.

Designer Joseph Stanley’s sitcom-like set — a cutaway of a dreary, ’80s-vintage living room and kitchen — looks like it has been through a tornado. Laundry and trash clutter every surface and the mess is occupied by two nonchalant people who don’t seem to care.

Paige (Sally Wingert), a mother and wife, is sentient and clearly together but is gleefully on strike against domestic expectations. In fact, she throws her discards onto the mess. Her husband, Arnold (John Paul Gamoke), has fewer wits about him. A stroke has rendered him a doddering shadow of a man who now walks around in a sheer nightgown and diaper. Paige plays dress-up with him, putting him in clown costumes as she barks orders and questions at him. He mutters one-word answers.

Viscerally staged by Niegel Smith, “Hir” is a play that is both a lacerating “American Family”-style sitcom and a potent domestic drama that ends with devastating poignancy. It offers an unexpected whorl of ideas and themes that takes a viewer to surprising places, even as it becomes somewhat repetitive.

“Hir” also is an educational and instructive exercise for playwright Mac, who has cleverly written a piece that brackets a viewer’s conventional expectations. To ask him for dramaturgical consistency, like, say, to have “Hir” be done either as comedy or drama, is to cross one of the themes in the play.

“Hir” is about broadening our ideas and conception of gender. The two other characters who populate this world are Paige and Arnie’s children. Son Isaac (Dustin Bronson), a militaristic, order-imposing figure, has been discharged from the armed forces after serving in Afghanistan. When he comes home, his sister, Maxine (Jay Eisenberg), has become his brother Max, who instructs him on the proper pronouns to use (“hir” and “ze”).

In his muscular production, director Smith gets very affecting performances from every member of his acting quartet. Gamoke invests Arnie with clownlike innocence. You want to root for him as he gets beaten up and even as the shadow of his own history lurks. Wingert gives Paige the zeal of a new convert, except her religion is all about self-liberation. The actor rattles off long lines of dialogue with characteristic aplomb, dropping the term “hetero-normative” with ease, the way some talk about recipes and apple pies.

Bronson’s Isaac is a restless figure, and the actor, in his tics and swerving, let’s us see into the character’s distemper. Eisenberg’s Max is perhaps the most sympathetic character, as it should be, since Max has the most dramatic arc.

If “Hir” has a challenge, it is that playwright Mac’s educational impulse sometimes overwhelms his dramatic sensibilities. As the script repeats ideas and themes to make sure that we get them, it underestimates our intelligence. Still, that impulse is understandable, given that this 105-minute play, written a year ago, is so thematically and stylistically up-to-the-minute.