Most of us have a delay button that lets us weigh what we think before we say it out loud. That’s not the case for Taylor Bradley Scott, the acid-tongued entomologist in Lydia Diamond’s play “Stick Fly.” Thoughts fly out of her mouth at breakneck speed, setting up a scene with tension that’s as thick as brie.

In Marion McClinton’s laudable production of Diamond’s family drama, which had its regional premiere Friday at Park Square Theatre, actor Traci Allen nails the role with fiery intensity. She expands on the skills she’s displayed at the Children’s Theatre, where her roles have included the wide-eyed innocent title character in “Lizzie Bright and the Buckminster Boy.”

Allen is not the only one doing praiseworthy work in a cast headlined by stately veteran James A. Williams and lyrical Tracey Maloney.

If Diamond’s play breaks new ground, it is in offering a window into a precinct of the upper-crust black intelligentsia rarely seen onstage or on screen. The play is set at a family retreat on Martha’s Vineyard where Taylor, a bug lover with daddy issues, has gone with her boyfriend, Kent (Darrien E. Burks), to meet the rest of his clan.

Kent, whom she calls Spoon, is an aspiring writer, a vocation which his father (Williams) and older brother, Flip (Darius Dotch) — both doctors — view with disdain. Flip has brought his white girlfriend, Kimber (Maloney), home for introductions as well. But by the end, the family’s many secrets leave the characters reeling.

Playwright Diamond is aptly named. Her well-structured play offers many facets of light and levity, and her dialogue often crackles. The one annoying affectation is that she sometimes has two scenes going simultaneously with multiple characters speaking the same lines — a device that is common in musical theater, where it usually involves some sort of love triangle. Here, it just feels cutesy and does not add meaning or deepen the emotions.

It doesn’t help that Michael Kittel’s lighting design fails to delineate the locales of the action — inside and out, living room and kitchen — sharply enough.

These shortcomings are redeemed by the excellent cast, all of whom hit their marks with aplomb. As the patriarch with a secret yen for pickled pig’s feet, Williams says as much with grave silence. He delivers with a commanding meanness.

Burks’ role could be a whiny one; Kent is searching for his authorial voice even as he faces family discouragement. But the actor makes this character sympathetic. As his older brother, Dotch brings literal muscularity to the role of a plastic surgeon/ladies man.

Maloney invests Kimber with tenacity and wryness. And young actor Brittany Bradford, who depicts a pivotal character, is a pleasure to watch.

The Broadway staging of “Stick Fly,” which was backed by singer Alicia Keys, was knocked for being too much like a sitcom. There should be no such complaints about McClinton’s staging, which couples humor with depth and gravitas.