The subject of the black family and its relationship to racial progress in America has never been neutral. Historians, social scientists and armchair critics from all quarters have led fractious debates defending or condemning it. These polemics all too often overshadow the very human experience they purport to understand, reducing to caricature full and entangled lives.

In her luminous and remarkably assured first novel, “A Kind of Freedom,” Margaret Wilkerson Sexton cuts through this haze to shine an unflinching but compassionate light on three generations of a black family in New Orleans who try to make the best choices they can in a world defined at every turn by constraint, peril and disappointment — a world in which, as one of her characters puts it, you quickly “learned the hard way that life could drag disgrace out of you.”

For a debut novelist to take up such charged material is daring; to succeed in lending free-standing life to her characters without yielding an inch to sentimentality — or its ugly twin, pathology — announces her as a writer of uncommon nerve and talent.

In “A Kind of Freedom,” Sexton pursues a family’s history in a downward spiral, with three alternating plot lines that echo one another along the way. The novel opens in 1944, with the budding love of Evelyn, a daughter of a well-to-do family (her mother is Creole, her father a black doctor who has raised himself to respectability), and Renard, a young man from a poor Twelfth Ward neighborhood who works menial jobs at a restaurant but aspires to study medicine. Their courtship, though ardent, reveals the strictures of a class- and color-riven society that suffocates ambition and distorts desire.

Forty years later, Evelyn’s daughter Jackie is a struggling single mother in 1980s New Orleans who is in love with her child’s father but afraid he will succumb to his crack addiction. Eventually, we get to know Jackie’s son, T.C., in 2010, a young man at a turning point in his life. Through T.C.’s eyes, Sexton portrays a post-Katrina New Orleans where the smell of mold still lingers and opportunities for fast cash in the streets abound, as do the chances of getting shot or arrested.

Sexton is a native of the Crescent City, and one of the pleasures of this novel is its feel for the particulars of local language, texture and taste: a jar of pickled pig lips, a family crawfish boil, the turn of an old Creole phrase, the sound of Lil Wayne on Q93 FM, as well as the shame of bringing a date to the movies when you had to sit in what was then (in more polite circles) referred to as “the Negro balcony.”

All this can bring to mind Jesmyn Ward’s “Salvage the Bones,” but where Ward is Faulknerian in her rhetorical sweep, Sexton maintains a cool, detached naturalism more reminiscent of Tayari Jones in “Leaving Atlanta.” Whether writing of black girlhood, the quotidian fears and hopes of mothering, or the lure of street life, she places her characters in the path of momentous choices while making it clear they have little to hope for. At the end of the day, it is mainly women like Jackie, “teetering between her narrow options,” who are left to pick up the pieces and wonder at their ability to cope. “What happened to the face of a broken woman?” Evelyn asks herself as she watches over her sleeping sister. “Did it turn to convey the loss or did it conspire with her heart to hide it?”

“A Kind of Freedom” attends to the marks left on a family where its links have been bruised and sometimes broken, but dwells on the endurance and not the damage. The force of this naturalistic vision is disquieting; it is also moving. One could say that it has the disenchanting optimism of the blues. Though her style differs sharply from Zora Neale Hurston’s sassy lyricism, Sexton looks upon her characters much as Janie views her life in “Their Eyes Were Watching God” — “like a great tree in leaf with the things suffered, things enjoyed, things done and undone.”