BOOK REVIEW : PRIMITIVE PEOPLE <i> by Francine Prose</i> , Farrar Straus & Giroux, $20; 228 pages : ‘Primitive People’ Lacks Depth of Irony

Simone emigrates from Haiti to work as an au pair to the primitive people of the title.

These primitives are the superfine, sated, rich, white Americans who live on expensive properties in the Hudson River Valley, although they could as well live in any of dozens of privileged exurban spots around the United States.

Francine Prose’s “Primitive People” is a sharply written, often telling social satire that hinges on this presumable reversal. When Simone arrives at the mansion where she is to look after George and Maisie Porter, their mother, Rosemary, greets her with bright cultural condescension.

She gives her a house tour and takes her to the attic, where generations of mementos are kept, including the family portraits.

But the image--primitive Haitian is introduced to America’s gracious heritage--is pierced as soon as offered. Simone is highly educated, for one thing. For another, the mansion is in a state of sloppy neglect.

Rosemary wears a paint-stained fur coat--she is trying to become an artist--and her brightness is repressed hysteria. And the portraits have the eyes cut out; the children were allowed to use them to give an exotic touch to their paper dolls. So much for heritage when it crosses rainy-day whims.

Rosemary has a moment of compunction. Will Simone think that they practice some form of voodoo? Not exactly, the young woman reflects. “Mutilating paintings was very different from, say, decapitating a rooster. But for a moment she’d thought Mrs. Porter might practice some strange religion.

It is this strange religion--the rites, cruelties, greed, sleek barbarities and faithlessness of the well-off--that Prose so neatly sends up by showing it through the eyes of her young Haitian and by stippling the Hudson Valley with splashes of Haiti.

At home, Simone had come across the corpse of a man, eviscerated in some mutation of voodoo and politics. Here, in the woods, she bumps against a hanged sheep that figures somehow in the depraved practices of a rich neighbor.

In Haiti, life may be threatened by the Tontons Macoute ; here it is the hunters. Walking with the children, Simone is nearly killed. Sympathetically, Rosemary tells her of encountering two beefy hunters on her driveway:

“Never have I had such a sense of what kind of morning the deer were having. I dressed and took the first train to the city. I thought, crackheads may kill me but I’m sure they won’t tie me to the roof of their car. Well, pretty sure is what I thought. It’s all so neolithic.”

The savage parallels run much deeper. Simone left Haiti because her painter-lover took up with her best friend. Bit by bit, we come to see Rosemary as a far more wretched fellow-victim.

Geoffrey, her rich, patrician husband, left her when she began to sculpt instead of ministering to him. A poetically charming seducer--he almost manages to bed Simone--he allows virtually no money to his family. They live on junk food and baked beans.

In contrast, when the children come on weekend visits, Geoffrey gives them a lavish good time. “Me and the kids starving to death in a falling-down mansion,” the desperately, volubly witty Rosemary remarks, “while he spends the cash flow on luxury toys for his weekend discretional children.”

The cash flow also goes to fix up Geoffrey’s new place--splendidly, and with the advice of a decorator who is Rosemary’s best friend and confidante. There is a whiff of betrayal there; soon there will be more than a whiff. Rosemary will end as sacrificial victim, tentatively cutting her wrists in a failed suicide attempt.

At book’s end, she will be chattering acutely away in the bathroom as Simone sponges the blood off her naked body. The image loops back to Haiti; in a voodoo-tinged artistic stroke, Simone’s lover had incised a reproduction of Manet’s Nude “Olympia” with slashes of crimson.

For irony, the ending is appropriate. For tone, it is a little overdone; the one place where Prose’s inventiveness turns seriously heavy handed.

There are a couple of amusing but obvious set scenes--a Halloween costume party set in a mall and an ecological wedding in a stable--but otherwise, Prose’s writing is almost unfailingly pungent.

George and Maisie, the mournful child victims of the Porter household--they remind Simone of street children in Port au Prince--make touching portraits.

In many ways, “Primitive People” is strongly reminiscent of Jamaica Kincaid’s “Lucy,” published two years ago. There too, we are given ironic views of complacent American prosperity through the eyes of a Caribbean au pair .

“Lucy” had a strength, however, which Prose’s book lacks. Its protagonist was a complex and sinewy personage whose emotions and observations gave the book a binding force. Simone is gracefully but thinly conveyed. She makes a good window, but the ironic vision, ultimately, is more the author’s than hers.

Next: Elaine Kendall reviews “Keper of the Light” by Diane Chamberlain (HarperCollins).