Can adults write about children better than children can? Do adults know more about children than children do? Daisy Ashford, the 9-year-old author of “The Young Visiters” (1919), amused readers not just with her misspellings and her naiveté (she was trying to write a Victorian novel, like the ones she had read), but with her worldview, in which human consciousness is limited to country visits and absurd misunderstandings.

But though children may not know how to communicate it, their experience is just as broad and deep as our own. Or so novelists who want to fill out that experience claim, at least. In his preface to “What Maisie Knew” (1897), a novel about a Victorian-era divorce, Henry James mounts a strong defense for writing from the child’s point of view. “Small children,” he writes, “have many more perceptions than they have terms to translate them; their vision is at any moment much richer, their apprehension even constantly stronger, than their prompt, their at all producible, vocabulary.”

In “December” (Knopf, 239 pages, $23.95), her second novel, Elizabeth Hartley Winthrop dramatizes this lag between childish perception and its expression, making the perception itself an overwhelming barrier to any communication at all. She not only tells parts of her story from a child’s perspective, she also makes that child a genuinely silent one. Isabelle Carter, an 11-year-old private school student from the Upper East Side, decided to stop speaking one leap-year morning: “That first day had been February 29, 286 days ago. It wasn’t a real day, anyway, she’d figured, a day not to get out of bed, to eat, to drink, to speak.” Now it is December, she is doing her schoolwork from home, and her worried parents are desperate to explain what seemed, at first, merely to be the first stages of adolescence, but now, after 10 months, threatens their temper as a family.

Isabelle’s silence was not planned. But what started as a whim — indeed an adolescent protest — became a habit. Isabelle “has lost control of her control,” as Ms. Winthrop puts it. From the start, Ms. Winthrop makes clear that Isabelle’s chief problem is her parents — specifically, the insincerity of their own talk. Like Maisie, Isabelle becomes a vehicle for exploring the lives of her parents.

Well-intentioned and reasonably committed to each other, her parents are not designed for conflict. Wilson Carter is a good father, a weekend tinkerer who loves to distract himself. Once the novel’s crisis kicks in — Isabelle’s school will not accept her January re-enrollment if she cannot return to class — he latches on to the idea of a trip to Africa, sure that this will cure his child. Ruth Carter, who has given up her legal practice to care for her willfully disabled child, is a nitpicker and a faultfinder, and easily the more villainous of the two parents. But if she causes Isabelle more distress than Isabelle’s father, she is only a study of a still-sympathetic type, the mother who tries too much to understand her daughter — and in the process simplifies her.

Other young American writers might have made this family into a grotesque, an exaggerated study in middle-class bleakness, or perhaps a condescending experiment in pathos. But from the novel’s first set piece — Wilson’s annual birthday dinner at Luigi’s, a restaurant near the Carters’ country house — Ms. Winthrop treads the path of banality with a straight face. She does not seem forgiving so much as fair: This is how we live, and if our daughter stopped talking, this is how awful things would get.

Isabelle’s silence began not long after her parents had a particularly pointless argument about boredom. “There’s no excuse for being bored. Bored, Wilson, is a boring word,” said Ruth. “And that,” Wilson answered, “is a tired cliché.”

Isabelle, meanwhile, lives a life of transfixed visual wonder. A compulsive sketchbook artist, she fulfills James’ characterization of children — “their vision is at any moment much richer” than ours. She lies in bed, staring at her white ceiling, anxiously contemplating nothingness, and notes philosophically that “White to her isn’t white at all … She couldn’t begin to name all the colors she sees in the ceiling now.”

Though obviously gifted, Isabelle stands for all young people who sometimes feel more perceptive than they can communicate. Most of the problems caused by her silence — confused neighbors, a shoe salesman unnerved by her stare, impatient shrinks — could have been caused by any teenager’s coltish stubbornness. The central conceit of silence only lends drama to what is fundamentally a dispassionate description of regular life on the Upper East Side.

Ms. Winthrop’s first novel, “Fireworks,” displayed a similar dynamic, using a deceased child to anchor a less-than-melodramatic character study. In “December,” the heavy pace of description sometimes works against the always re-forming web of anxiety and parental dispute, but in the end Isabelle’s cure comes not through any dramatic process, but all of a sudden, at random. It’s a rabbit out of a hat, and this seems right. For the plot of this novel is primarily a way of, heroically, keeping our eyes open through a dinner at Luigi’s. Ms. Winthrop makes us feel at home there.

blytal@nysun.com