She disdains class elections now. "It's a lot of work," she says, "and the teacher is always pointing to you as a role model. If you get in trouble and get demoted, it's a big embarrassment." She loves Hollywood films—especially Star Wars and disaster movies—and spends hours online with friends discussing Detective Conan, a character from Japanese comic books. She intends to marry a foreigner because they are richer and more reliable.

Her parents no longer help with her homework; in spoken English she has surpassed them. They lecture her to be less wasteful. "When she was little, she agreed with all my opinions. Now she sits there without saying anything, but I know she doesn't agree with me," her mother said one afternoon in the living room of their new apartment, as Bella glared without speaking. "Our child-raising has been a failure." In China, there is no concept of the rebellious teenager.

Across Chinese society, parents appear completely at sea when it comes to raising their children. Newspapers run advice columns, their often rudimentary counsel—"Don't Forcibly Plan Your Child's Life" is a typical headline—suggesting what many parents are up against. Some schools have set up parent schools where mothers, and the occasional father, can share frustrations and child-raising tips.

At times educators go to extremes: At the Zhongguancun No. 2 Primary School in Beijing, vice-principal Lu Suqin recently took two fifth-grade boys into her home. "Their parents couldn't get them to behave, so they asked me to take them," she explains. "After they learn disciplined living, I will send them back."

Bella had one free day during the 2006 weeklong National Day holiday. Some of her extended family—seven adults and two children—took a trip to Tongli, a town of imperial mansions an hour's drive from Shanghai. Bella's father hired a minibus and driver for the trip; a friend had just been in a car accident and broken all the bones on one side of his body. Bella sat alone reading a book.

Developing China zipped past the window, city sprawl giving way to a booming countryside of fish ponds and factories and the three-story houses of prosperous farmers. Bella's mother indulged in the quintessential urban dream of a house in the country. "You have your own little yard in front," she said. "I'd love to live in a place like that when we retire."