China's iPad Generation - By Deborah Jian Lee and Sushma Subramanian

On a sweltering night in July 2011, 17-year-old Zhang Juanzi arrives at her farmhouse in the remote village of Silong in Hunan province. Despite the cramped 12-hour van journey from Shenzhen, the young girl bounds past the wooden doors to wake up her 5-year-old brother, Zhang Yi, whose face scrunches in the flickering light. He is thrilled by her arrival, but when he sees his mother, Huang Dongyan, he recoils into his sister's arms. He will not look at Huang, who is squealing at him, begging him to say "Mommy."

After many minutes of this game, Huang, exasperated, pulls out a plush animal. "Say 'Mommy,'" she lilts. "Mama," he says, snatching his new toy. Huang had hoped for a better start to her visit. She will soon deliver some life-altering news to her son: After this visit, she will move him to Shenzhen, the city where she, along with about 12 million other migrants, maintain their fragile economic circumstances by producing shoes, iPads, and other exports sold all over the world.

Huang and her son have a strained relationship, one damaged by Huang's absence. It has been months since they last saw each other. Her son seems to view Huang as a stranger who visits once or twice a year and demands his affection. Huang blames the country's housing registration policy, or hukou system, for their broken bond. The hukou system denies social benefits to China's some 150 million rural migrant laborers who move to urban areas for work. Because of this policy, migrant workers like Huang are forced to leave their children behind in the village to receive schooling, health care, and other necessary services.

Roughly 58 million children like Yi are left in China's countryside without their parents. This might be economically necessary, but it is emotionally disastrous: Chinese University of Hong Kong researchers found that adolescents left behind in their villages were more likely to engage in risky behavior such as binge drinking, and have increased thoughts of suicide. The children separated from their migrant parents are also more likely to have learning disabilities and psychological problems, says Zhang Ping, a researcher at the Psychological Science Institute of Guangdong Province. In school, they lack focus; at home they lack guidance.

Before Huang brings her son with her to Shenzhen, she wants to bridge the emotional distance. But on this morning in July, she can't seem to attract his attention. "Let mommy feed you," she says, but Yi has already left the table, breakfast of chicken feet in hand, and is prancing toward his sister.

Yi's only contact with his mother has been by phone, a few times a month. Parenting by phone is the norm for this generation of migrants, says researcher Zhang. Many migrant parents, including Huang, ask about school and the family but little else. This limited scope of interest makes it difficult to establish a real bond, which is formed when parents help their kids through problems. And the aging, ailing grandparents, typically charged with rearing a brood of grandchildren, struggle with the physical demands of farming the land, maintaining the house, and raising a new generation. "The changing speed of China is unprecedented," Zhang says. "For grandparents living in an isolated village, their knowledge of the world outside is too far behind what is really happening in Chinese society."

Later, when Yi asks his sister to clip his nails, Huang insists on doing the task. "You listen to your sister, but not your mother?" Huang teases, with pain in her voice, as her son ignores her.

Wang Yanlin, a shy, rosy-cheeked 17-year-old, says she often felt depressed and abandoned, even though she understood why her parents took jobs hundreds of miles away from their home in rural Hunan province. Her father, a construction worker, and her mother, a factory cleaner, left her as an infant to work in the industrial city of Dongguan, which borders Shenzhen. While her parents called home several times a month, it wasn't enough to forge real closeness.

Wang's depression grew worse when her peers, also children of migrant workers, started physically attacking her. "Every kid who had parents could say, 'I will tell my parents, and they will teach you a lesson,' but for me, when I was bullied, I couldn't say that," she says. Once, on a desolate country road, a group of kids hurled rocks at her. One heavy stone fractured her leg and knocked her to the ground. She lay there until she found the strength to hobble home. "When I told my grandmother, she told me that it was my fault, that I shouldn't hang out with those people," Wang says. "That was one of my saddest memories."