Parents go to such lengths in part because Chinese culture has always emphasized success, but also for a more pressing reason: Traditionally, children support their parents in old age. With only one child to carry the load, parents’ fortunes are tied to their child’s, and they push (and pamper) the little ones accordingly. “In China, the term for a one-child family is a ‘risky family,'” says Baochang Gu, a demography professor at Beijing’s Renmin University who advises the Chinese government on the one-child policy. “If something happened to that child, it would be a disaster. So from the parents’ point of view, the spoiling is all necessary to protect them.”

http://www.psychologytoday.com/articles/index.php?term=pto-20080623-000004&print=1

Very resonant with the case I made in the Ending Poverty with Open Hardware talk, about how the pressure to large family size comes from the sheer number of kids you need to have to ensure 90% or 99% odds of having two live to adulthood in a high infant mortality society.