China's "Little Emperors" -- the generations of only-children born under the government's "one-child" policy -- are living up to their name.

A study in the journal Science has found that compared with people born in the years before China launched its population-control policy, those born after were less conscientious, more risk-averse and less inclined to compete with -- or cooperate with -- others. In short, a nation forged by collectivism, hard work and deprivation has created a generation of young adults that could be its undoing.

In China, the legions of children who commanded the undivided attention and resources of their parents have long been viewed with suspicion. But as they matured into adulthood, the "Little Emperors" could afford to roll their eyes at their fretting elders: Western research has consistently shown that only-children -- singletons, as demographers call them -- are no more selfish, lazy or maladjusted than their peers with siblings.

But China's elders, apparently, were right. Initiated in 1979, the one-child initiative has had its most dramatic effects in families living in China's urban centers, such as Beijing and Shanghai. These children are likely to make up the vanguard of the country's future government and business elites, experts say, so their behavioral attributes are a matter of national -- and international -- importance.

As the "Little Emperors" grew to adolescence, studies largely failed to document what grandparents, teachers and eventually employers would come to believe with conviction: that the children of the one-child policy were spoiled, selfish and lazy. At urban job fairs and in help-wanted ads, employers have been known to discourage singletons from applying. A group of delegates to the Chinese People's Political Consultative Conference called on the government to scrap its one-child policy in 2007, citing "social problems and personality disorders in young people."

The mismatch between widespread attitudes in China and hard data was a puzzle to economists at Australia's Monash University -- one of whom emigrated from China and has a daughter born there under the one-child policy.

Lisa Cameron and Xin Meng recruited 215 people born in 1975 and 1978, before the policy began, and 208 people born in 1980 and 1983, after it went into effect. Among the older group, 55 percent had at least one sibling, compared with 15 percent in the younger group.

Compared with the adults born before the one-child rule, those born after were less likely to be altruistic in a game in which the player dictates how to split a pot of money. They exhibited less trust and trustworthiness and were more likely to favor a safe bet over a high-risk, high-reward proposition.

Cameron and Xin were cautious about extending their findings beyond China. But when stereotypes are similar across cultures, Cameron said, research findings that show those stereotypes to have some basis in reality often hold true across cultural bounds.