U.S. Births Hint at Bias for Boys in Some Asians

The trend is buried deep in United States census data: seemingly minute deviations in the proportion of boys and girls born to Americans of Chinese, Indian and Korean descent.

In those families, if the first child was a girl, it was more likely that a second child would be a boy, according to recent studies of census data. If the first two children were girls, it was even more likely that a third child would be male.

Demographers say the statistical deviation among Asian-American families is significant, and they believe it reflects not only a preference for male children, but a growing tendency for these families to embrace sex-selection techniques, like in vitro fertilization and sperm sorting, or abortion.

New immigrants typically transplant some of their customs and culture to the United States - from tastes in food and child-rearing practices to their emphasis on education and the elevated social and economic status of males. The appeal to immigrants by clinics specializing in sex selection caused some controversy a decade ago.

But a number of experts expressed surprise to see...