A kind of ‘blowback’ on a new generation of young men in China from that culture’s “customary preference for boys.”

According to the Association of American Physicians and Surgeons, sex-selection is becoming a problem in the US too.

As many as 200 million girls may have been killed worldwide in this way, mostly in Muslim and Asian countries. The rate is increasing because of ultrasound technology that permits sex identification around 18 weeks.

Using data from the U.S. 2000 census, researchers have noticed a male sex bias in U.S.-born children of Chinese, Korean, and Asian Indian parents. The effect of birth order is striking. There is a normal sex ratio, 106 girls to 100 boys, for first births. If the first birth is a son, the sex ratio of second children is also normal. But if the first child is a girl, the second child tends to be a boy. And if the first two are girls, the third is 50% more likely to be a boy

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