Skewed sex ratios leading to increase in crime

Throughout human history, young men have been responsible for the vast preponderance of crime and violence - especially single men in countries where status and social acceptance depend on being married and having children, as it does in China and India.

A rising population of frustrated single men spells trouble.

The crime rate has almost doubled in China during the past 20 years of rising sex ratios, with stories abounding of bride abduction, the trafficking of women, rape and prostitution.

A study into whether these things were connected concluded that they were, and that higher sex ratios accounted for about one-seventh of the rise in crime.

In India, too, there is a correlation between provincial crime rates and sex ratios.

In Bare Branches, Valerie Hudson and Andrea den Boer gave warning that the social problems of biased sex ratios would lead to more authoritarian policing. Governments, they say, "must decrease the threat to society posed by these young men.

"Increased authoritarianism in an effort to crack down on crime, gangs, smuggling and so forth can be one result."

Violence is not the only consequence. In parts of India, the cost of dowries is said to have fallen.

Where people pay a bride price - when the groom's family gives money to the bride's - that price has risen.

During the 1990s, China saw the appearance of tens of thousands of "extra-birth guerrilla troops" - couples from one-child areas who live in a legal limbo, shifting restlessly from city to city in order to shield their two or three children from the authorities' baleful eye.

And, according to the World Health Organisation, female suicide rates in China are among the highest in the world (as are South Korea's).

Suicide is the most common form of death among Chinese rural women aged 15-34; young mothers kill themselves by drinking agricultural fertilisers, which are easy to come by.

Journalist Xinran Xue thinks they cannot live with the knowledge they have aborted or killed their baby daughters.

Over the next generation, many of the problems associated with sex selection will get worse. The social consequences will become more evident because the boys born in large numbers over the past decade will reach maturity then.

Meanwhile, the practice of sex selection itself may spread as fertility rates fall and ultrasound scanners reach throughout the developing world.