An analysis of more than 500 pairs of twins in grades seven to 12 found that twins who had sex at a younger age were not more likely than their counterparts who delayed having sex to participate in behaviors like vandalism, drug dealing and shoplifting.

Such findings call into question a main argument used to justify abstinence education, The Washington Post reported Sunday.

The conclusion of the research by led by Paige Harden, a doctoral candidate at the University of Virginia in Charlottesville, was drawn from data on 7,000 youths compiled by Ohio State Researchers.

However, the Ohio State team concluded those who had sex at an age earlier than average for their region were 20 percent more likely to have participated in delinquent behavior a year later.

Harden said the disparate outcomes resulted from the difference between causation and correlation: poverty or a willingness to take risks, for example, may make teens more likely both to have sex early and be delinquent, making it falsely appear that one causes the other.