A Theory Revisted (What Teen Sex Actually Does)

Think there's a correlation between teen sex and becoming a juvenile delinquent? Well, a recent study has but that belief into doubt.

It all started with the initial study:

The latest example started when Dana Haynie, a sociologist at Ohio State, and her then-graduate student, Stacy Armour, published a study in February in the Journal of Youth and Adolescence. They analyzed data collected from more than 7,000 children as part of the National Longitudinal Study of Adolescent Health, a federally funded survey that in 1994 began gathering information about the health-related behavior of U.S. schoolchildren who were then in grades seven through 12.

Haynie and Armour divided the children into three groups based on when they first had sex: when they were younger, about the same age or older than the age at which most of their local peers lost their virginity. (It varies by region, but on average, U.S. children lose their virginity at age 16.) They also compiled information on graffiti-painting, shoplifting, drug-selling and other "problem behaviors" by those young people in later years.

Their conclusion: One year after losing their virginity, children in the early category were 20 percent more likely than those who started having sex at the average age to engage in delinquent behavior, even when several other relevant factors such as wealth, race, parental involvement and physical development were taken into account.

Paige Harden from the University of Virginia (in Charlottesville) saw things differently and ran her own tests, using the same data:

Suspecting such an error in the Haynie study, Harden and three colleagues, including her adviser, Eric Turkheimer, an expert in behavioral genetics, studied more than 500 pairs of twins in the same national survey analyzed by the Ohio team. Because twin pairs share similar or identical genetic inheritances (depending on whether they are fraternal or identical) and the same home environment, twin studies are useful for seeing through false cause-and-effect relationships.

The team looked at identical twin pairs in which one twin initiated sex younger than the other, then team members tallied subsequent problem behaviors. If sex really adds to the chances of delinquency, then early-sex teens should end up delinquent more often than their later-sex twins.

"It turns out that there was no positive relationship between age of first sex and delinquency," Harden said.

So what's Harden's overall conclusion?

The new study "really calls into question the usefulness of abstinence education for preventing behavior problems," Harden said, "and questions the bigger underlying assumption that all adolescent sex is always bad."