18 May 2011

Twin-study findings conflict with sex ed dogma

by Kate Melville

Current sex education curricula recommend abstinence as a way of reducing sexual risk-taking, but a new study appearing in Psychological Science indicates that early sexual initiation has no effect on an individual's risk-taking behavior.

University of South Florida psychologist and study author, Marina A. Bornovalova, said she originally set out to test the assumption that delaying first sex reduces sexual risk-taking - and with it unwanted pregnancies and sexually transmitted diseases.

Bornovalova and her co-researchers looked at more than 1,000 pairs of identical and fraternal twins enrolled in the longitudinal Minnesota Twin Family Study. The twins were questioned on biological, social, and psychological factors at age 11. Then, at age 24, they were asked about the risks they were taking in their sex lives. The key factor in the study was that in some pairs, one twin had early sex and the other didn't.

Numerous runs of the data led to the same conclusion, said Bornovalova; "You take two twins who share 100 percent of their genes. One has sex at 15 and one at 20. You compare them on risk-taking at 24 - and they don't differ."

She added that a correlation between early sexual initiation and later sexual risk-taking does exist; "But, as a causal factor for sexual risk-taking - multiple partners, drug and alcohol use during sexual encounters, or unprotected intercourse - it doesn't really matter whether you delay sex or not." The findings, Bornovalova says, should spark serious rethinking by sex educators.

Rather than early sexual initiation, the researchers think sexual risk-taking stems from a combination of genetic factors - such as the strong inherited tendency to be impulsive or anti-social - and environmental ones, such as poverty or troubled family life.

Bornovalova stresses she is not advocating sex at a very early age. "But if our goal is to reduce sexual risk-taking, we need to be focusing on something else," she suggests. "More study is needed to zero in on what that something else is. But for now, one thing should be clear to the people writing sex ed curricula: whatever is causing sexual risk-taking, it is not early sexual initiation."

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Source: Psychological Science