About one in three high school-age youngsters in Utah have had sexual experience and about one in six is considered sexually active, according to a state study released this week. Those figures are far too high to be much comfort to parents, but one thing is clear: Those who abstain are in the majority. It simply isn't true that "everybody does it."

The figures come from a confidential survey done by consultants for the Governor's Task Force on Teenage Pregnancy Prevention. The results draw a useful behavioral map showing what youngsters are more likely to have sexual encounters.Teens who are at "high risk" generally share certain circumstances. These include (1) dating at an early age; (2) going steady, (3) the wrong kind of friends, (4) use of alcohol or drugs, and (5) no religious involvement. Those in the "low risk" group had the reverse of those situation.

There is nothing in that list that is a surprise. It amounts to the very same things that most parents try to warn their children about, and is made up of the items that frequently are a point of conflict between parent and child. Slightly less than half of the 839 teens surveyed fell into the high-risk group.

Yet youngsters in the high-risk category are 10 times as likely to become sexually active as low-risk teens. Those classified as high risk accounted for 92 percent of the young people who were sexually active.

Other factors that have an impact include: Teens who live with both parents were less likely to be sexually active. The same was true of those with three of more siblings; those who did well in school; those who took part in school extracurricular activities, and those planning to attend college.

But the biggest impact of all was having values that call for sexual abstinence. "Such values play a crucial role in helping teens avoid sexual activity," the report said.

Even among those teens in the high-risk group, those with some commitment to the moral value of abstinence kept out of trouble more often than those without such values.

Some so-called experts claim that teaching abstinence to teens is an exercise in futility and say that education efforts should focus on "safe sex" as a way to avoid teen pregnancies and disease.

But as the survey results show, the teaching of abstinence, properly fortified in other ways, is the most single effective approach. There simply is no adequate substitute.

If schools are going to have sex education programs, it's clear that such programs will have to be based on moral values if they are to have any real impact on behavior.