Mormon teens pray more, have sex less and in general rank No. 1 when it comes to the effect of religion on their lives, according to a just-released study of American adolescents.

"The story we tell about Mormon youth is not that all is well, but compared with other teens they're more knowledgeable about their faith, more committed to their faith and have more positive social outcomes associated with their faith," says John Bartkowski, who helped conduct research for the National Study of Youth and Religion.

The study, conducted at the University of North Carolina, has just been released in "Soul Searching: The Religious and Spiritual Lives of American Teenagers," published by Oxford University Press.

The survey found that more than 80 percent of U.S. teens believe in God and two-thirds attend a religious service at least once a month. But teenagers who belong to The Church of Jesus Christ of Latter-day Saints outrank their peers when the questions get more specific.

"The LDS Church asks a lot of its teenagers, and it would appear that, more often than not, they get it," concludes researcher Steve Vaisey.

"I'm not saying they're all perfect," adds the study's lead author, UNC sociology professor Christian Smith. "I'm not trying to idealize Mormon kids." But when belief and "social outcomes" are measured, he says, "Mormon kids tend to be on top."

The four-year study included interviews with 3,370 randomly selected teenagers, ages 13 to 17, in 45 states, and follow-up face-to-face, in-depth, interviews with 267 of them. There were questions about church attendance, scripture reading, the importance of faith in making daily decisions, as well as questions about "risky" behaviors such as pot smoking, lying and drinking.

The survey relied on self-reporting, a fact that could conceivably skew the data. But researcher Bartkowski says he trusts the answers.

"I had kids admit all kinds of behavior," he said. "And where Mormon teens are concerned, one of the principles of the faith is honesty."

Mormon teens were found more likely to:

• hold religious beliefs similar to their parents' (73 percent).

• attend religious services once a week (43 percent compared to 26 percent for Conservative Protestants, who, on the other hand, were slightly more likely than Mormons to attend church more than once a week).

• rate the importance of religious faith in shaping their daily life as "extremely important" (43 percent).

• engage in fasting or some other form of self-denial (68 percent).

• have no or few doubts about religious beliefs (91 percent).