WASHINGTON -- Recent books and studies seem to indicate disturbing sexual trends among evangelical Christians. And this time we're not talking about their pastors or political leaders. The new attention is on evangelical teenagers, who reportedly start sex earlier than their mainline Protestant peers.

One gleeful headline on an Internet site recently read: "Evangelical Girls Are Easy." That is not the way I remember it.

Now, in the cruel march of years, I have a child on the verge of joining the tribe of the teenager, and its rituals hold a sudden interest. In this circumstance, a parent has a choice between turning to sociology or turning to drink. So I called a bright young sociologist at the University of Virginia named W. Bradford Wilcox in search of consolation.

Wilcox argues, in a paper for the Russell Sage Foundation, that the facts are more complicated and more hopeful than the sniggering media caricature.

When the statistics on teen sexuality are controlled for social and economic factors, conservative Protestant teens first have sex at about the same time as their peers -- the average is midway through their 16th year. That is hardly comforting to conservative Protestant parents, who would expect more bang for the bucks they spend funding Sunday schools -- well, actually, less bang.

But these numbers shift when controlled for religious intensity. For those who attend church often, sexual activity is delayed until nearly 17, while nominal evangelicals begin at 16.2 years, earlier than the national average.

This trend is more pronounced on other measures of sexual behavior. Only 1 percent of conservative Protestants who attend church weekly cohabit, compared to 10 percent of all adults. (On this statistic, nominal evangelicals almost exactly mirror the nation.) Twelve percent of churchgoing evangelicals have children out of wedlock, compared to 33 percent of all mothers.

These facts, according to Wilcox, support some liberal claims and some conservative ones. Liberals are correct that economic and cultural factors matter greatly, sometimes more than individual belief. Teens with good life prospects and a strong sense of the future -- kids with economic and educational ambitions -- tend to avoid risky behavior such as drugs and early sex. Without those prospects, the temptation is strong to live for the moment.

The facts also support a basic conservative belief: that it is difficult for teens to be moral alone. Wilcox argues that teen sexual behavior can be influenced -- that teenagers can be more than the sum of their hormones. But responsible behavior requires both "norms" and "networks." An intellectual belief in right and wrong is not sufficient. Teens require a community that supports their good choices, especially in times of testing and personal crisis. "Kids who are embedded in a social network with shared norms," he concludes, "are more likely to abide by them."

Sociologist Peter Berger calls these networks "plausibility structures" -- sources of authority that do more than lecture or shame; they define the meaning of common sense. When institutions such as religious groups, families, government and the media send a strong and consistent message -- smoking is stupid, driving under the influence is criminal, teen pregnancy is self-destructive -- we have sometimes seen dramatic changes in behavior. Teen pregnancy and birth rates in the United States, for example, have declined by about one-third since the early 1990s.

These messages of responsibility are often reinforced by tight-knit religious communities, but they are not owned by them. Wilcox notes that American liberal elites often "talk left and walk right, living disciplined lives, and expecting their children to do the same, even when they hold liberal social views." Divorce rates among college-educated Americans, he points out, have fallen since the 1980s, as it became more evident that casual divorce did not serve the long-term interests of their children.

The decisive role of authoritative communities in determining individual behavior should not surprise conservatives. Conservatism teaches that individuals are not inherently good and so must be carefully civilized. They need social structures and networks that foster duty and discipline and define those commitments as common sense. In "The Quest for Community," Robert Nisbet warned: "Release man from the contexts of community and you get not freedom and rights but intolerable aloneness and subjection to demoniac fears and passions."

It would be nice if teen sexual behavior could be automatically changed by an abstinence lecture or a sermon. Setting those norms and expectations, however, is a small part of a larger cultural task. Moral men and women need moral communities.