Among the young people Regnerus and Uecker studied, the happiest women were those with a current sexual partner and only one or two partners in their lifetime. Virgins were almost as happy, though not quite, and then a young woman’s likelihood of depression rose steadily as her number of partners climbed and the present stability of her sex life diminished.

When social conservatives talk about restoring the link between sex, monogamy and marriage, they often have these kinds of realities in mind. The point isn’t that we should aspire to some Arcadia of perfect chastity. Rather, it’s that a high sexual ideal can shape how quickly and casually people pair off, even when they aren’t living up to its exacting demands. The ultimate goal is a sexual culture that makes it easier for young people to achieve romantic happiness  by encouraging them to wait a little longer, choose more carefully and judge their sex lives against a strong moral standard.

This is what’s at stake, for instance, in debates over abstinence-based sex education. Successful abstinence-based programs (yes, they do exist) don’t necessarily make their teenage participants more likely to save themselves for marriage. But they make them more likely to save themselves for somebody, which in turn increases the odds that their adult sexual lives will be a source of joy rather than sorrow.

It’s also what’s at stake in the ongoing battle over whether the federal government should be subsidizing Planned Parenthood. Obviously, social conservatives don’t like seeing their tax dollars flow to an organization that performs roughly 300,000 abortions every year. But they also see Planned Parenthood’s larger worldview  in which teen sexual activity is taken for granted, and the most important judgment to be made about a sexual encounter is whether it’s clinically “safe”  as the enemy of the kind of sexual idealism they’re trying to restore.

Liberals argue, not unreasonably, that Planned Parenthood’s approach is tailored to the gritty realities of teenage sexuality. But realism can blur into cynicism, and a jaded attitude can become a self-fulfilling prophecy. Social conservatives look at the contemporary sexual landscape and remember that it wasn’t always thus, and they look at current trends and hope that it doesn’t have to be this way forever.

In this sense, despite their instinctive gloominess, they’re actually the optimists in the debate.