Miley Cyrus scandalized even the liberal audience of this year’s MTV Video Music Awards. What was it about her performance that hit such a nerve? Other entertainers have pushed the envelope with scant clothing and raunchy gestures. Miley, who rose to fame as Walt Disney’s Hannah Montana, made us particularly uncomfortable because she’s a “good girl gone bad.”

The good news is many of Miley’s peers aren’t adopting her behavior or the easy-living attitudes expressed in her summertime single “We Can’t Stop.” In fact, a survey released this month shows that 65 percent of Harvard freshmen are virgins. Good for them.

Notably, the Harvard crowd is different from the population at large in many ways. Not only are they less likely to have hooked up in high school, but they are more likely to have scored perfectly on the SAT. The two are connected. These driven youth have high hopes for their futures and aren’t allowing risky behaviors to get in their way.

They recognize that being “good” is smart, especially for girls in their high-school and college years. Waiting until later in life to become sexually active reduces the risk of disease, infections, emotional turmoil, and, most important, unwed motherhood.

There is a constant wringing of hands in the United States about the gender wage gap, the economic plight of women, and the feminization of poverty. Well, guess what’s the counterpart to female poverty? Single motherhood.

Single motherhood cuts both ways: First, of course, it drives female poverty by giving unmarried women the added responsibility of caring for another life. On the other hand, single motherhood is often driven by poverty: Sadly, girls growing up in at-risk homes tend not to dream of Harvard, economic success, or rewarding careers. Instead they seek their identity and security in having a child too soon. It’s a vicious cycle.

So forgive the abstinence advocates when we appear prudish. We simply want girls of all backgrounds to have the opportunity that surely nearly every Harvard woman will have: the chance to finish school and establish a stable relationship (ideally marriage) before welcoming her first child.

People may be tempted to mock the Harvard freshmen, doubling down on stereotypes about nerds and bad social skills. But who is better off, ultimately, when they wait to have children until after they are married and educated? Who end up richer and more secure in life? It’s the good girls, and not just at Harvard, but in all walks of life.

In our culture, instead of just focusing on the Miley Cyruses, we should recognize and applaud the many young adults who are making the right decisions. Teen pregnancy declined by 42 percent from 1990 to 2008, owing in part to the fact that teens are waiting longer to start having sex. In the period from 2006 to 2008, among unmarried girls ages 15 to 19, only 11 percent had had sex before age 15, compared with 19 percent in 1995.

Making sure that people — particularly young people — know these facts and figures can play an important role in encouraging better behavior. Too much of our culture — from headlines in Cosmopolitan magazine to TV shows like The Secret Life of the American Teenager — sends the message that promiscuity is ubiquitous and a rite of passage toward adulthood. But it’s not. Those who do take sex seriously are in good company.

Miley Cyrus can do as she chooses on stage and off. But she has influence as a pop-culture icon. Rather than encourage behaviors that plague the low-income youth of her cohort, she should acknowledge that behaving badly comes with consequences, and that being “good” — or self-controlled — is being smart.

— Hadley Heath is a senior policy analyst at the Independent Women’s Forum.