Illustration by O.O.P.S.

This column appears in the Feb. 5 issue of The New York Times Magazine.

Every few years, parents find new reasons to worry about their teenagers. And while there is no question that some kids continue to experiment with sex and substance abuse, the latest data point to something perhaps more surprising: the current generation is, well, a bit boring when it comes to bad behavior.

By several noteworthy measures, today’s teenagers are growing increasingly conservative. While marijuana use has recently had an uptick, teenagers are smoking far less pot than their parents did at the same age. In 1980, about 60 percent of high-school seniors had tried marijuana and 9 percent smoked it daily. Among seniors today, according to the University of Michigan’s Monitoring the Future survey, which has tracked teenage risk behaviors since 1975, 45.5 percent have tried the drug and 6.6 percent are smoking it frequently.

Adolescent use of alcohol, tobacco and most illegal drugs is also far lower than it was 30 years ago. In 1980, about a third of 12th graders had smoked in the past month; today that number has dropped to fewer than 1 in 5. Teenage alcohol use has reached historic lows. In 1980, 72 percent of high-school seniors said they had recently consumed alcohol, compared with just 40 percent in 2011. In 1981, about 43 percent of 12th graders had tried an illegal drug other than pot; in 2011 that number fell to 25 percent.

Today’s teenagers are also far less likely to have sex or get pregnant compared with their parent’s generation. In 1988, half of boys 15 to 17 had experienced sex; by 2010 that number fell to just 28 percent. The percentage of teenage girls having sex dropped to 27 percent from 37.2 percent, according to the latest data from the U.S. Centers for Disease Control and Prevention.

Health officials say drug use and teenage pregnancy rates are higher here than most other developed nations, but most trends are improving. What about TV shows like “Teen Mom” and “Gossip Girl” that suggest adolescence is dominated by sex and booze? “There is a lot more media hype around the kids who are raising hell,” says Dr. John Santelli, president-elect for the Society for Adolescent Health and Medicine. “There are a lot of kids who are pretty responsible.”

Nobody knows exactly why sex and drug use has declined among teenagers, but there are a number of compelling possibilities that may have contributed. The last three decades have included a rise in the drinking age to 21; a widespread fear of H.I.V.; and legal challenges that stymied tobacco marketing. And while cellphones and Facebook have created new ways for teenagers to stir up trouble, they may also help parents monitor their children. Still, today’s children have found ways to rebel (think energy drinks and sexting) that aren’t tracked in national surveys. “The entire purpose of the teen years is to push the envelope,” Ann Shoket, editor of Seventeen magazine, said. “The fact of the matter is every generation of teens freaks their parents out in some way.”