Gen Goody-Goody?

Teens sober, celibate

Gen X was stereotyped as a bunch of apathetic underachievers. Millennials have been branded as narcissistic overachievers. What reputation will the post-millennial cohort, known as "Gen Z," develop?

If early signs are any indication, these kids may be seen as the most goody-goody generation to come of age this side of the 8-track player's extinction.

According to the Youth Risk Behavior Surveillance System, a study the U.S. Centers for Disease Control and Prevention has been conducting since 1991, last year's levels of high school sex, smoking, and boozing were all down. In 2015, around a third of the high school students surveyed said they had smoked cigarettes in the preceding 30 days—down from 70.1 in 1991, 70.4 percent in 1999, and 41 percent in 2013. Smokeless tobacco use also decreased, from 11.4 percent in 1995 to 7.3 percent in 2015. And drinking, too: Just 63.2 percent had ever tried alcohol, down from 81.6 percent in 1991 and 75 percent in 2007.

Maybe the kids are just choosing to get intoxicated in different ways? Nope: Use of hallucinogens, meth, cocaine, ecstasy, and heroin have all dropped, too. And while the percentage who had tried marijuana at least once was up around seven percentage points from 1991, it has decreased nine points since the late '90s.

Teen sexual activity also continues to decline, with just 41 percent of high schoolers surveyed last year reporting ever having sex, down from 54.1 percent in 1991 and 46.8 percent in 2013. Millennial and Gen Z students were also more likely than kids before them to use condoms and other forms of birth control than kids were in the '90s and early aughts.