Now, Why Teens Are Stupid

Blame their brains. What else?

Scientists at Temple University recently took on the task of figuring out the “why” behind what we all know is a given: Teenagers will do dumber things when they’re in groups than when they’re by themselves. The principle is the driving force behind laws that limit the number of other teens allowed in a car piloted by a tyro driver. Not coincidentally, Temple’s researchers used driving, albeit of the video-game sort, in their study. The scientists scanned the brains of 14 teens ages 14 through 18, 14 college students, and 12 young adults while they played a video game in which they vied for cash prizes based on how long they took to finish. In the course of the game, players had to decide whether to slow down and stop at yellow lights—decreasing their risk of crashing—or speed up for them in pursuit of the prize, despite the risk.

Participants played the game two ways: while they were alone, and while they’d been told two of their friends were watching from the next room. In college students and young adults, there weren’t any measurable differences between the results. But when it came to the young teens, the presence of friends—even unseen, unheard-from friends secluded behind a wall—caused them to run 40 percent more yellow lights and crash 60 percent more often. And having friends on hand lit up the areas of the teenagers’ brains associated with rewards, indicating that they became more attuned to the potential payoff for taking risks and less aware of the possible negative consequences—a result not seen in the scans of college students and young adults.

This won’t come as a surprise to any parent who’s ever watched, heart in throat, while a son or daughter gets into a car driven by a peer for the first time, and pulls away from the curb. But the study could provide some solace for parents who’ve lost teens who took part in risky behaviors while in the presence of their peers, and, just as importantly, to the families of those peers. The friends of lost teens didn’t have to be egging them on, or distracting them, or, really, doing anything at all. The Temple study shows: They only had to be there.