Maybe Grounding Your Teenager Isn’t the Best Way to Make a Point


There’s a polite way of saying everything, and then there’s a blunt way. Take, for example, this well-mannered description of the teenage brain, from a study published today in the journal PLOS Computational Biology: “Adolescents are often characterised as prone to engage in suboptimal decision-making,” the study authors write, “[which] can sometimes result in negative real life outcomes.”

Indeed. This may be the gentlest possible way of explaining what anyone who’s had, or been, a teenager knows to be true: Teens can be dumb, and all the crazy things happening in their brains can lead them to do some pretty dumb stuff. Neuroscientist Abigail Baird has called the onset of adolescence a “second toddlerhood,” a stage of life that “involve[s] major changes to the cognitive processes that support abstract thinking.”

Chief among those changes is a growth spurt in the prefrontal cortex, which governs planning, mood, and impulse control. Over the course of adolescence, the brain prunes away the excess synapses of that region, allowing the ones that remain to more efficiently process information. This process continues until the mid to late 20s — around the same time that the brain’s reward system, which kicks into hyperactive gear for the teenage years, begins to settle down.

In the meantime, these neurological changes leave teens more attracted to risk and less inclined to fully process the consequences of their actions — which, combined with raging hormones, high-school politics and peer pressure, and struggles to assert their independence from their families, can make for a perfect storm of terrible choices. Whether they learn from those choices, though, is another story — and the PLOS study suggests that punishment may not be the best way to help them do it.

For the study, 18 teenagers (aged 12 to 17) and 20 adults (18 to 32) played a game where they had to choose between two different symbols, using correct choices to rack up as many points as they could. Each round was one of two setups: In the “reward” condition, choosing the correct symbol gained them a point and choosing the wrong one did nothing; in the “punishment” condition, the right answer did nothing and the wrong one meant losing a point. The meaning of each symbol stayed the same, so that as the rounds progressed, players could learn which ones to click and which ones to avoid.

In theory, at least. When the researchers analyzed the players’ performances, they found an important distinction between the two age groups: “Adolescents … learned preferentially to seek rewards rather than to avoid punishments, whereas adults learned to seek and avoid both equally,” they wrote. In other words, the adults adapted their choices based on whether they gained or lost points; the teens, meanwhile, chased the gains, but didn’t appear to take past point-docking mistakes into account as they learned which symbol had which meaning. In some cases, the researchers also told players after each round what would have happened if they’d chosen the other symbol; learning about these alternative scenarios improved the performance of the adults, but not of their younger counterparts.

As the authors themselves note, it’s impossible to draw bulletproof conclusions when the line between adolescence and adulthood is so roughly drawn: Age 18 “it is an inevitably arbitrary cut-off,” they wrote, “and as such, it is possible that there might be developmental changes in task performance during early adulthood that we cannot detect,” especially in such a small sample size.

Practically speaking, the study does seem to mirror the iterative process of figuring out real life: You do something, see whether it gets rewarded, factor that into your decision-making; then you do something else, see whether that gets rewarded. Most of the time, though, this is tempered by what psychologists call “loss aversion” — there’s a trove of behavioral research suggesting that people respond more strongly to the threat of a loss than the possibility of a gain. The negative effect of a punishment, along those same lines, ought to outweigh the of an equal-sized reward — the sting of losing $20, for example, is bigger than the joy of winning the same amount of money.

But in adolescence, this study suggests, the pattern might be thrown out of whack, with the promise of reward outranking the risk of loss as the primary motivator — a finding that may prove helpful for hapless adults looking to transform themselves into teen whisperers. “It may be useful for parents and teachers to frame things in more positive terms,” study co-author Sarah-Jayne Blakemore, a neuroscience professor at University College London, said in a the study’s press release. “For example, saying ‘I will give you a pound to do the dishes’ might work better than saying ‘I will take a pound from your pocket money if you don’t do the dishes.’ In either case they will be a pound better off if they choose to do the dishes,” but one of those statements will nonetheless be more appealing, and therefore more effective, than the other. That’s not to say that a no-rules free-for-all is the way to go — just that there’s a polite way of saying everything and a blunt way, and sometimes, the gentler tack may also be the way to get things done.