The New Sciencd of the Teenage brain

October 14, 2011, 7:24 PM

Teen Spirit Smells Like . . . Victory!

By DEAN ROBINSON

If you have — or have ever had — a teenager in your home or, really, if you have ever known a teenager, then chances are there’s been an occasion when you wondered, What was he thinking? (Or if he was thinking.) That’s why you should check out National Geographic’s October cover article by David Dobbs, “The New Science of the Teenage Brain.” It’s full of fascinating things. Even Shakespeare is enlisted to sum up the problem of teenagedom, through a character who says, of 10- to 23-year-olds, “There is nothing in the between but getting wenches with child, wronging the ancientry, stealing, fighting.” The bard neglects drinking, drug doing, driving while drinking or drug doing, cutting classes, indulging all sorts of cyber shenanigans, playing too much of that damn “Halo” video game — wait, I sound like the ancientry, don’t I? — but you get the idea. Teenagers are crazy.*

Basically, the fully grown brain (size-wise) is rewiring itself between the ages of 12 and 25, as myelin insulates the nerve fibers used most frequently, and the unused fibers are left to atrophy. This system upgrade means “we get better at integrating memory and experience into our decisions. . . . [and] the frontal areas develop greater speed and richer connections, allowing us to generate and weigh far more variables and agendas than before.” (Improved neural efficiency is good for more than thought processes, of course. Think sports, for example. Myelination is at the heart of Daniel Coyle’s cover article for Play magazine in 2007, which led to his book “The Talent Code: Greatness Isn’t Born. It’s Grown. Here’s How.” Upshot: get your kid swinging a bat or a racket or a club early and often and with focus. If you’d prefer a Mozart, substitute piano for sporting goods.)

But I guess all that work going on in the cranium means things are unsettled up there for years. (I imagine it’s like this: If you want to replace the knob-and-tube wiring in an old house — the kind that burns a place down — you have to make a mess of the homestead for a while.) As Dobbs writes, capturing the good and bad of the teenage brain’s maturation:

When this development proceeds normally, we get better at balancing impulse, desire, goals, self-interest, rules, ethics and even altruism, generating behavior that is more complex and, sometimes at least, more sensible. But at times, and especially at first, the brain does this work clumsily. It’s hard to get all those new cogs to mesh.

This realization has been dawning for a while now, since teenagers started having their brains scanned and studied in the 1990s. What’s emerging more recently is the recognition that this state of affairs confers evolutionary advantages; it isn’t only some byproduct phase to be endured. The allure of novelty, thrills and intense social interaction, combined with the flexibility afforded by late myelination, opens young people up to the world. New horizons are sought; useful experiences are had. Dobbs again:

The move outward from home is the most difficult thing that humans do, as well as the most critical — not just for individuals but for a species that has shown an unmatched ability to master challenging new environments. In scientific terms, teenagers can be a pain in the ass. But they are quite possibly the most fully, crucially adaptive human beings around. Without them, humanity might not have so readily spread across the globe.

I have to admit I’m having trouble reconciling this new general way of thinking about teenage wasteland with some particulars. Let’s say one teen didn’t start his required summer reading — four novels! historical source materials! statistics crypto-whatever! — until days before school began . . . um, that means he’s adapting himself for what, exactly?

*Here’s an evocative description of these years from the point of view of Lola Cabral, a character in Junot Díaz’s novel “The Brief Wondrous Life of Oscar Wao”:

I was the tallest, dorkiest girl in the school, the one who dressed up as Wonder Woman every Halloween, the one who never said a word. People saw me in my glasses and my hand-me-down clothes and could not have imagined what I was capable of. And then when I was twelve I got that feeling, the scary witchy one, and before I knew it my mother was sick and the wildness that had been in me all along, that I tried to tamp down with chores and with promises that once I reached college I would be able to do whatever I pleased, burst out. I couldn’t help it. I tried to keep it down but it just flooded through all my quiet spaces. It was a message more than a feeling, a message that tolled like a bell; change, change, change.

It didn’t happen overnight. Yes, the wildness was in me, yes it kept my heart beating fast all the long day, yes it danced around me while I walked down the street, yet it let me look boys straight in the face when they stared at me, yes it turned my laugh from a cough into a long wild fever, but I was still scared.