Teen Brain Development: Neural Gawkiness

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chris sturgisThe young are heated by Nature as drunken men by wine.   -- Artistotle

Adults' enduring perplexity about teenagers are captured in quotes by Aristotle and Shakespeare in The New Science of the Teenage Brain, the cover story of the October National Geographic Magazine. The article, by David Dobbs, explains how young people's lives are shaped by the mind-blowing reorganization occurring in the brains of adolescents between the ages of 12-25. The article is fascinating, and it's worth reading the entire piece. It's also a fabulous tool for us to use to get policymakers' attention as to why so many policies and programs like Scared Straight, lock them up, and zero tolerance don't work. So after reading the article, spend a few minutes sending an email or two or a letter to the editor of your local paper.

According to Dobbs, scientists started to look at what was happening in young people's brains in the 1990's. He explains what the scans showed:

...our brains undergo a massive reorganization between our 12th and 25th years. The brain doesn't actually grow very much during this period. It has already reached 90 percent of its full size by the time a person is six, and a thickening skull accounts for most head growth afterward. But as we move through adolescence, the brain undergoes extensive remodeling, resembling a network and wiring upgrade.

For starters, the brain's axons—the long nerve fibers that neurons use to send signals to other neurons—become gradually more insulated with a fatty substance called myelin (the brain's white matter), eventually boosting the axons' transmission speed up to a hundred times. Meanwhile, dendrites, the branchlike extensions that neurons use to receive signals from nearby axons, grow twiggier, and the most heavily used synapses—the little chemical junctures across which axons and dendrites pass notes—grow richer and stronger. At the same time, synapses that see little use begin to wither. This synaptic pruning, as it is called, causes the brain's cortex—the outer layer of gray matter where we do much of our conscious and complicated thinking—to become thinner but more efficient. Taken together, these changes make the entire brain a much faster and more sophisticated organ.

The changes move from the back to the front of the brain as the young adult brain is formed. Dobbs explains:

The corpus callosum, which connects the brain's left and right hemispheres and carries traffic essential to many advanced brain functions, steadily thickens. Stronger links also develop between the hippocampus, a sort of memory directory, and frontal areas that set goals and weigh different agendas; as a result, we get better at integrating memory and experience into our decisions. At the same time, the frontal areas develop greater speed and richer connections, allowing us to generate and weigh far more variables and agendas than before.

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.

That's the important point. The brain is tripping over itself.

The article is fascinating as it moves us from focusing on what adults see as problems -- teens' lack of impulse control or inconsistent behavior -- to an understanding of the adaptive qualities of adolescent behavior. The attention to peers, thrill-seeking, and risk-taking contribute to youth making the transition to adulthood. It gets them " ut of the house and into new turf."

If we understand the high premium the teenage brain places on rewards and social connections, we start to have a different way of thinking about how social-emotional issues impact engagement and achievement in school.  Social-emotional issues can't be relegated to after school programming or a life skills course. Dobbs explains, "This supremely human characteristic makes peer relations not a sideshow but the main show."

The last section of the article was tear-spilling inspiration for me. Dobbs explains that the "prolonged plasticity" of the frontal areas of the brains produces flexibility. As teens have new experiences, their brains will develop and respond in response. This is scientific evidence for what youth development practitioners have always known: It's never to late too help a young person.

This post originally appeared on the Connected by 25 blog, published by the Youth Transition Funders Group. It is reprinted with permission from Reclaiming Futures, a national initiative working to improve alcohol and drug treatment outcomes for youth in the juvenile justice system.

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