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Vendaval -> CNN: Teen brain key to understanding criminal behavior (12/28/2007 7:22:31 PM)
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From CNN.com/health
Friday, December 28, 2007
Expert: Teen brain key to understanding criminal behavior
" Violence toward others also tends to peak in adolescent years, says psychiatrist Dr. Peter Ash of Emory University. It's mostly likely to start around age 16, and people who haven't committed a violent crime by age 19 only rarely start doing it later, he said.
The good news here, he said, is that a violent adolescent doesn't necessarily become a violent adult. Some two-thirds to three-quarters of violent youth grow out of it, he said. "They get more self-controlled."
Some of the changes found in behavioral studies are paralleled by changes in the brain itself as youths become adults.
In fact, in just the past few years, Steinberg said, brain scans have given biological backing to commonsense notions about teen behavior, like their impulsiveness and vulnerability to peer pressure.
It's one thing to say teens don't control their impulses as well as adults, but another to show that they can't, he said. As for peer pressure, the new brain research "gives credence to the idea that this isn't a choice that kids are making to give in to their friends, that biologically, they're more vulnerable to that," he said.
Consider the lobes at the front of the brain. The nerve circuitry here ties together inputs from other parts of the brain, said Dr. Jay Giedd of the National Institute of Mental Health.
This circuitry weighs how much priority to give incoming messages like "Do this now" versus "Wait! What about the consequences?" In short, the frontal lobes are key for making good decisions and controlling impulses.
Brain scans show that the frontal lobes don't mature until age 25, and their connections to other parts of the brain continue to improve to at least that age, Giedd said.
The inexplicable behavior and poor judgments teens are known for almost always happen when teens are feeling high emotion or intense peer pressure, conditions that overwhelm the still-maturing circuitry in the front part of brain, Giedd said.
As Steinberg sees it, a teenager's brain has a well-developed accelerator but only a partly developed brake.
By around 15 or 16, the parts of the brain that arouse a teen emotionally and make him pay attention to peer pressure and the rewards of action -- the gas pedal -- are probably all set. But the parts related to controlling impulses, long-term thinking, resistance to peer pressure and planning -- the brake, mostly in the frontal lobes -- are still developing.
"It's not like we go from becoming all accelerator to all brake," Steinberg said. "It's that we go from being heavy-foot-on-the-accelerator to being better able to manage the whole car."
Giedd emphasized that scientists can't yet scan an individual's brain and draw conclusions about how mature he is, or his degree of responsibility for his actions.
Brain scans do show group differences between adult and teen brains, he said, "but whether or not that should matter (in the courtroom) is the part that needs to be decided more by the judicial system than the neuroscientist." "
(read the rest of the article by clicking on the link below)
http://www.cnn.com/2007/HEALTH/12/28/teen.brain.ap/index.html
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