Tuesday, Dec. 04, 2007

Teens at the mercy of developing brains

Research explains inability to link actions, consequences

NEW YORK -- The teenage brain, Laurence Steinberg says, is like a car with a good accelerator but a weak brake. With powerful impulses under poor control, the likely result is a crash.

And, perhaps, a crime.

Steinberg, a Temple University psy- chology professor, helped draft an American Psychological Association brief for a 2005 case in which the U.S. Supreme Court outlawed the death penalty for crimes committed before age 18.

That ruling relies on the most recent research on the adolescent brain, which indicates the juvenile brain is still maturing in the teen years, and reasoning and judgment are developing well into the early to mid-20s. It often is cited as state lawmakers consider scaling back punitive juvenile justice laws passed during the 1990s.

"As any parent knows," wrote Associate Justice Anthony Kennedy for the 5-4 major-ity, youths are more likely to show "a lack of maturity and an underdeveloped sense of responsibility" than adults. "... These qualities often result in impetuous and ill- considered actions and decisions."

He also noted that "juveniles are more vulnerable or susceptible to negative influences and outside pressures, including peer pressure," causing them to have less control over their environment.

Some child advocates have pointed to the Supreme Court decision and the research as evidence that teens -- even those accused of serious crimes -- should not be regarded in the same way as adults in the criminal justice system.

Explanation is not absolution

Dr. David Fassler, a psychiatry professor at the University of Vermont College of Medicine who has testified before legislative committees on brain development, says the research doesn't absolve teens but offers some explanation for their behavior.

"It doesn't mean adolescents can't make a rational decision or appreciate the difference between right and wrong," he said. "It does mean, particularly when confronted with stressful or emotional decisions, they are more likely to act impulsively, on instinct, without fully understanding or analyzing the consequences of their actions."

Experts say that even at 16 and 17, when compared with adults, juveniles on average are more:

impulsive

aggressive

emotionally volatile

likely to take risks

reactive to stress

vulnerable to peer pressure

prone to focus on and overestimate short-term payoffs and underplay long-term consequences of what they do

likely to overlook alternative courses of action

Violence toward others tends to peak in adolescence, says psychiatrist Dr. Peter Ash of Emory University. It's mostly likely to start about age 16. People who haven't committed a violent crime by 19 rarely start doing so later, he said.

The good news, he said, is that a violent adolescent doesn't necessarily become a violent adult. 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 the past few years, Steinberg said, brain scans have given biological backing to common sense notions about teen behavior, such as 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.