Study: Immaturity may spark teen crime

Study: Immaturity may spark teen crime

By MALCOLM RITTER, AP Science Writer
Sun Dec 2, 2007 12:24 PM ET

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 psychology 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 is often cited as state lawmakers consider scaling back
punitive juvenile justice laws passed during the 1990s.

"As any parent knows," wrote Justice Anthony Kennedy for the 5-4
majority, 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.

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

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



_emotionally volatile.

_likely to take risks.

_reactive to stress.

_vulnerable to peer pressure.

_prone to focus on and overestimate short-term payoffs and underplay longer-term consequences of what they do.

_likely to overlook alternative courses of action.

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

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

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."

Steinberg, who frequently testifies on juvenile justice policy
and consults with state legislators on the topic, said it’s not clear
to him how much the research on teen brains affects lawmakers. They
seem more swayed by pragmatic issues like the cost of treating teens as
adults, he said. But he noted that he has been asked to testify more in
the past few years than before.

In any case, experts say, there’s nothing particularly magic
about the age 18 as a standard dividing line between juveniles and
adults in the courtroom.

Different mental capabilities mature at different rates,
Steinberg notes. Teens as young as 15 or 16 can generally balance
short-term rewards and possible costs as well as adults, but their
ability to consider what might happen later on is still developing, he

A dividing line of age 18 is better than 15 and not necessarily
superior to 19 or 17, but it appears good enough to be justified
scientifically, he said.

Steinberg said he thinks courts should be able to punish some
16- or 17- year olds as adults. That would be reserved for repeat
violent offenders who’ve resisted rehabilitation by the juvenile
justice system, and who could endanger other youth in the juvenile
system if they returned. "I don’t think there are a lot of these kids,"
Steinberg said.

For the rest, he thinks it makes sense to try rehabilitating
young offenders in the juvenile justice system. That’s better than
sending them through the adult system, which can disrupt their
development so severely that "they’re never going be able to be a
productive member of society," Steinberg said. "You’re not doing
society any favor at all."

Ash said that to decide whom to treat as an adult, courts need
some kind of guideline that combines the defendant’s age with the crime
he’s accused of. That should leave room for individual assessments, he

But "we don’t have very good measuring sticks" for important traits like how impulsive a juvenile is, he said.

In any case, the decision for each defendant should balance a
number of reasons for punishment, like retribution, protecting society,
deterring future crime, and rehabilitation, said Ash, who’s a member of
the American Psychiatric Association’s Committee on Judicial Action.

Even if a 14-year-old murderer is held morally responsible for
the crime, he will have matured by the time he’s 18, and in the
meantime he may be more amenable to rehabilitation than an adult
murderer is, Ash said.

In fact, most experts conclude that rehabilitation works better for juveniles than for adult offenders, he said.

And just as parents know how irrational juveniles can be, Ash
said, they also know that rehabilitation is a key goal in punishing

"What we really want," he said, "is to turn delinquent kids into good adults."


On the Net:

American Psychiatric Association statement on youth sentencing:

Psychiatrists’ brief in Supreme Court case:

American Psychological Association brief:


AP National Writer Sharon Cohen contributed to this story.

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