The Teen Brain on Rage: How It's Different

An immature brain may play a role in making teens like the 17-year-old Ohio shooting suspect more prone to violence.

When does a person really become a "grown up"? Laci Green looks at how the brain matures and what it means -- from a scientific perspective -- to be an adult.

The Gist:

- The 17-year-old suspect in the school shootings in Ohio has been described as a loner from a troubled home.

- During adolescence, the brain is in a stage of adaptation

- This makes it challenging for teens to make good decisions in the heat of the moment.

In the weeks and months following a tragedy like this week's school shooting in Ohio, experts and lawyers and school psychologists and classmates will try to make sense of the actions of the 17-year-old suspect.

In all likelihood, though, no one will ever be able to pinpoint a single reason, said pyschologist David Walsh, author of "Why Do They Act That Way? A Survival Guide to the Adolescent Brain for You and Your Teen."

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"There are usually multiple factors that take a long time to sort out," Walsh said. "It's irrational, so looking for a reason can be somewhat frustrating. There are many kids who probably share that profile who don't do anything remotely like what he did.

Science, however, can shed some light on how he and other teenagers think.

"Adolescents can make good decisions," insists B. J. Casey, a neuroscientist at Weill Cornell Medical College. "They can make better decisions than you or I. But it is in the heat of the moment that they get into trouble."

That's because the reward-sensitive areas of the brain are maturing with the onset of puberty. There's been a long-held view that teens make poor decisions because they don't think through consequences. Since the 1990s, we've known that brains go through extensive development in adolescence.

Myelin, or white matter, provides more insulation and boosts the ability of the axons to send signals faster. New connections are being made in the frontal cortex and older ones are dying.

But new research shows that understanding the consequences of decisions isn't exactly the problem: In emotionally neutral situations, teenagers take risks similarly to adults. And if it were simply the matter of an immature brain, children would make worse decisions than teens, Casey said. But they don't.

What throws teens off is the reward for taking a risk. And since teens are so tuned into their peers, showing off for friends is perceived as a huge reward.

"Basically, they can make pretty good judgments and decisions in cold situations that don't involve emotions or rewards, but in the heat of the moment their decisions tend to fall apart," Casey said.

Take the research of Laurence Steinberg, a professor of developmental psychology at Temple University: When he watched teens and adults play a video game in which you try to drive from one end of town to the other as quickly as possible, he noticed the teens chanced running red lights at about the same rate that adults did.

But when he brought the teenager's friends into the room to watch, the teens tried to gun it through the lights -- taking twice as many risks as they did in an empty room. The adults drove the same with onlookers.

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"It is very difficult for a 16-year-old to resist peer pressure in a heated, volatile situation," Steinberg said in a press release after one of his studies. "Most times, there is no time to talk to an adult to inject some reason and reality to the situation. Many crimes committed by adolescents are done in groups with other teens and are not premeditated."

Another study showed that teens use different areas of their brains to perceive emotion.

When scientists at the McLean Hospital in Belmont, Mass., showed a group of teenagers and a group of adults pictures of faces, the adults correctly identified the emotion in the pictures as fear.

The teens' answers varied...and, because the scientists were watching the brain activity of the subjects through functional magnetic resonance imaging, the researchers could tell the teens were using the amygdala, a small region of the brain that's known for gut reactions, whereas the adults used the frontal cortex.

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