The science of violence: As the toll of teen violence grows, scientists search for reasons why - Life Science: Teen Health The Brain Hormones - research - Statistical Data Included

Science World, Oct 15, 2001 by Pearl Gaskins

A 17-year-old is shot and killed after an argument with a group of teens. A 16-year-old gang member slays a police officer. These two violent tales made headlines in America's heartland, Chicago, a steamy week last July. But they could--and have--happened anywhere in the U.S.

Teen violence has especially grabbed the spotlight since 18-year-old Eric Harris and 17-year-old Dylan Klebold launched an assault inside Columbine High School in Littleton, Colo., on April 20, 1999. They shot and killed 13 people and injured more than 20 before taking their own lives--the worst incident of school gun violence in U.S. history.

Since 1994, the number of teens arrested for serious violent crimes--murder, robbery, and rape--has plummeted from more than 500 arrests per 100,000 teens in 1994 to fewer than 350 arrests per 100,000 in 1999. Still, more than 100,000 teens under 18 were arrested for violent crimes in i999, and teen violence in schools has actually increased.

Now scientists are searching for the roots of violent behavior. You'll read some findings on the following pages. But first read each statement below and decide whether it's true or false. Then turn the page to learn more about youth violence.

QUIZ: MYTHS AND FACTS

1. Scientists think some people are born violent--they inherit a "violence" gene.

True False Maybe

2. Exposure to violence in the media (TV, movies, video games, music lyrics, the Internet) causes people to become violent in real life.

True False Maybe

3. Drug and alcohol use is linked with violence.

True False Maybe

4. Children who experience physical abuse are more likely to become violent themselves.

True False Maybe

5. Hormones, puberty, and other developmental factors increase teen violence.

True False Maybe

Answers

1. False. "There is no gene that is a `violence' gene," says Delbert Elliott, director of the Center for the Study and Prevention of Violence at the University of Colorado in Boulder. But that doesn't mean genes (hereditary material in cells) don't play any role in violent behavior. Says Elliott: Scientists just don't yet understand that role.

For example, research suggests people may inherit certain broad personality traits, like impulsivity, the tendency to act or react immediately without mental reflection. A genetic trait like impulsivity combined with environmental risk factors--exposure to street violence or peer pressure from gangs, for example--might increase the chance of someone becoming violent. "But violent behavior is the result of a combination of factors, not any one alone," Elliott says.

2. True. Before American teens turn 18, they've witnessed an estimated 200,000 acts of violence on TV. Evidence suggests exposure to violence in the media can trigger short-term aggressive behavior--behavior intended to harm others, including shoving and starting fights. That aggression usually lasts a few hours or days. Evidence that exposure to media violence causes aggressive teens to rob or murder is far weaker, claims "Youth Violence: A Report of the Surgeon General," published earlier this year.

However, many experts think media violence does exert a lasting impact. Leonard Eron, senior scientist at the University of Michigan's Institute for Social Research, has tracked 856 people since they were 8 years old. He gathered data about their aggression levels as rated by their peers, and the amount and types of TV programs they watched when they were 8, 10, 19, and 30: "We found evidence at each stage that the more violence they watched as children, the more aggressive they were." This includes using abusive language and developing antisocial attitudes.

What about exposure to violence in music lyrics, video games, and on the Internet? Some researchers think violent video games actually teach aggressive behavior because players participate in the violence--think of any game that asks players to "kill" human-looking targets, for example. But far more research on media-linked violence is needed before conclusions can be drawn.

3. True. "Those people who are violent often use drugs, and those people who use drugs are often violent," says Elliott. In a study of 7- to 15-year-old offenders who committed serious violent crimes in Denver, Colorado, about 58 percent regularly used alcohol and 34 percent regularly used marijuana--rates higher than those of non-violent youth. But, cautions Elliott, substance abuse itself doesn't cause violent behavior. In most cases, he says, people already exhibit violent behavior before they ever touch drugs: "The factors in one's background and personality that lead to violence--like impulsivity and antisocial attitudes--are the same things that lead to drug use."

4. Maybe.

Researches disagree on the issue of physical abuse as a violence-causing factor. Physically abused children can suffer from depression and other serious mental health problems, says Elliott. But they're only slightly more likely to become violent than their non-abused peers. "Exposure to violence at home can produce two outcomes," he says. "It can produce an outcome of, `Ah, that's an effective way of getting something I want and I'll use that.' Or else: `I remember what that was like and I'm never going to do that to someone else.'"