Harry Tuttle
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Witnessing Violence Can Trigger Violent Behavior
Teens exposed to gun violence more likely to commit violence themselves, researcher claims.
By Serena Gordon
HealthDay Reporter
http://www.healthcentral.com/newsdetail/408/525957.html
THURSDAY, May 26 (HealthDay News) -- Can exposure to gun violence make you more likely to participate in violence?
The answer is yes, according to new research that found teens who had witnessed gun violence or been victims of it were twice as likely to then commit violence.
"This study makes us more confident that there is a substantial cause-and-effect relationship between being exposed to violence and perpetrating violence," said study author Jeffrey Bingenheimer, a doctoral candidate at the University of Michigan in Ann Arbor. "Violence can be socially transmitted from person to person in a community through exposure."
The study, published in the May 27 issue of Science, is believed to be the first one to show a cause-and-effect relationship between exposure to violence and committing violence.
To reach that conclusion, Bingenheimer and his colleagues analyzed data from the large, longitudinal Chicago Neighborhoods study, which includes about 6,000 children from 78 different Chicago neighborhoods.
The researchers began with a group of about 1,500 children who were either 12 or 15 at the start of the study. The researchers took a comprehensive assessment of family history, home and community environment, health, social support, peer influences, school proficiency, previous exposure to violence and more. Both the adolescents and their primary caregiver -- usually their mother -- provided information for the initial assessment.
A second assessment, which took place about two years later, included 1,239 youngsters from the original group. Study volunteers were asked about their exposure to gun violence: 942 said they hadn't been exposed to gun violence; 283 said they had.
There were many differences between the exposed and unexposed groups, according to the study. Teens exposed to gun violence were more likely to be male, from single-parent households, nonwhite and to be on public assistance. According to the researchers, those teens were also more likely to use drugs or alcohol, to be truant from school, to commit property crimes, to have family members with criminal problems and to have witnessed domestic violence in their homes.
The third and final assessment took place almost three years after the second, and the researchers were able to get 984 of the original study volunteers to participate.
They found that most -- 856 -- hadn't become perpetrators of violent crime. But, 122 (12 percent) had become perpetrators. That meant they had carried a hidden weapon, attacked someone with a weapon, shot at someone, or been in a gang fight.
Before controlling for background characteristics, the researchers found a fourfold increase in the chance that someone exposed to violence would become violent themselves.
But, the researchers wanted to control for background factors, such as home and community environment, to see if there truly was a cause-and-effect relationship between exposure to violence and committing violent acts.
Using a special statistical technique called propensity stratification, the researchers used the information on more than 150 characteristics gathered in the first assessment to determine the probability of gun violence exposure, which allowed them to compare those with a high probability of exposure to those who were actually exposed.
After adjusting for these factors, the researchers found that those actually exposed to gun violence were two times more likely to become perpetrators of violence.
While this study wasn't designed to look at the reasons why someone exposed to violence might later become violent in turn, Bingenheimer said that those who have been exposed to violence may be more likely to assume that someone is going to hostile, which "may lead to more preemptive aggressive behaviors."
"When individuals have such traumatic experiences -- witnessing or being exposed to gun violence -- it makes you hypervigilant," added Daniel W. Webster, co-director of the Center for Gun Policy and Research at the Johns Hopkins Bloomberg School of Public Health in Baltimore.
"There are often social stimuli that are ambiguous -- like at a crowded party, someone bumps into you. How do you interpret those stimuli? Most people think, 'It's crowded, it was an accident.' But, youth [who have been exposed to violence] may immediately assume a hostile intent and think someone is trying to challenge them, which can lead to violence, including gun violence," Webster said.
"Guns add a unique dimension to violence, because it's difficult to defend oneself against a gun," Webster added. "Young people, perhaps rightly, perceive that guns are ubiquitous in our society and there's this constant risk of being shot. That has enormous psychological costs."
The study, he said, points to the need for mental health services for those who witness gun violence, as well as additional social support services to help counteract chaotic family lives and problems in school.
More information
To learn more about risk factors for youth violence, as well as protective factors, go to the National Center for Injury Prevention and Control (www.cdc.gov ).
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
May 26, 2005
Exposure to Gun Violence Increases Teen Violence
http://crime.about.com/b/a/172878.htm
Exposure to gun violence makes adolescents twice as likely to perpetrate serious violence in the next two years, according to a University of Michigan study. Researchers found there is a substantial cause and effect relationship between exposure and perpetration of violence.
Jeffrey B. Bingenheimer, a doctoral student in health behavior and health education, analyzed five years of data from adolescents living in 78 neighborhoods in Chicago. Bingenheimer is lead author on a paper in this week's journal Science.
Using a statistical method called propensity stratification, Bingenheimer and coauthors Robert Brennan and Felton Earls aimed to establish a firm cause and effect relationship between exposure to gun violence and later perpetrating violence.
"We wanted to know whether these just tend to occur in the same populations or if one actually caused the other," Bingenheimer said. "These findings suggest there is a substantial cause and effect relationship between exposure and perpetration. Violence can be transmitted from person to person by means of exposure in the community."
Bingenheimer used data from the Project on Human Development in Chicago Neighborhoods, a longitudinal study that conducted extensive interviews with more than 6,000 young people and their primary care givers on everything from reading proficiency to family members with legal problems to delinquency in their peer groups. Bingenheimer used data from about 1,500 adolescents who were within six months of their 12th or 15th birthday at the time of their first interview.
The project is based at Harvard University, with involvement from Columbia University, Emory University, Johns Hopkins, and Pennsylvania State University, among others. Brennan and Earls are faculty members at Harvard.
Propensity Stratification
Bingenheimer said many researchers have looked at how violence begets violence. His use of the complex statistical approaches he learned from Raudenbush help make this paper unique.
While many investigations, such as clinical trials of new drugs, use randomized experiments to test effects, that is not possible in a real-life situation like examining the effects of gun violence. So instead they looked at information provided in questionnaires and used propensity stratification to simulate randomization as best they could.
Overall, Bingenheimer found that adolescents who were exposed to firearm violence were nearly four times as likely as unexposed adolescents to perpetrate violence over the next two years.
Elevated Rates of Violence
But exposed and unexposed adolescents differed on a wide range of demographic, socioeconomic, temperamental and other factors. These differences, rather than gun violence exposure itself, could account for the elevated rates of violence among exposed adolescents. Propensity stratification allowed Bingenheimer to control for the effects of more than 150 characteristics of the adolescents, their families and their neighborhoods.
Propensity stratification combines these variables into a single number, the predicted probability of being exposed to gun violence. If the association between actual exposure and perpetration persists among adolescents who had similar predicted probabilities of exposure, this is evidence of a cause and effect relationship, Bingenheimer said.
The study defined exposure to firearm violence as having been shot or shot at or seeing someone shot or shot at. It defined perpetrating violence as carrying a hidden weapon, attacking someone with a weapon, shooting someone, shooting at someone, or being in a gang fight.
Source: University of Michigan
>>>>
http://www.eurekalert.org/pub_releases/2005-05/uom-etg052505.php
Teens exposed to gun violence more likely to commit violence themselves, researcher claims.
By Serena Gordon
HealthDay Reporter
http://www.healthcentral.com/newsdetail/408/525957.html
THURSDAY, May 26 (HealthDay News) -- Can exposure to gun violence make you more likely to participate in violence?
The answer is yes, according to new research that found teens who had witnessed gun violence or been victims of it were twice as likely to then commit violence.
"This study makes us more confident that there is a substantial cause-and-effect relationship between being exposed to violence and perpetrating violence," said study author Jeffrey Bingenheimer, a doctoral candidate at the University of Michigan in Ann Arbor. "Violence can be socially transmitted from person to person in a community through exposure."
The study, published in the May 27 issue of Science, is believed to be the first one to show a cause-and-effect relationship between exposure to violence and committing violence.
To reach that conclusion, Bingenheimer and his colleagues analyzed data from the large, longitudinal Chicago Neighborhoods study, which includes about 6,000 children from 78 different Chicago neighborhoods.
The researchers began with a group of about 1,500 children who were either 12 or 15 at the start of the study. The researchers took a comprehensive assessment of family history, home and community environment, health, social support, peer influences, school proficiency, previous exposure to violence and more. Both the adolescents and their primary caregiver -- usually their mother -- provided information for the initial assessment.
A second assessment, which took place about two years later, included 1,239 youngsters from the original group. Study volunteers were asked about their exposure to gun violence: 942 said they hadn't been exposed to gun violence; 283 said they had.
There were many differences between the exposed and unexposed groups, according to the study. Teens exposed to gun violence were more likely to be male, from single-parent households, nonwhite and to be on public assistance. According to the researchers, those teens were also more likely to use drugs or alcohol, to be truant from school, to commit property crimes, to have family members with criminal problems and to have witnessed domestic violence in their homes.
The third and final assessment took place almost three years after the second, and the researchers were able to get 984 of the original study volunteers to participate.
They found that most -- 856 -- hadn't become perpetrators of violent crime. But, 122 (12 percent) had become perpetrators. That meant they had carried a hidden weapon, attacked someone with a weapon, shot at someone, or been in a gang fight.
Before controlling for background characteristics, the researchers found a fourfold increase in the chance that someone exposed to violence would become violent themselves.
But, the researchers wanted to control for background factors, such as home and community environment, to see if there truly was a cause-and-effect relationship between exposure to violence and committing violent acts.
Using a special statistical technique called propensity stratification, the researchers used the information on more than 150 characteristics gathered in the first assessment to determine the probability of gun violence exposure, which allowed them to compare those with a high probability of exposure to those who were actually exposed.
After adjusting for these factors, the researchers found that those actually exposed to gun violence were two times more likely to become perpetrators of violence.
While this study wasn't designed to look at the reasons why someone exposed to violence might later become violent in turn, Bingenheimer said that those who have been exposed to violence may be more likely to assume that someone is going to hostile, which "may lead to more preemptive aggressive behaviors."
"When individuals have such traumatic experiences -- witnessing or being exposed to gun violence -- it makes you hypervigilant," added Daniel W. Webster, co-director of the Center for Gun Policy and Research at the Johns Hopkins Bloomberg School of Public Health in Baltimore.
"There are often social stimuli that are ambiguous -- like at a crowded party, someone bumps into you. How do you interpret those stimuli? Most people think, 'It's crowded, it was an accident.' But, youth [who have been exposed to violence] may immediately assume a hostile intent and think someone is trying to challenge them, which can lead to violence, including gun violence," Webster said.
"Guns add a unique dimension to violence, because it's difficult to defend oneself against a gun," Webster added. "Young people, perhaps rightly, perceive that guns are ubiquitous in our society and there's this constant risk of being shot. That has enormous psychological costs."
The study, he said, points to the need for mental health services for those who witness gun violence, as well as additional social support services to help counteract chaotic family lives and problems in school.
More information
To learn more about risk factors for youth violence, as well as protective factors, go to the National Center for Injury Prevention and Control (www.cdc.gov ).
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
May 26, 2005
Exposure to Gun Violence Increases Teen Violence
http://crime.about.com/b/a/172878.htm
Exposure to gun violence makes adolescents twice as likely to perpetrate serious violence in the next two years, according to a University of Michigan study. Researchers found there is a substantial cause and effect relationship between exposure and perpetration of violence.
Jeffrey B. Bingenheimer, a doctoral student in health behavior and health education, analyzed five years of data from adolescents living in 78 neighborhoods in Chicago. Bingenheimer is lead author on a paper in this week's journal Science.
Using a statistical method called propensity stratification, Bingenheimer and coauthors Robert Brennan and Felton Earls aimed to establish a firm cause and effect relationship between exposure to gun violence and later perpetrating violence.
"We wanted to know whether these just tend to occur in the same populations or if one actually caused the other," Bingenheimer said. "These findings suggest there is a substantial cause and effect relationship between exposure and perpetration. Violence can be transmitted from person to person by means of exposure in the community."
Bingenheimer used data from the Project on Human Development in Chicago Neighborhoods, a longitudinal study that conducted extensive interviews with more than 6,000 young people and their primary care givers on everything from reading proficiency to family members with legal problems to delinquency in their peer groups. Bingenheimer used data from about 1,500 adolescents who were within six months of their 12th or 15th birthday at the time of their first interview.
The project is based at Harvard University, with involvement from Columbia University, Emory University, Johns Hopkins, and Pennsylvania State University, among others. Brennan and Earls are faculty members at Harvard.
Propensity Stratification
Bingenheimer said many researchers have looked at how violence begets violence. His use of the complex statistical approaches he learned from Raudenbush help make this paper unique.
While many investigations, such as clinical trials of new drugs, use randomized experiments to test effects, that is not possible in a real-life situation like examining the effects of gun violence. So instead they looked at information provided in questionnaires and used propensity stratification to simulate randomization as best they could.
Overall, Bingenheimer found that adolescents who were exposed to firearm violence were nearly four times as likely as unexposed adolescents to perpetrate violence over the next two years.
Elevated Rates of Violence
But exposed and unexposed adolescents differed on a wide range of demographic, socioeconomic, temperamental and other factors. These differences, rather than gun violence exposure itself, could account for the elevated rates of violence among exposed adolescents. Propensity stratification allowed Bingenheimer to control for the effects of more than 150 characteristics of the adolescents, their families and their neighborhoods.
Propensity stratification combines these variables into a single number, the predicted probability of being exposed to gun violence. If the association between actual exposure and perpetration persists among adolescents who had similar predicted probabilities of exposure, this is evidence of a cause and effect relationship, Bingenheimer said.
The study defined exposure to firearm violence as having been shot or shot at or seeing someone shot or shot at. It defined perpetrating violence as carrying a hidden weapon, attacking someone with a weapon, shooting someone, shooting at someone, or being in a gang fight.
Source: University of Michigan
>>>>
http://www.eurekalert.org/pub_releases/2005-05/uom-etg052505.php
