(CBS/AP) When parents ship off to war, their kids back home become more violent - girls as well as boys. That's the apparent message of new research showing that children of parents in the military are more than twice as likely to carry a weapon, join a gang, or be involved in fights.
"This study raises serious concerns about an under-recognized consequence of war," said Sarah Reed, who led the research of military families in Washington state.
Last year, nearly 2 million U.S. children had at least one parent in the military. Deployment can hurt a family in several ways. There's stress while that parent is overseas and in danger, as the remaining parent has to shoulder more responsibility and family roles shift. There can also be challenges after deployed parents return, especially if they were injured physically or psychologically.
The new study is considered the first of its kind to focus on those affected by deployments to Afghanistan and Iraq. It's unique in that it looked at a statewide swath of the population in comparing the behavior of kids in military families to children in non-military families.
The study, to be presented Monday at a public health conference in Washington, D.C., was based on a 2008 questionnaire survey of about 10,000 students in the 8th, 10th and 12th grades in Washington. That state has the sixth-largest active duty population in the nation.
About 550 of surveyed children said they had a parent deployed to a combat zone in the previous six years.
The study tried to account for differences in educational background and other issues between military families and the general population that might skew the results.
Even accounting for such differences, the researchers found that high school-age daughters of deployed parents were almost three times more likely than civilian girls to be in a gang or get into a fight. They were more than twice as likely to carry a weapon to school. There were similar increases among boys of deployed families when compared to civilians.
To be sure, such behavior in boys is more common - the rate of boys from deployed families involved in such violent behaviors was twice as high as for girls in deployed families. But experts say the findings contradict the traditional view that girls under stress exhibit "internalizing" behaviors, like becoming depressed or thinking about suicide, while boys are the ones who "externalize" through violent behavior
The new research may be a wake-up call for health professionals who deal with military families, one expert suggested.
"Maybe if we make assumptions about children, we may overlook other ways they may be suffering," said Dr. Gregory Gorman, an assistant professor of pediatrics at the Uniformed Services University of the Health Sciences in Bethesda, Md.
The National Institute of Mental Health has more on children and violence.