Violence in Youth Begets More Violence

Taking part in or witnessing gun violence in person more than doubles the chances that a teenager will commit a violent or aggressive act within the following two years, new findings published in the 27 May 2005 issue of the journal Science suggest.

Although researchers have found a connection between exposure to violence and violent behavior, they have had difficulty showing that the first causes the second. The gold standard for showing causality is a randomized experiment, in which subjects are randomly assigned to either a group that experiences some sort of "treatment" or a "control" group that does not.

But, this approach wasn't ethically possible for Jeffrey Bingenheimer and colleagues' study of more than 1500 adolescents in Chicago. Instead, the authors used a wide range of information about the adolescents to determine their probability of being exposed to gun violence. Then they compared adolescents who were equally likely to be exposed but whose actual exposure status differed, thus approximating a randomized experiment.

Although it isn't possible to remove all the potential "confounding variables" that might also be contributing to this phenomenon, the data, collected from the adolescents over a five-year period, indicate that being randomly exposed to gun violence significantly increases the likelihood that a teenager will later engage in violence.

Kathy Wren

27 May 2005