D: Kids often get infected with contagious diseases by other kids.
Y: But the spread of an infection is not necessarily limited to illnesses such as colds and flu. According to researchers at The Ohio State University, adolescents can also spread violence among their social networks.
D: The researchers looked at data from nearly 6,000 young people who were interviewed as part of the National Longitudinal Study of Adolescent Health. Among other questions, the participants were asked how many times in the past year they had been in a serious physical fight, how frequently they had seriously wounded another person, and how often they'd pulled a weapon on someone.
Y: The results showed that this type of violent behavior is contagious. For example, study participants were 48 percent more likely to have had a serious fight if a friend had done the same. And they were 183 percent more likely to have seriously hurt someone if a friend had hurt someone. Adolescents were also 140 percent more likely to have pulled a weapon on someone if a friend had also pulled a weapon.
D: In fact, the contagion of violence spread not only to friends but also to friends of friends, up to four degrees of separation.
Y: The phenomenon is not entirely surprising. People with similar interests and proclivities tend to socialize and become friends--a phenomenon known as the "clustering effect."D: This matters because if friends influence each other to be violent, they can potentially also influence each other to be less violent. So programs aimed at reducing violence among adolescents could have a beneficial ripple effect.