Young adults were up to 183 per cent more likely to carry out some acts of violence if one of their friends had also committed the same act, proving that violence spreads like a contagious disease, researchers said.
The study revealed that violence was not just restricted to friends but it extended up to four degrees of separation; meaning from one person to a friend, to the friend's friend and two more friends beyond.
But the researchers noticed that the influence declined with each degree of separation, though was still noticeable.
Robert Bond, Assistant Professor at the Ohio State University in the US and lead author of the findings said that study has showed that violence spread as a contagious disease. He added that acts of violence could ricochet through a community by travelling through networks of friends.
For the study, the team examined responses from 5,913 students in grades 7 to 12 from 142 schools across US.
The results showed that participants in the study were 48 per cent more likely to have been in a serious fight, 183 per cent more likely to have hurt someone badly and 140 per cent more likely to have pulled a weapon on someone if a friend had engaged in the same behaviour.
Violence spreads within social networks just as characteristics and behaviours from happiness to obesity to smoking spreads, the study revealed.
Much of that association is related to what scientists call a "clustering effect" -- people with similar interests, including the use of violence, tend to cluster together as friends.
"If we can stop violence in one person, that spreads to their social network. We're actually preventing violence not only in that person, but potentially for all the people they come in contact with," Bond said.
The results appear online in the American Journal of Public Health.
(With IANS Inputs)