Teens are more likely to be bullied by their friends than classmates they do not know well, according to a new study.

Researchers in the US have been investigating how and why bullying occurs, seeking new information for anti-bullying efforts.

Stats suggest about 20 per cent of students ages 12 to 18 report being bullied at school during the school year. 

“People often assume that bullying occurs between relative strangers, or that it targets those on the fringes of the social network,” researcher Dr Diane Felmlee says. 

“Those do occur, but in our study, we find that the rate of peer aggression is significantly higher between those students who are closely linked. 

“Furthermore, our finding is not due to friends simply spending more time together, nor is it only animosity between former friends. 

“Even those whose friendship continued over the school year were more likely to bully those friends.”

The findings were based on data from more than 3,000 students. The dataset was collected in waves, starting when the students were in grades six, seven and eight and finishing when they were in grades eight, nine and 10, respectively. 

The researchers constructed ‘aggression networks’ by asking students to nominate up to five classmates who had picked on or been mean to them, allowing the researchers to identify both bullies and victims. 

Participants also were asked to identify their friends at each wave, allowing the researchers to track friendships over time. In addition, the researchers measured anxiety, depression and how positively attached the students felt to their school.

Analysing the data, the researchers found that peer aggression occurred at higher rates between friends, and friends-of-friends, than between those not closely tied. 

One of the students who reported being the victim of a friend noted, “Sometimes your own friends bully you. I don't understand why, why my friends do this to me”.

Additionally, participants who were friends in the beginning of the school year were over three times as likely to bully or victimise the other by the end of the same school year. 

Being bullied by a friend was also linked to significant increases in anxiety and depression, and lower levels of school attachment.

The researchers argue that this friend-on-friend bullying can be a deliberate way to try to compete for social status.

“These conflicts likely arise between young people who are eyeing the same spot on the team, club, or vying for the same best friend or romantic partner,” Dr Felmlee said. 

“Those who are closely linked in the school social network are apt to encounter situations in which they are rivals for identical positions and social ties.”

The result could assist not only in improving bullying prevention programs, but also help bullying victims cope by knowing they are not alone.

“Many adolescents may not be aware of how common friend-to-friend bullying is,” Dr Felmlee said. 

“Knowing that they are not alone in such an experience could be reassuring. Plus, a better understanding of the social processes that underlie aggression among ‘frenemies’ could aid parents and school counselors in attempting to help young victims and their bullies.”

The study is accessible here.