https://www.sciencedaily.com/releases/2021/02/210217151139.htm

"To the extent that this is true, we should expect them to target not vulnerable wallflowers, but their own friends, and friends-of-friends, who are more likely to be their rivals for higher rungs on the social ladder," said Robert Faris, a UC Davis researcher on bullying and author of the paper "With Friends Like These: Aggression From Amity and Equivalence." The paper was published recently in the American Journal of Sociology. Co-authors are sociologists Diane Felmlee at Pennsylvania State University and Cassie McMillan at Northeastern University.

Faris, a professor of sociology, said friends and associates with close ties to one another likely compete for positions within the same clubs, classrooms, sports and dating subgroups, which heightens the risk of conflict and aggression. This paper is the first known to show that those rivals are often their own friends.