Is anyone here familiar with the Ophelia Project? It deals with the subject being discussed in this thread - Relational Agression.
http://www.opheliaproject.org/issues/issues_RA.shtml
From the website:
"Aggression" is defined as behavior that is intended to harm others. Aggression can take many forms, but physical forms of aggression (getting into physical fights, dating violence, violent crimes) have received the most attention from researchers, educators, and parents, who understandably are interested in protecting their children from the serious harm that physical aggression often inflicts. Because most females of all ages (with the exception of toddlers) engage in comparatively low levels of physical aggression, this focus on physical aggression has lead to the notion that females are "less aggressive" than males.
What we now know is that school-aged girls are far more aggressive than has been previously believed; their preferred expression of aggression, however, is not physical, but relational aggression.
Relational aggression encompasses behaviors that harm others by damaging (or threatening to damage) or manipulating one's relationships with his/her peers, or by injuring one's feelings of social acceptance. For example:
Purposefully ignoring someone when angry (giving the "silent treatment")
Spreading rumors about a disliked classmate
Telling others not to play with a certain classmate as a means of retaliation.
In each of these examples, social relationships are used as the vehicle for harming a peer.
How Girls Hurt Each Other: One Example
A high school student, one of 12 who had met to talk to us at an advisory council meeting, told us this story. She cried as she recounted being tormented in middle school by her classmates. For some reason she was targeted as a "dog," and day after day she had to walk the halls with kids barking at her. There was silence in the room as we each imagined the horror of that kind of rejection. Finally we asked her, "Then what happened? How did it stop?" She replied softly, "I stopped it." We breathed a sigh of relief. Great! Thank goodness. "How?" we asked. Her voice was so quiet we had to strain to hear her. "I picked out another girl, someone worse off than me, and started to call her a dog. Then the others forgot about me. We barked at her instead."