One of the interesting differences between boy and girl bullying is that many girl bullies bully in groups. There may be a “head” bully that orchestrates or starts the bullying, but her social circle is right there behind her backing her up. Girl bullies seem to feel braver and safer bullying from within the confines of their tight-knit social group.
A common method of girl bullying is exclusion and social isolation. These techniques require a group of “insiders” in order to be successful forcing someone into the “outsider” position. There must be an “us” and a “them” or a “we” and a “you” for rejection and shunning to be carried out effectively.
In Rachel Simmons's book Odd Girl Out: The Hidden Culture of Aggression in Girls, Simmons says, “When the politics of popularity devastate girls' relationships, the loss is multi-layered. A girl is abandoned by someone she loves and trusts. The loss signals her low social value, an event that shrinks her self-esteem and for which she blames herself. She learns a new, dark understanding of relationship as a tool. And where the abandonment is public and followed by cruelty, there is public scorn and shame.”
The book Best Friends, Worst Enemies: Understanding the Social Lives of Children by Michael Thompson, Lawrence J. Cohen, and Catherine O'Neill Grace not only describes the social lives of kids, but the appropriate roles of parents, teachers, and school administrators.
This quote sums up the feeling of rejection and hurt a girl feels when a group of girls turn on her and excludes her from their tight-knit circle. The victim becomes an instant outsider and the group has the shared goal of keeping her out. The girls within the group are scared; they see what the bullied girl is going through and worry that someday it will be them.
In order to prevent that from happening, even normally nice girls will behave in cold, cruel ways. The fear is often so strong; girls will actually admit that they are glad that someone else is being targeted because as long as another girl is being bullied, they are safe.