学校为人们提供了更多的教育机会，他们为青年人也为社会之间的互动提供了更多的机会。同时，这些社会机会也为孩子们提供了更多额机会，从而产生了各种的欺负行为的现象。在过去的十年中，在美国关于对欺负行为的研究有戏剧性的增长。这个研究主要是针对校园被欺负的受害者一直受到学校暴力犯罪者的持续极端暴力的现象进行研究。

欺负行为包括一系列各种的攻击性行为，其目标是针对一个特定的受害者。这种行为和打架不一样，因为它涉及的是一个能力的不平衡，如被目标确定的个人很难定义他还是她。欺负行为已经成了现在儿童的一个普遍的共同的障碍。许多人认为欺凌是自然成长过程中的一部分，它不但不会对儿童造成严重伤害，而且还有助于让孩子在困难中成长。而在另一方面，通过在这领域的广泛研究，专家们已经鉴定了欺负行为可能对受害者产生的后果。

Schools offer more than educational opportunities; they offer many opportunities for social interaction for youth. These social opportunities also offer many opportunities for children to become victims of bullying. In the last ten years, there has been a dramatic rise of research on bullying in the United States. This research has been spurred by continued extreme school violence where the perpetrators of the violence had been victims of bullying.

Bullying encompasses a range of various aggressive behaviors, which are targeted at an identified victim (Espalage, 2002). It is differentiated from fighting because it involves an imbalance in strength such that the individual targeted has difficulty defending him or herself. Bullying has been a common obstacle of childhood for many generations (Olweus, 1995). Many people believe that bullying is a natural part of growing up that does not cause serious harm but help to toughen children up (Pianta & Walsh, 1995). On the other hand, extensive research in this area has identified consequences for the victims of bulling (Olweus, 1995).

There have been many high profile cases of victims of bullying who have retaliated by horrific school shootings (Kumpulamen, Rasanen, & Puura, 2001). A number of recent studies have investigated the immediate and short-term effects of peer victimization (Espelage, 2002; Espelage & Swearer, 2003; Nansel, Overpeck, Pilla, Ruan, Simons-Morton, & Scheidt, 2001).
Rejection from a peer group has been linked to adverse psychological and physical consequences (Kumpulamen et al., 2001). Victims have been noted to be at risk for increased levels of depression, anxiety, and psychosomatic symptoms (Nansel et al., 2001). School avoidance and feelings of isolation are common among victims. Furthermore, it has been reported that these victims of bullying are developing post-traumatic stress disorder (Kumpulamen et al., 2001). This reveals the detrimental impact that peer rejection may have on youth and the importance of more research on the long-term impact bullying has on victims.

The media has portrayed “bullies” and “nerds or geeks” in numerous films, thus bringing awareness of childhood social hierarchies and the desire to be accepted as part of a group. The “nerds” are social outcast who are commonly victimized by their peers and often blamed for not being tough enough. Recent research and pop culture movies like “Mean Girls” have brought more attention to girls and their bullying behaviors. There is limited research on the prevalence and effects bullying has on girls (Brinson, 2005).

Many bullies experience mental health difficulties. One study found that one-third of bullies have attention-deficit disorder, 12.5% were suffering from depression, and 12.5% had oppositional-conduct disorder (Kumpulamen et al., 2001). Bullies then in turn take out their frustrations on someone the see as weaker than them. These bullies are also seeking to impress their peers. The rejection felt by the victim can have a direct impact on their lives.

Several authors suggest that youth who are continually victimized may be at risk for poorer psychological functioning as adults (Espelage, 2002; Nansel et al., 2001). There has not been much research in this particular area. Little is known about how these victims function as adults. Research suggest that adolescents do not simply grow out of emotional problems with age, which implies that youth who have poor social skills may continue to experience difficulty in their area of maintaining relationships as adults (Nansel et al., 2001). Espelage (2002) found that many victims of bullying continue to think about their experiences of being bullied and recall painful memories well into adulthood.

Depression and suicidal ideation have been found to be common outcomes of being bullied for both boys and girls. Bullies themselves have been prone to depression (Espelage, 2002). Bullying behaviors has similarly been found to transfer from the classroom to the streets, male bullies having been found to be seventeen times more likely to be frequently violent outside of the classroom and female bullies over one hundred times more likely to be frequently violent on the streets (Brinson, 2005). Longitudinal research has found that bullying and aggressive behavior were identified as being characteristics of those students who later became involved in criminal behavior (Nansel et al., 2001).