Although there is still a scientific debate on the nature and definition of bullying, most researchers understand this behavior as aggression characterized by

  1. causing intentional harm
  2. repetition, and
  3. imbalance of power between the bully and the victim (1, 2).

Bullying is also understood to be an interaction between at least two people during which a somehow stronger person (or group) gains power over a weaker person who is not able to defend himself. While the bullying process unfolds over time, the power imbalance increases. Thus, the longer a person is bullied, the more she gets trapped in the negative dynamic, and the more the perpetrator abuses her power.

In order to stop such bullying processes as early as possible it is important to understand the underlying mechanics that keep this negative process going. In research, mechanisms on the individual level, the dyadic ("two person") level and the group level have been identified. The main goal of this article is to highlight some most relevant findings on the mechanisms that operate at these three levels and to point out how they might be used for interventions.

Why Do Pupils Bully Others? (Individual Level)

Sense of Power

For perpetrators, one of the main motives to harass somebody weaker during a longer time span is to enjoy feeling the own power or dominance. That is, bullying others is a means by which the perpetrator can feel powerful and dominant. When the victim is scared or submissive the perpetrator reaches his or her goals and the negative behavior patterns are reinforced.

Wish for Affiliation

Our own research shows that perpetrators not only want to gain power or dominance when bullying others (3). A second important goal of bullying that we found was the perpetrator's wish for affiliation. Thus, perpetrators also bully others to be together with others, to feel close with (particular) others and to establish good relationships in their peer group. If this wish for affiliation is a motive for bullying, the victim plays an important role in establishing and maintaining group coherence. If the harassment of the victim leads to a closer bond within the bullying group, the perpetrator reaches his goal and the negative behavior is reinforced.

Why Do Pupils Bully Particular Victims? (Dyadic Level)

Unequal Relationship Between the Child and Who Bullies and The Victim

Children who bully others over a longer period of time usually target particular persons (4). Chronic victims often lack social support from others, and have no means of support during bullying episodes. Often victims are social outsiders and are rejected by many within the established peer group. Victims are usually non-aggressive students who are often shy and who have difficulty to defending themselves. By targeting this type of vulnerable pupils as victims, the risk for social disapproval or negative consequences for the perpetrator(s) is very low. After establishing this kind of unequal relationship between perpetrator and victim, the submissive, helpless, or fearful behavior of the victim itself reinforces the negative behavior of the perpetrator. These signs of pain and submission signal successful domination and control for the perpetrator. Thus, mechanisms on the dyadic level as well as on the whole group become important, since perpetrators often single out victims who already have a difficult status in the group.

Why Do Group Processes Play a Crucial Role? (Group Level)

Witnesses, Assistants, Reinforcers

Beside mechanisms on the individual and dyadic level, the influence of the whole class must not be overlooked. A study conducted in Finland (5) showed that beside the perpetrator and the victim many more pupils in a class play an important role during the bullying process. This research identified outsiders (these are pupils who don’t engage in bullying) as well as students who “assist” or “reinforce” the perpetrator by on-looking, laughing, etc. were found. Students who try to defend and help the victim were also identified. Research conducted in Canada (6) has demonstrated that peers are almost always present during bullying episodes, but only rarely intervene on behalf of the victim. Moreover, our own research (7) has demonstrated that there is a very high heterogeneity between classes in prevalence rates of perpetrators and victims. We both found very peaceful classes with no bullying and very violent ones in which up to half of the pupils were involved in bullying others.

Taken together, results of this study support the need to intervene on the group level and carefully tailor intervention efforts according to the needs of the particular classes. Sustainable effects will most likely with interventions that success in establishing prosocial norms for the group and positive social behavior (e.g., helping or integrating outsiders), not only in perpetrators but in the whole group.


  1. Olweus, D. (1991). Bully / victim problems among schoolchildren: Basic facts and effects of a school based intervention program. In D. J. Pepler & K. H. Rubin (Eds.), The development and treatment of childhood aggression (pp. 411-448). Hillsdale: Erlbaum.
  2. Roland, E., & Munthe, E. (1989). Bullying: An international perspective. London: David Fulton.
  3. Fandrem, H., Strohmeier, D. & Roland, E. (in press). Bullying and victimization among Norwegian and immigrant adolescents in Norway: The role of proactive and reactive aggressiveness. Journal of Early Adolescence.
  4. Veenstra, R., Lindenberg, S., Zijlstra, B.J.H., De Winter, A.F., Verhulst, F.C., & Ormel, J. (2007). The dyadic nature of bullying and victimization: Testing a dual-perspective theory. Child Development, 78, 6, 1843-1854.
  5. Salmivalli, C., Lagerspetz, K., Bjoerkqvist, K. & Oestermann K. (1996). Bullying as a group process: Participant roles and their relations to social status within the group. Aggressive Behaviour, Vol 22 (1), 1-15.
  6. Craig, Pepler & Atlas, 2000) Craig, W. M., Pepler, D., & Atlas, R. (2000). Observations of bullying in the playground and in the classroom. School Psychology International, 21(1), 22-36.
  7. Atria, M., Strohmeier, D. & Spiel, C. (2007). The relevance of the school class as social unit for the prevalence of bullying and victimization. European Journal of Developmental Psychology, 4 (4), 372-387.

Dr. Dagmar Strohmeier received her PhD 2006 at the University of Vienna, Austria. She holds a faculty position at the University of Vienna. Her main research interests are peer relations in cultural contexts and bullying prevention in schools.