Intervene or not to intervene? Students' reactions to school-bullyingwi,ssed and associated factors

School bullying often occurs in front of witnesses. These witnesses play a major role in the social dynamics which leads to assimilate this form of aggression to a group process. In the school setting, bystanders can either de fend the victim, behave as passive spectators or reinforce and assist the bully. Far from being massively oriented towards helping the mistreated student, the behavior of witnesses often reinforces the bully's sense of power and contributes to the victim's distress. The processes underlying these reactions as well as their effects on die protagonists of bullying and its perpetuation are now more widely documented. In this context, the present article aims to address the diversity of behaviors adopted by students observing bullying at school. Individual, psychosocial and contextual factors associated with these reactions will also be presented to better identify the lines of thought and intervention that can be developed.