Aggressive and violent behaviour among school pupils has become a research and public policy priority, owing to its consequences for children’s and young people’s development and academic performance and outcomes. This type of conduct, which is becoming a daily occurrence in schools and is known and to some extent sanctioned by adults and the students themselves, flies in the face of what is expected from school: a place where young citizens receive ethical, moral, emotional and cognitive education. It also seriously jeopardizes the school’s possibility of acting as a forum for the exchange of knowledge in a healthy and socially democratic and fair environment. Students must be able to learn without fear in a secure and reliable environment in order to build skills of all types and absorb the learning they need to develop comprehensively and participate fully in society.
Authors who have studied school bullying in order to understand or try to prevent it, or both, agree that Olweus was the first researcher to develop a framework and a set of criteria for describing violent behaviour among peers in the school setting. In the 1970s, Olweus (1978) raised the alert by denouncing aggression and abuse as a common and systemic practice among pupils in Norwegian schools. Today this phenomenon is known universally as “bullying”, which refers to different types of repeatedly occurring intimidation, harassment, abuse, mistreatment and victimization (Rigby, 1996; García, 2010).Bullying refers to repeated and ongoing situations of injustice and abuse of power (psychological or physical) and it has different, though all equally worrying, consequences for the students involved (Olweus, 1989, 1993, 1998; Smith and Sharpe, 1994; oecd, 2004; Cerezo, 2006; Skrzypiec, 2008). The available evidence distinguishes at least three actors in peer situations: (i) the student or students who do the harassing or bullying; (ii) the student or