“…Though traditionally concerned with the behaviour of the 'bully' and the 'victim' (Olweus, 1988;Rigby & Slee, 1991), the mid-1990s saw studies published that accounted for the social context in which most school bullying takes place, that is, in the presence of others (DeRosier, Cillessen, Coie, & Dodge, 1994;Salmivalli, Voeten, & Poskiparta, 2011;Vannini et al, 2011; for a review, see Salmivalli, 2010). Naturalistic observations of school-yard bullying and self-report questionnaires revealed the triadic nature of bullying behaviour: 85% of observed bullying incidents in a Canadian school playground occurred in the presence of students who were not the 'bully' nor the 'victim', but 'bystanders' to the activity (Craig & Pepler, 1998).…”