Although the majority of children and adolescents express a genuine dislike for anti-social behaviour which causes distress to peers, only around 10 per cent regularly intervene to stop it (Pepler, 1996; Rigby Slee, 1991). One powerful reason for this inaction comes from pressure on the part of the peer group on bystanders, including those who feel sympathy for the victim, to take the safe line of non-intervention.