being bullied to stop it happening. We do not call it bullying when it is done in a friendly or playful way.” When bullying was reported, the interviewer asked the mother or child to describe what happened. An independent rater later checked notes taken by the interviewers to verify that the events described related to instances of bullying, operationally defined as evidence of repeated harmful actions between children where a power differential existed between the bully and the victim. This review was done blind to data on self harm. Mothers’ and children’s narratives of bullying experiences were coded as “never,” “yes, but isolated incidents,” or “frequently.” Children were also asked directly if they had been bullied “a lot.” Of the cohort children, 16.5% (350/2127) were reported by their mothers to have been frequently bullied before age 10, and 11.2% (237/2124) of the children reported themselves to have been bullied a lot before age 12.
