Background:  Cyberbullying describes bullying using mobile phones and the internet. Most previous studies have focused on the prevalence of text message and email bullying. Methods:  Two surveys with pupils aged 11–16 years: (1) 92 pupils from 14 schools, supplemented by focus groups; (2) 533 pupils from 5 schools, to assess the generalisability of findings from the first study, and investigate relationships of cyberbullying to general internet use. Both studies differentiated cyberbullying inside and outside of school, and 7 media of cyberbullying. Results:  Both studies found cyberbullying less frequent than traditional bullying, but appreciable, and reported more outside of school than inside. Phone call and text message bullying were most prevalent, with instant messaging bullying in the second study; their impact was perceived as comparable to traditional bullying. Mobile phone/video clip bullying, while rarer, was perceived to have more negative impact. Age and gender differences varied between the two studies. Study 1 found that most cyberbullying was done by one or a few students, usually from the same year group. It often just lasted about a week, but sometimes much longer. The second study found that being a cybervictim, but not a cyberbully, correlated with internet use; many cybervictims were traditional ‘bully‐victims’. Pupils recommended blocking/avoiding messages, and telling someone, as the best coping strategies; but many cybervictims had told nobody about it. Conclusions:  Cyberbullying is an important new kind of bullying, with some different characteristics from traditional bullying. Much happens outside school. Implications for research and practical action are discussed.

School‐based surveys of reports of being bullied reveal a fairly steady downward trend through ages eight to 16 years. Four hypotheses are examined which may explain this age‐related decline: (1) younger children have more children older than them in school, who are in a position to bully them; (2) younger children have not yet been socialized into understanding that you should not bully others; (3) younger children have not yet acquired the social skills and assertiveness skills to deal effectively with bullying incidents and discourage further bullying; and (4) younger children have a different definition of what bullying is, which changes as they get older. We test these hypotheses against existing data, and new data, in Study A from interviews with 48 pupils (aged seven‐eight, nine‐ten, 11‐12 and 13‐14 years); and in Study B from interviews with 159 participants (aged five‐six, nine‐ten, 15‐16 and 18‐29 years). The relative strength of the four hypotheses is evaluated. There is support for both (1) and (3); (2) appears to have little impact before age 15; and (4) may explain high rates of report in children under nine years. Implications of these findings are discussed.