RESUMO
AIMS: To examine whether inclusion of both self- and peer-referent items in the context of a single social norms drinking questionnaire plays an active role in producing the much-reported tendency for young people to overestimate the extent of peers' alcohol-related behaviour and the permissiveness of their attitudes towards alcohol. DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS: In a between-subjects design pupils attending two Scottish secondary schools (n=1074; 12-18 years; 52.5% male) completed one of three questionnaires designed to measure a range of alcohol-related behaviours, attitudes and perceptions: a paradigmatic multiple-target questionnaire included self- and peer-referent items while two single-target questionnaires included self-referent or peer-referent items only. FINDINGS: Pupils' self-reported drinking behaviours and attitudes were similar, regardless of whether multiple or single-target versions of the questionnaire were used, as were perceptions of peers' frequencies of alcohol use and drunkenness. In contrast, by comparison with pupils who responded to a single-target version that omitted self-referent items, use of a multiple-target questionnaire was significantly more likely to result in reports that peers would consume alcoholic drinks when with friends and hold more permissive or liberal attitudes towards alcohol. CONCLUSIONS: Social norms research and related health promotion programmes that seek to reduce the extent of overestimation of peer drinking norms are heavily reliant upon multiple-target drinking questionnaires. The use of such a questionnaire may lead to more distorted or extreme perceptions being reported by pupils compared to single-target versions, which omit self-referent drinking items. By implication, use of multiple-target questionnaires may encourage young people to 'over-overestimate' peer drinking norms.