Social identity as a moderator of the association between perceived norms and marijuana use.

OBJECTIVE: This study extends previous examinations of social influences and marijuana use in considering how heavy marijuana users view themselves relative to their peers. We were specifically interested in evaluating whether (a) heavy-using marijuana users would identify more strongly with other users than with typical students, (b) identification with other marijuana users would be more strongly associated with own use, and (c) the association between perceived norms and marijuana use would be moderated by identification with peers.
METHOD: Participants were 107 heavy (five or more times per month) marijuana users who completed an online survey assessing perceived norms for marijuana use, identification with typical students and other marijuana-using students, and marijuana use (frequency of use, joints per week, and hours high).
RESULTS: Participants unexpectedly identified more strongly with typical students rather than with other marijuana-using students. Identification with other marijuana users was, however, associated with more use. In addition, perceived norms were associated with more use but primarily among those who identified more with other users but not with typical students.
CONCLUSIONS: Heavy marijuana users may be reluctant to identify themselves as users and may prefer to think of themselves as typical students. This may provide clinical opportunities to highlight discrepancies. In addition, identification with other users and lack of identification with typical students may be risk factors for heavier use and good indicators of candidacy for norms-based interventions. In sum, the present findings extend our understanding of the influence of social identity among young adult marijuana users and suggest novel directions for intervention strategies.