likely to change their level of substance use over time in accord with their closest friend's level of substance use (e.g., to report relative increases when friend use was high at baseline, and relative decreases when friend use was low). The development of this measure continues a line of research suggesting that adolescent vulnerabilities to peer influence processes can be effectively assessed via hypothetical and analogue procedures (Allen et al., 2006). It also further extends past questionnaire studies of susceptibility by identifying a predictor that was explicitly constructed so as not to be simply a measure of general deviance proneness (Berndt, 1992).
