When Mood Matters: Mood Effects on Key Constructs in Tpb

Ajzen’s (1985) theory of planned behavior (TPB) has been tested extensively in the field of adolescent drug prevention, and its predictive power is well documented in contemporary prevention research. Specifically, prevention studies often apply TPB to measure participants in classroom and small group settings, and assume that the measured attitudes and beliefs are generalizable to different contexts. However, these assumptions may not account for how attitudes might shift due to situational context, specifically salient affect. Recently, Ajzen (2011) noted that affect and emotions can act as factors that “influence behavioral, normative and/or control beliefs.” However, the implications of this knowledge have rarely been applied to prevention research, and how emotions may impact responses on TPB measures was, until now, unexplored.

The present study set out to examine how salient affect may influence participant responses on TPB measures targeting marijuana use. In the current study (N = 677) participants were randomly assigned in a 2 (mood manipulation: pleasant, unpleasant) by 4 (TPB measure: attitudes, subjective norms, perceived behavioral control, intentions) between subjects factorial design. An ANCOVA revealed a significant interaction of marijuana use and mood manipulation, F (1,149) = 3.54, p = .042. Participants in the pleasant condition who reported past use reported significantly higher positive attitudes towards marijuana use than never users in the unpleasant condition and all nonusers. However, never users in the unpleasant condition reported significantly higher positive attitudes towards marijuana use than participants reporting ever use. Subjective norms analyses revealed a significant main effect of mood manipulation with participants in the pleasant condition reporting significantly more favorable subjective norms towards marijuana than participants in the unpleasant condition, F (1,170) = 1.56, p = .01. These results provide preliminary support for the hypothesis that salient mood states may significantly impact key constructs in TPB, and demonstrate the need for prevention researchers to account for context in their designs