Assessing self-determined motivations for drinking alcohol via the Comprehensive Relative Autonomy Index for Drinking

Abstract

Objective: Self-Determination Theory (SDT) examines human motivation in multiple domains, facilitating comparison of motives across health behaviors. However, no existing measure assesses SDT-informed motives for drinking, which is necessary for understanding how SDT-based motives influence drinking and how drinking motives overlap with other health behavior motives. This study tested and cross-validated the structural and external validity of the SDT-informed Comprehensive Relative Autonomy Index for Drinking (CRAI-Drinking). Method: 630 adults (Mage=21.5, 55% female, 88% undergraduates) rated drinking motives on the CRAI-Drinking and Drinking Motives Questionnaire (DMQ), typical alcohol consumption, and negative and positive drinking consequences. Results: In Sample 1 (n=274), CRAI-Drinking item and subscale order aligned with SDT’s autonomy continuum. A five factor, 19-item model with factors for intrinsic, identified, positive introjected, external, and amotivation regulations (Cronbach’s α: 0.68-0.85) showed acceptable model fit in Sample 1 and in cross-validation Sample 2 (n=356). In the combined sample (n=630), CRAI-Drinking scores demonstrated convergent (r=0.45 to 0.76) and divergent (r=0.01 to 0.41) validity with the DMQ. Poisson regressions indicated that intrinsic (IRR=1.13) and identified (IRR=1.11) regulations were significantly associated with drinking frequency, identified (IRR=0.94) and positive introjected (IRR=1.08) regulations were significantly associated with drinking intensity, and amotivation (IRR=1.16) and intrinsic regulation (IRR=1.09) were associated with negative or positive consequences, respectively, after controlling for other CRAI-Drinking and DMQ factors, sex, and drinking intensity. Conclusions: The CRAI-Drinking provides unique information regarding associations between drinking motives, behaviors, and consequences, providing the first SDT-based measure of drinking motives enabling comparison of drinking motives with other health behavior motives.