Date of Award

Fall 12-2025

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

STEM Education & Professional Studies

Program/Concentration

Educational Psychology and Program Evaluation

Committee Director

Tony Perez

Committee Member

Linda Bol

Committee Member

Matt Henson

Abstract

Self-Determination Theory (SDT) posits that the quality of students’ motivation regulation (i.e., autonomous versus controlled) shapes both learning and health behavior, yet few studies have examined the relations among motivation regulation, alcohol and cannabis use, and achievement. In this study, I surveyed 459 undergraduates at a mid-sized public university in the southeastern United States. Participants completed the Academic Motivation Scale-College version 28 to assess autonomous and controlled motivation regulation, a typical-week alcohol grid, a seven-day cannabis grid, and self-reported grade point average (GPA). Results indicated that autonomous academic motivation was uniquely related to GPA; however, neither motivation variable related to alcohol or cannabis use once their shared variance was removed, and substance use did not mediate the motivation-achievement link. Age showed divergent slopes: before 21, each additional year was associated with higher drinking and cannabis use; after 21, drinking leveled off and cannabis use declined. Women reported marginally lower alcohol consumption than men, and students who identified with racial groups historically associated with higher prevalence of substance use earned lower GPAs than peers from lower prevalence groups. These results add contextual nuance to SDT. Consistent with prior research and theory, autonomous motivation relates positively to academic achievement even when controlling for developmental covariates and campus substance use. However, after accounting for developmental and contextual factors (including legal access at age 21), there was no relation between autonomous motivation and substance use. Practical implications include pairing autonomy-supportive advising and teaching with environmental measures (e.g., consistent policy enforcement, skills-based academic support) to promote both achievement and well-being. Limitations involve the cross-sectional, single-campus, self-report design; future longitudinal research with fine-grained substance assessments and additional SDT constructs (i.e., competence, relatedness) is recommended.

Rights

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

DOI

10.25777/nc78-sr13

ISBN

9798276042145

ORCID

0000000153031255

Download

Share

COinS