Agree to disagree: The role of competitive debate in fostering adolescents’ actively open-minded thinking

Despite its well-established predictive validity across indicators of rationality and sound decision-making, actively open-minded thinking (AOT) remains understudied in adolescent populations. Even less is known about educational activities that might cultivate AOT during adolescence. The present study had two aims: first, to examine the psychometric functioning of existing AOT items in adolescents, and second, to investigate whether participation in competitive debate is associated with longitudinal change in AOT. The first measurement point included 420 high school students (69.5% girls; M = 16.20 years). Longitudinal analyses included 161 participants (73.3% girls; M = 16.55 years), with the primary comparison focusing on 40 debaters and 101 non-debate/non-journalism students. Psychometric analyses indicated substantial item heterogeneity and method effects related to item keying. Although a shorter positively worded item subset showed good internal coherence, its construct coverage and criterion validity were more limited than expected. For the longitudinal analyses, we therefore prioritized broader construct coverage over factorial purity. Debaters showed an increase in AOT over the course of a single semester, whereas the non-debate comparison group remained essentially unchanged. Exploratory item-level analyses suggested that debate-related change was most visible in openness to opposing perspectives, engagement with disagreement, and active search for reasons why one might be wrong. Although the observational design prevents causal conclusions, the findings point to competitive debate as a promising context for fostering AOT in adolescence and highlight the need for future research using larger samples, additional measurement points, and multimethod assessments.