Introduction <p>Prejudice against lesbians and gay men (PALG) remains a persistent social problem shaped by both cognitive and motivational processes. Yet relatively few studies have experimentally tested scalable interventions for reducing PALG or examined whether their effects vary as a function of internalized motivation to respond without prejudice.</p> Methods <p>A total of 140 Chinese university students participated in a randomized intervention study with pre-screened internalization strata. Participants were assigned to either a brief domain-specific critical thinking training condition or a content-neutral control condition. Internalized motivation to respond without prejudice was analyzed as a continuous moderator using PROCESS Model 1, with gender, traditional gender role beliefs, and pre-test intergroup closeness included as covariates.</p> Results <p>Critical thinking training significantly reduced post-test PALG, and this effect was moderated by internalized motivation to respond without prejudice. Conditional-effect analyses showed that the intervention was especially effective at lower internalization. At higher internalization, the additional benefit of the intervention was not statistically significant.</p> Conclusion <p>These findings suggest that brief domain-specific critical thinking training can reduce PALG, particularly among individuals with lower internalization of motivation to respond without prejudice. The results highlight the value of considering motivational internalization when designing and evaluating prejudice-reduction interventions.</p> Policy Implications <p>Given its low cost, digital scalability, and ease of integration into higher education curricula, this intervention has potential policy relevance for improving campus climate, guiding more efficient allocation of diversity resources, and informing tailored prejudice-reduction strategies within institutional programming.</p>