Beyond black and white: Reducing dichotomous thinking to foster intellectual humility

• Explored the link between dichotomous thinking and intellectual humility. • Dialectical treatment lowers dichotomous thinking, boosts intellectual humility. • Confirmed causal impact via instrumental variable estimation. • Findings suggest practical methods for increasing intellectual humility. This study examines the causal influence of dichotomous thinking on intellectual humility, evaluated through treatments designed to both increase and decrease dichotomous thinking. Employing an experimental design with 445 participants, we exposed experimental groups to either a black and white thinking treatment (high dichotomous thinking condition) or a dialectical thinking treatment (low dichotomous thinking condition), and then compared their intellectual humility scores to a control group. As hypothesized, significant differences in intellectual humility emerged among the groups. The most substantial effects were observed in the group exposed to the dialectical thinking treatment (low dichotomous thinking condition), where participants exhibited significantly elevated intellectual humility scores. Using instrumental variable estimation for the purposes of causal inference, we also confirmed that the mechanism by which the dialectical thinking treatment increased intellectual humility was by decreasing dichotomous thinking. Our study provides insights into the factors that influence intellectual humility and offers a practical method to enhance it through fostering dialectical thinking.