A group of 45 undergraduates discussed a moral issue with a confederate who had the same opinion (no-controversy) or opposite opinion (controversy). Subjects in the controversy conditions were induced to have a high level of defensiveness by a disconfirmation of personal competence or a low level of defensiveness by a confirmation. Subjects in no-controversy indicated more conceptual conflict (uncertainty) and were more accurate in taking the cognitive perspective of the confederate than were subjects in the confirm no-controversy condition. These results support Piaget's and Kohlberg's views of the role of controversy in perspective-taking and cognitive development and Berlyne's theory of conceptual conflict and epistemic curiosity. Subjects in the disconfirm controversy condition experienced more uncertainty and were more accurate in cognitive perspective-taking than were subjects in the confirm controversy condition. Subjects in the disconfirm controversy condition also experienced more internal distress, derogated the confederate and the confederate's position and arguments to a greater extent, and indicated greater closed-mindedness in responding to the confederate and the confederate's arguments than did subjects in the confirm controversy condition. (Author)