Five experiments investigated among nonsmokers with initial antismoking attitudes conformity to a norm of intergroup tolerance and nondiscrimination (i.e., a counterattitudinal norm) as a function of the personal versus categorical referent used in intergroup comparisons (self-categorization level), the motivation to respond without prejudice, and the perceived ingroup threat. Results showed that conformity (i.e., a reduction of support for antismoking actions) was moderated by the ingroup threat in the category-referent condition (i.e., conformity was observed only when the perceived threat was low), but by the internal motivation to respond without prejudice in the personal-referent condition. These findings suggest the existence of different moderators of conformity as a function of the self-categorization level.