Correlational studies show that prejudiced people attribute stigmatized traits to controllable causes, and blame stigmatized groups for their own fate. Attribution theory argues that causal attributions cause prejudice, and that changes in attributional beliefs produce changes in attitudes. In contrast, the justification–suppression model describes attributions to controllable causes as justifications of pre-existing prejudices. Study participants reported their attitudes toward 1 of 4 stigmatized groups, read information that manipulated their attributional beliefs, listed their thoughts, and reported their attitudes again. Supporting the suppression–justification model, initially prejudiced participants spontaneously produced more thoughts about the controllability of stigmatized identities. Refuting attribution theory, manipulating attributional beliefs had no effect on attitudes. Implications for applications of attribution theory to reduce prejudice are discussed.