Moral foundations theory (MFT) argues that liberals and conservatives form different moral positions because liberals emphasize the values of harm and fairness, whereas conservatives emphasize the values of group loyalty, authority, and purity. In five studies (total N = 3,327), we investigated whether political orientation moderated the relationship between the perceived relevance of each moral foundation and moral conviction (i.e., the extent to which one perceives their attitude as based on morality) across four issues. Political differences in this relationship emerged but were inconsistent across issues and did not always align with the predictions of MFT or several other theoretical explanations. Our findings together with previous research indicate that MFT may do a better job predicting attitude position than it does predicting whether people perceive that their attitudes are moral convictions, and that some foundations may reflect conventional rather than moral values (e.g., authority).
Keywords: domain theory; dyadic morality; moral conviction; moral foundations; morality.