Social Dominance Orientation and Right-Wing Authoritarianism: Additive and Interactive Effects

The additive and interactive effects of Social Dominance Orientation (SDO) and Right-Wing Authoritarianism (RWA) were examined using 16 independent samples of New Zealand European participants (N = 2,164). Consistent with Duckitt's (2001) Dual Process Model, SDO and RWA displayed strong additive effects across various domains of intergroup-related attitude, including measures of racism, sexism, homosexual prejudice, and ethnic and religious ingroup identification. In each of these five domains, meta-analysis indicated that the statistical interaction of SDO and RWA accounted for an average of less than .001% variance in addition to their linear combination. It is concluded that the association between SDO and various discriminatory attitudes and beliefs is only extremely weakly dependent on RWA, and vice-versa, suggesting that these two ideological attitudes are primarily additive, rather than interactive, in nature.