Two sides of the same coin? On the common etiology of Right-Wing Authoritarianism and Social Dominance Orientation

Right-Wing Authoritarianism (RWA) and Social Dominance Orientation (SDO) are often regarded as two basic dimensions of individual differences in socio-political attitudes. Since both RWA and SDO are powerful pre-dictors of various kinds of political beliefs and prejudices, a fair amount of prior research has been conducted to examine etiological factors contributing to individual differences in both. According to the Dual Process Model (DPM), RWA and SDO are each caused by distinct personality dispositions and socialization experiences. The present study examines these assumptions using data from the German TwinLife study. Applying a bivariate Cholesky design, data from 3177 twins and their siblings were used to calculate genetic and environmental correlations. We found a very high genetic correlation (rA = 0.943) and bivariate heritability (83.04 %), whereas nonshared and shared environmental effects were negligible. The results are consistent with the assumptions of the DPM on the distinct influence of environmental factors on RWA and SDO but, in contrast, indicate a common genetic basis. Following previous findings, we argue that this may be the same genetic basis underlying openness to experience. Further theoretical implications regarding the emergence of differences in sociopolitical attitudes are discussed.