There has been considerable debate regarding whether Social Dominance Orientation (SDO) constitutes a global individual difference that predicts prejudice or is instead a product of self-categorization processes. Two studies addressed this issue by contrasting the predictive and discriminant validity of SDO and reworded SDO items assessing prescriptive attitudes toward inequality and dominance based on specific stratifications. Consistent with a global individual difference perspective, SDO predicted systematic between-person consistencies in attitudes toward inequality based on specific group-based stratifications. Moreover, SDO and specific stratification attitudes exerted reciprocal cross-lagged effects on one another over five months (Study 1, N = 252). These results indicate that SDO is partially derived from specific attitudes and experiences (a bottom-up effect), but once formed, SDO exerts a reciprocal (top-down) effect on specific attitudes and cognitions about group-based dominance across a range of stratifications. Cross-sectional analyses indicated that SDO also predicted generalized prejudice toward ethnic groups after controlling for ethnic stratification attitudes (Study 2, N = 138). Taken together, these results indicate that SDO reflects a global motivation to achieve group-based dominance that is partially determined by situational factors but not reducible to self-categorization processes associated with attitudes towards specific social groups or categories.