Social dominance orientation: The motivational basis of intergroup inequality

Group-based hierarchies govern much of social life, from relations between ethnic groups to those between nation-states. We review three decades of research on social dominance orientation (SDO), or individual differences in the preference for group-based hierarchy and inequality. We show that SDO functions as the motivational basis of intergroup inequality, demonstrating this through examples of our research on its meaning, significance, and etiology. Our work has developed the conceptualization of SDO and shown that it drives hierarchy maintenance (vs. challenge) in myriad ways, functioning as the ideological glue that guides individuals’ hierarchy-regulating cognition across contexts. Our work further suggests that SDO arose as an adaptive orientation to help humans navigate social hierarchies, building on understandings of hierarchical social arrangements even in preverbal infants, and exhibiting variation that is to a substantial degree genetically heritable. Still, as predicted by social dominance theory twenty-five years ago, SDO levels are flexibly adapted to the affordances of particular social contexts and a group's hierarchical position therein. Throughout, we identify outstanding questions for future research in which SDO exhibits its potency and relevance as the motivational basis of multilevel accounts of intergroup inequality.