# Jim Sidanius American social psychologist (1945–2021), Professor of Psychology and African American Studies at Harvard. Co-developer with Felicia Pratto of *Social Dominance Theory* and the *Social Dominance Orientation* (SDO) scale — the second major instrument (alongside Altemeyer's RWA) in the contemporary empirical study of authoritarian-and-prejudice dispositions. The SDO scale measures preference for hierarchical *group* relations — anti-egalitarianism, support for in-group dominance over out-groups. The dual-process model (Duckitt) frames RWA and SDO as measuring different paths to authoritarian outcomes: RWA captures submission-and-conventionalism (under threat conditions), SDO captures preference-for-hierarchy (under competitive-resource conditions). The two scales correlate moderately and combine multiplicatively to predict the most extreme prejudice and political-violence support. Sidanius and Pratto's *Social Dominance: An Intergroup Theory of Social Hierarchy and Oppression* (1999) is the canonical statement of the broader theory, integrating individual-differences psychology with group-conflict and hierarchy-maintenance dynamics. ## Academic Career **Jim Sidanius** was born in **1945** and earned his **Ph.D. in psychology** from the **University of Stockholm**, Sweden. He held faculty positions at **New York University**, **Carnegie Mellon University**, the **University of California, Los Angeles** (where much of the SDO research was developed), and finally **Harvard University** (2006–2021), where he held a joint appointment as Professor of Psychology and Professor of African and African American Studies. He died on **May 18, 2021**. ## Social Dominance Orientation (1994) The **SDO scale** — published in **1994** by Sidanius, [[Felicia Pratto]], Lisa M. Stallworth, and Bertram F. Malle in the *Journal of Personality and Social Psychology* — measures an individual's preference for **hierarchical relations between social groups**: the degree to which one supports the idea that some groups should dominate others. High-SDO individuals favor inequality, social hierarchy, and the subordination of out-groups; low-SDO individuals favor egalitarianism and equal treatment. The SDO scale is the **complementary instrument** to [[Bob Altemeyer]]'s RWA scale. The dual-process model (developed by John Duckitt) frames the two as measuring **different psychological pathways** to authoritarian outcomes: RWA captures **submission-and-conventionalism** (activated by perceived threat to social order), while SDO captures **dominance-and-anti-egalitarianism** (activated by perceived competition for resources and status). The two scales correlate moderately (r ≈ .20–.40 in most samples), and the individuals who score high on *both* — Altemeyer's **"Double Highs"** — predict the most extreme prejudice, support for political violence, and authoritarian political behavior. ## *Social Dominance* (1999) ***Social Dominance: An Intergroup Theory of Social Hierarchy and Oppression*** (Cambridge, 1999, with Pratto) — the canonical theoretical statement. Social Dominance Theory argues that all human societies develop **group-based hierarchies** (not just individual hierarchies) in which at least one group dominates at least one other, and that these hierarchies are maintained through three mechanisms: **individual discrimination**, **institutional discrimination**, and **behavioral asymmetry** (in which subordinate groups sometimes act in ways that reinforce the hierarchy). The theory integrates individual-differences psychology (SDO) with structural-intergroup-relations analysis. The book has been replicated across cultures worldwide, with the SDO scale showing robust measurement properties across dozens of national contexts — supporting the claim that preference-for-group-hierarchy is a cross-cultural individual-difference variable, not merely a Western-specific construct. ## KB Significance Sidanius (with Pratto) developed the **second pillar** of contemporary empirical authoritarianism research: where Altemeyer's RWA measures conformity-and-submission, SDO measures dominance-and-hierarchy-preference. The two instruments together provide a comprehensive individual-level framework for understanding why people support authoritarian movements — some driven by perceived threat to social order (RWA), some by desire to maintain group dominance (SDO), and the most dangerous actors driven by both. ## See Also - [[Felicia Pratto]] — co-developer - [[Bob Altemeyer]] — RWA-scale parallel - [[Authoritarianism]] - [[Right-Wing Authoritarianism]]