Social Dominance Orientation (SDO)

Abstract

The Social Dominance Orientation (SDO) scale, originally developed and validated by Felicia Pratto, Jim Sidanius, Lisa M. Stallworth, and Bertram F. Malle in 1994, is one of the most prominent psychometric instruments in political psychology, personality assessment, and intergroup relations. Grounded in Social Dominance Theory (SDT), the scale operationalizes an individual’s general attitudinal disposition toward group-based inequality and intergroup hierarchy—specifically the extent to which an individual prefers relations between social groups to be equal versus hierarchical, and desires that in-groups dominate out-groups. The standard 16-item version (frequently designated as SDO-6) measures this construct using balanced phrasing: eight protrait items reflecting group domination and superiority, and eight contrait (reverse-scored) items indexing preference for group equality. Responses are evaluated on a 7-point Likert-type scale ranging from 1 (very negative) to 7 (very positive).

Decades of psychometric research confirm that the SDO scale possesses robust internal consistency (Cronbach’s $\alpha$ routinely exceeding .85 across cross-national cohorts) and strong test-retest reliability across multiple longitudinal waves. Psychometric debates regarding the scale’s dimensional structure have evolved from an initial unidimensional model to bifactor and two-dimensional formulations capturing SDO-Dominance (active subjugation and overt aggression between groups) and SDO-Egalitarianism / Anti-Egalitarianism (opposition to group equality and preference for systemic stratification), as consolidated by Ho et al. (2012). SDO demonstrates formidable predictive and construct validity, reliably predicting systemic racism, ethnocentrism, sexism, opposition to redistributive social policies, support for militarism, punitive criminal justice policies, and career self-selection into hierarchy-enhancing versus hierarchy-attenuating institutions. In conjunction with Right-Wing Authoritarianism (RWA) within Duckitt’s Dual-Process Cognitive-Motivational Model, SDO stands as a foundational anchor for empirical research on the psychological origins of structural inequality, discrimination, and political polarization.

Keywords

Social Dominance Orientation, SDO, Social Dominance Theory, Intergroup Relations, Group-Based Hierarchy, Prejudice, Discrimination, Authoritarianism, Political Psychology, Psychometrics, Legitimizing Myths, Anti-Egalitarianism

Authors

The foundational 16-item Social Dominance Orientation scale (SDO-6) was formulated and validated by:

• Felicia Pratto, Ph.D. — Professor of Psychological Sciences, Department of Psychological Sciences, University of Connecticut, Storrs, Connecticut, USA. Specializes in social psychology, intergroup power relations, social cognition, and intergroup attitudes.
• Jim Sidanius, Ph.D. (1945–2021) — Former John Lindsley Professor of Psychology in memory of William James and Professor of African and African American Studies, Department of Psychology, Harvard University, Cambridge, Massachusetts, USA. Co-originator of Social Dominance Theory and pioneer in political psychology, intergroup conflict, and systemic inequality.
• Lisa M. Stallworth, Ph.D. — Formerly affiliated with the Department of Psychology, Stanford University, Stanford, California, USA. Contributed extensively to the initial empirical instrumentation and validation of the SDO construct.
• Bertram F. Malle, Ph.D. — Professor of Cognitive, Linguistic, and Psychological Sciences, Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, Rhode Island, USA. Specialist in social cognition, moral judgment, and psychometric methodology.

Subsequent psychometric refinements, structural bifactor reappraisals, and short-form developments were introduced by Arnold K. Ho (University of Michigan), Jim Sidanius, Felicia Pratto, Shana Levin (Claremont McKenna College), Lotte Thomsen (University of Oslo / Aarhus University), Nour Kteily (Northwestern University), and Jennifer Sheehy-Skeffington (London School of Economics and Political Science).

Purpose

The primary purpose of the Social Dominance Orientation (SDO) scale is to quantitatively measure an individual’s chronic generalized preference for group-based hierarchy, inequality, and domination of subordinate social groups by dominant groups. Unlike constructs that measure localized ethnic, racial, or national antipathy—such as anti-Black racism, xenophobia, or antisemitism—SDO was engineered as a broad, content-general personality variable and ideological orientation. It captures an underlying motivational goal: the belief that the world is an intrinsically competitive jungle wherein social hierarchies are natural, inevitable, and desirable.

Theoretical and Research Applications

Within empirical social, political, and personality psychology, the scale serves several essential research purposes:

• Predicting Generalized Prejudice: SDO serves as one of the most potent predictors of systemic out-group prejudice across diverse contexts. Individuals with elevated SDO scores consistently exhibit prejudice not merely toward a single out-group, but across multiple, unrelated marginalized categories, including racial and ethnic minorities, immigrants, sexual minorities, religious minorities, and socioeconomically disadvantaged populations.
• Explaining Policy Preferences: The scale differentiates individuals across their stances on socio-political public policy. SDO systematically predicts opposition to affirmative action, wealth redistribution, environmental conservation, social safety nets, universal healthcare, and human rights treaties, while positively predicting endorsement of aggressive foreign military interventions, capital punishment, severe criminal sentencing, and anti-immigration legislation.
• Institutional Selection and Role Allocation: SDO provides empirical insight into how individuals select into, are hired by, and thrive within distinct institutional environments. Social Dominance Theory posits that institutions operate along a continuum from hierarchy-enhancing (HE; e.g., corporate law firms, military organizations, police departments, prosecution offices) to hierarchy-attenuating (HA; e.g., civil rights organizations, public defenders’ offices, social services, humanitarian aid groups). SDO reliably predicts institutional sorting, occupational preferences, and career tenure across these divergent organizational domains.

Clinical and Applied Diagnostics

Although the SDO scale is primarily deployed within empirical research settings rather than as a clinical diagnostic tool for psychological disorders, it provides substantial diagnostic value in applied social settings. Organizational psychologists utilize SDO metrics to assess institutional climate, identify vulnerabilities to discriminatory hiring practices, evaluate readiness for diversity and equity initiatives, and study intergroup power dynamics within corporate and public governance structures. In forensic and high-stakes law enforcement assessment, evaluating social dominance tendencies assists researchers in identifying behavioral patterns regarding systemic bias, institutional force, and intergroup hostility.

Psychological Construct

Social Dominance Orientation represents a core ideological orientation that reflects an individual’s endorsement of group-based inequality. The construct is situated at the intersection of personality psychology, social cognition, and political ideology. Individuals high in SDO endorse a world paradigm wherein dominant groups rightfully maintain disproportionate access to material wealth, social prestige, political power, and civil liberties, while subordinate groups occupy subordinate socioeconomic strata.

Core Dimensionality: Dominance vs. Anti-Egalitarianism

Although originally conceptualized and scored as a single continuous dimension (ranging from total commitment to intergroup egalitarianism to intense preference for intergroup domination), contemporary psychometric evidence demonstrates that SDO encompasses two distinct yet correlated sub-dimensions (Ho et al., 2012):

• SDO-Dominance (SDO-D): Captures an individual’s explicit preference for active, forceful, and oppressive subjugation of out-groups by dominant in-groups. It reflects support for zero-sum, aggressive intergroup dominance (“To get ahead in life, it is sometimes necessary to step on other groups”). SDO-D is strongly tied to explicit intergroup aggression, active discrimination, militaristic foreign policy attitudes, overt ethnic hostility, support for state-sanctioned violence, and lower empathy.
• SDO-Anti-Egalitarianism (SDO-E): Measures opposition to group equality and support for systemic, institutionalized status hierarchies (“Group equality should be our ideal” [reverse-scored]; “We should strive to make incomes as equal as possible” [reverse-scored]). SDO-E reflects a preference for maintaining existing social stratification and opposing hierarchy-attenuating policies, such as welfare, affirmative action, and social redistribution, often justified through meritocratic and conservative ideologies rather than explicit physical violence.

Relationship with Personality Architecture

Within the framework of the Five-Factor Model (Big Five) of personality, SDO demonstrates a distinct profile. Most prominently, SDO displays a strong, consistent negative correlation with Agreeableness ($r \approx -.30$ to $-.45$), capturing an orientation characterized by tough-mindedness, low empathy, lack of altruism, and competitive social striving. To a lesser degree, it correlates negatively with Openness to Experience, reflecting reduced tolerance for cultural diversity and novel socio-political arrangements.

In relation to the HEXACO model, SDO shares a profound negative association with the Honesty-Humility dimension, highlighting individuals who are willing to exploit others for personal or group advancement. SDO also overlaps significantly with the Dark Triad traits, particularly Machiavellianism and subclinical psychopathy, reflecting instrumental, manipulative, and unfeeling approaches toward human social systems.

Theoretical Framework

The theoretical bedrock of the SDO instrument is Social Dominance Theory (SDT), an overarching framework formulated by Jim Sidanius and Felicia Pratto (Sidanius & Pratto, 1999). SDT seeks to explain how group-based hierarchies are produced, maintained, and stabilized across human societies. The theory begins with the evolutionary and historical observation that all human social systems exhibiting economic surplus organize themselves into group-based social hierarchies containing three universal systems of stratification:

1. Age System: Wherein older individuals exercise disproportionate authority over younger individuals.
2. Gender/Sex System: Wherein males hold greater social, military, and political power relative to females (the “iron law of andrarchy”).
3. Arbitrary-Set System: Wherein socially constructed categories (such as race, ethnicity, nationality, caste, tribe, or religious affiliation) are arrayed in hierarchical tiers of power and access to capital.

Legitimizing Myths: Hierarchy-Enhancing vs. Hierarchy-Attenuating

SDT posits that social stability in stratified systems is maintained not purely through force, but through culturally shared ideologies termed legitimizing myths. These myths consist of attitudes, values, beliefs, and institutionalized dogmas that justify social arrangements:

• Hierarchy-Enhancing (HE) Legitimizing Myths: Provide moral and intellectual justification for group-based inequality. Examples include racism, sexism, nationalism, internal attribution of poverty, meritocratic fundamentalism, and social Darwinism. High SDO individuals consistently endorse HE myths to legitimize existing power differentials.
• Hierarchy-Attenuating (HA) Legitimizing Myths: Advocate for group equality, civil rights, egalitarianism, universal human rights, and social justice. Low SDO individuals disproportionately endorse HA myths to dismantle established stratification systems.

The Dual-Process Cognitive-Motivational Model

Within contemporary political psychology, SDO is most effectively contextualized alongside John Duckitt’s Dual-Process Cognitive-Motivational Model of Ideology and Prejudice (Duckitt, 2001). Duckitt demonstrates that socio-political ideology and generalized out-group hostility stem from two distinct cognitive-motivational pathways:

By assessing both SDO and RWA simultaneously, researchers can account for exceptionally high proportions of variance ($R^2$ frequently between .45 and .70) in generalized prejudice, political conservatism, and authoritarian policy preferences.

Validity

The construct, convergent, discriminant, and predictive validity of the SDO scale have been documented in hundreds of independent empirical investigations across multiple continents and political systems.

Construct and Convergent Validity

In their seminal validation study across 13 distinct adult and student samples ($N > 2,600$), Pratto et al. (1994) established that SDO converges robustly with measures indexing intergroup antipathy and dominance attitudes. SDO exhibits substantial positive correlations with:

• Explicit and implicit racial prejudice and ethnic out-group rejection ($r = .35$ to $.58$).
• Hostile and benevolent sexism ($r = .30$ to $.52$).
• Cultural and political nationalism ($r = .40$ to $.60$).
• Support for aggressive foreign policy and defense spending ($r = .33$ to $.48$).
• Belief in a Just World and Protestant Work Ethic myths used to justify economic disparities ($r = .25$ to $.40$).

Discriminant Validity

The discriminant validity of SDO is highlighted by its empirical separation from Right-Wing Authoritarianism and general political conservatism. Although SDO, RWA, and conservatism often correlate positively in Western democracies ($r \approx .20$ to $.45$), factor-analytic and structural equation models confirm they represent distinct latent constructs:

• SDO predicts prejudice toward socially disadvantaged or low-status groups regardless of whether those groups present a cultural threat, whereas RWA uniquely predicts prejudice toward groups perceived as violating normative social order.
• Discriminant validity is further demonstrated across psychological well-being measures: SDO shows virtually zero correlation with generalized self-esteem, clinical anxiety, or depression, proving it is not a proxy for general neurotic distress or personal maladjustment.

Predictive and Ecological Validity

SDO displays remarkable ecological and predictive validity in real-world environments. In occupational psychology, Sidanius et al. (1994) and subsequent cross-cultural replications demonstrated that individuals high in SDO systematically gravitate toward hierarchy-enhancing roles (e.g., law enforcement officers, corporate litigation attorneys, institutional security personnel), whereas individuals low in SDO select hierarchy-attenuating careers (e.g., social workers, human rights litigators, civil liberties advocates). In laboratory settings, high SDO participants assigned to positions of authority allocate significantly fewer resources to subordinate out-group members, display lower levels of prosocial cooperation in mixed-motive economic games, and endorse harsher interrogation methods on captured adversaries.

Reliability

The SDO scale demonstrates high empirical reliability across diverse demographic strata, cultures, and languages.

Internal Consistency

In the original validation studies by Pratto et al. (1994), the 16-item scale demonstrated Cronbach’s alpha coefficients ranging between $\alpha = .83$ and $\alpha = .91$ across diverse undergraduate and community samples. Subsequent large-scale meta-analyses and cross-national surveys have corroborated these figures:

• General adult samples consistently yield Cronbach’s $\alpha$ coefficients between $.85$ and $.92$.
• When analyzed as two separate subscales (Ho et al., 2012), both SDO-Dominance (8 items) and SDO-Egalitarianism (8 items) retain strong internal consistency, typically yielding $\alpha$ coefficients between $.80$ and $.89$.
• McDonald’s omega ($\omega$) coefficients consistently track or exceed alpha levels, demonstrating that the presence of reversed items does not degrade composite measurement reliability.

Test-Retest Stability

SDO was formulated as a relatively stable socio-ideological orientation. Longitudinal investigations substantiate its temporal consistency:

• Over intervals ranging from several months to a full calendar year, test-retest correlations consistently range from $r_{tt} = .70$ to $.84$ among adult populations.
• Multi-year panel studies tracking university students from matriculation to graduation (Sidanius et al., 2004) revealed stable individual rank-order continuity coefficients ($r > .60$), even while mean scores shifted slightly in response to major sociopolitical socialization events.

Factor Analysis

The latent structure of the Social Dominance Orientation scale has generated substantial empirical discourse, evolving from early unidimensional models to advanced multidimensional and bifactor representations.

Exploratory Factor Analysis (EFA)

Initial Exploratory Factor Analyses conducted by Pratto et al. (1994) indicated a dominant first principal factor that accounted for substantial overall item variance (typically between 30% and 45%). A two-factor extraction consistently distinguished between the protrait items (Items 1–8: dominance and hierarchy) and contrait items (Items 9–16: equality and leveling). Although Pratto et al. initially regarded this split as a method artifact attributable to item phrasing directionality, subsequent psychometric research established that this division carried deep theoretical significance.

Confirmatory Factor Analysis (CFA) and Bifactor Models

Methodological work by Ho et al. (2012) across multiple diverse samples definitively established that a correlated two-factor model or a bifactor model fits empirical covariance matrices substantially better than a single-factor unidimensional model:

Standardized factor loadings for items on their respective target factors routinely range from $lambda = .55$ to $.82$. While the bifactor model demonstrates superior global fit indices, researchers frequently retain the aggregate composite SDO score when exploring broad political behaviors, or break out SDO-D and SDO-E when distinguishing between active violent intergroup hostility versus passive opposition to redistributive equality.

Cross-Cultural Measurement Invariance

Cross-national validation studies spanning North America, Western and Eastern Europe, the Middle East, East Asia, and Latin America have subjected the SDO scale to multi-group confirmatory factor analysis (MGCFA). These evaluations support configural and metric invariance across diverse linguistic cohorts, proving that the latent construct of group-based dominance operates across distinct national power systems. In some non-Western or post-conflict societies, minor item-level non-invariance emerges primarily on socioeconomic leveling items (such as Item 15), reflecting local macroeconomic conditions rather than structural construct failure.

Instrument / Measurement Tool

The standard instrument details for the 16-item Social Dominance Orientation scale (SDO-6) are outlined below:

• Construct Measured: Preference for group-based social hierarchy and inequality versus group equality.
• Total Item Count: 16 items.
• Subscale Breakdown:
  • Dominance (SDO-D): Items 1, 2, 3, 4, 5, 6, 7, 8.
  • Anti-Egalitarianism / Equality (SDO-E): Items 9, 10, 11, 12, 13, 14, 15, 16.
• Response Scale: 7-point Likert-type rating scale:
  • 1 = very negative
  • 2 = negative
  • 3 = slightly negative
  • 4 = neither positive nor negative
  • 5 = slightly positive
  • 6 = positive
  • 7 = very positive
• Scoring Rules:
  • Item Inversion: Items 9, 10, 11, 12, 13, 14, 15, and 16 are reverse scored using the formula: $Score_{reversed} = 8 – Score_{original}$.
  • Overall SDO Score: Calculated as the arithmetic mean of all 16 items (after reverse scoring Items 9–16). Higher mean scores (ranging from 1 to 7) represent higher levels of Social Dominance Orientation.
  • Subscale Scores:
    • SDO-Dominance Mean: Mean of Items 1 to 8.
    • SDO-Anti-Egalitarianism Mean: Mean of reverse-scored Items 9 to 16.
• Administration Time: Approximately 3 to 5 minutes.

Permissions & Fee and Test Year

The 16-item Social Dominance Orientation (SDO-6) scale was first published in 1994 by Felicia Pratto, Jim Sidanius, Lisa M. Stallworth, and Bertram F. Malle in the Journal of Personality and Social Psychology. The instrument is situated within the public domain for academic, scientific, non-commercial research, and pedagogical purposes. No license fees or formal royalties are mandated for academic researchers deploying the scale.

Investigators utilizing the scale are expected to cite the original validation publication (Pratto et al., 1994) along with key structural reconsiderations where applicable (Ho et al., 2012). Commercial applications, integration into proprietary corporate pre-employment screening batteries, or publication within fee-restricted commercial software platforms require prior consultation with the copyright owners and publisher (American Psychological Association).

References

• Duckitt, J. (2001). A dual-process cognitive-motivational theory of ideology and prejudice. Advances in Experimental Social Psychology, 33, 41–113. https://doi.org/10.1016/S0065-2601(01)80004-6
• Ho, A. K., Sidanius, J., Pratto, F., Levin, S., Thomsen, L., Kteily, N., & Sheehy-Skeffington, J. (2012). Social dominance orientation: Revisiting the structure and function of a variable predicting social and political attitudes. Personality and Social Psychology Bulletin, 38(5), 583–606. https://doi.org/10.1177/0146167211432765
• Jost, J. T., Glaser, J., Kruglanski, A. W., & Sulloway, F. J. (2003). Political conservatism as motivated social cognition. Psychological Bulletin, 129(3), 339–375. https://doi.org/10.1037/0033-2909.129.3.339
• Kteily, N., Ho, A. K., & Sidanius, J. (2012). Hierarchy in the mind: The predictive ability of social dominance orientation on behavior in and attitudes toward social hierarchies. Social and Personality Psychology Compass, 6(8), 543–560. https://doi.org/10.1111/j.1751-9004.2012.00448.x
• Pratto, F., Sidanius, J., Stallworth, L. M., & Malle, B. F. (1994). Social dominance orientation: A personality variable predicting social and political attitudes. Journal of Personality and Social Psychology, 67(4), 741–763. https://doi.org/10.1037/0022-3514.67.4.741
• Sidanius, J., & Pratto, F. (1999). Social dominance: An intergroup theory of social hierarchy and oppression. Cambridge University Press. https://doi.org/10.1017/CBO9781139175043
• Sidanius, J., Pratto, F., & Bobo, L. (1996). Racism, conservatism, affirmative action, and intellectual sophistication: A matter of ideological consistency or ideological dominance? Journal of Personality and Social Psychology, 70(3), 476–490. https://doi.org/10.1037/0022-3514.70.3.476
• Sidanius, J., Pratto, F., Sinclair, S., & van Laar, C. (1996). Mother Teresa meets Genghis Khan: The dialectics of hierarchy-enhancing and hierarchy-attenuating social roles. Social Justice Research, 9(2), 145–169. https://doi.org/10.1007/BF02198077
• Sidanius, J., Pratto, F., van Laar, C., & Levin, S. (2004). Social dominance theory: Its agenda and method. Political Psychology, 25(6), 845–880. https://doi.org/10.1111/j.1467-9221.2004.00401.x

Items of the Scale