Social dominance orientation (SDO) is a psychological orientation that predicts social and political attitudes. It is a widely applied Social Psychological scale. SDO is conceptualised as a measure of individual differences in levels of group-based discrimination and domination; that is, it is a measure of an individual's preference for hierarchy within any social system. The concept of SDO as a measurable individual difference is a product of Social Dominance Theory.
SDO has been measured by a series of scales refined over time, all of which contain a balance of pro- and contra-trait statements or phrases. A 7-point Likert scale is used for each item; participants rate their agreement or disagreement with the statements from 1 (strongly disagree) to 7 (strongly agree). Most of the research was conducted with the SDO-5 (a 14-point scale) and SDO-6.
- Some groups of people are simply inferior to other groups.
- In getting what you want, it is sometimes necessary to use force against other groups.
- It’s OK if some groups have more of a chance in life than others.
- To get ahead in life, it is sometimes necessary to step on other groups.
- If certain groups stayed in their place, we would have fewer problems.
- It’s probably a good thing that certain groups are at the top and other groups are at the bottom.
- Inferior groups should stay in their place.
- Sometimes other groups must be kept in their place.
- It would be good if groups could be equal.
- Group equality should be our ideal.
- All groups should be given an equal chance in life.
- We should do what we can to equalize conditions for different groups.
- Increased social equality.
- We would have fewer problems if we treated people more equally.
- We should strive to make incomes as equal as possible.
- No group should dominate in society.
Keying is reversed on questions 9 through 16, to control for yea-saying.
Social dominance theory
SDO was first proposed by Jim Sidanius and Felicia Pratto as part of their Social Dominance Theory (SDT). SDO is the key measurable component of SDT that is specific to it.
SDT begins with the empirical observation that surplus-producing social systems have a threefold group-based hierarchy structure: age-based, gender-based and “arbitrary set-based,” which can include race, class, sexual orientation, caste, ethnicity, religious affiliation, etc. Age-based hierarchies invariably give more power to adults and middle-age people than children and younger adults, and gender-based hierarchies invariably grant more power to men than women, but arbitrary-set hierarchies—though quite resilient—are truly arbitrary.
SDT is based on three primary assumptions:
1. While age- and gender-based hierarchies will tend to exist within all social systems, arbitrary-set systems of social hierarchy will invariably emerge within social systems producing sustainable economic surpluses.
2. Most forms of group conflict and oppression (e.g., racism, homophobia, ethnocentrisim, sexism, nationalism, classicism, regionalism) can be regarded as different manifestations of the same basic human predisposition to form group-based hierarchies.
3. Human social systems are subject to the counterbalancing influences of hierarchy-enhancing (HE) forces, producing and maintaining ever higher levels of group-based social inequality, and hierarchy-attenuating (HA) forces, producing greater levels of group-based social equality.
SDO is the individual attitudinal aspect of SDT. It is influenced by group status, gender (women score lower on SDO), socialization, and temperament. In turn, it influences support for HE and HA "legitimating myths," defined as “values, attitudes, beliefs, causal attributions and ideologies” that in turn justify social institutions and practices that either enhance or attenuate group hierarchy.
Group-based and individual dominance
Robert Altemeyer construes SDO as a measure which includes aspects of personal dominance, so that high-SDO individuals will aspire to gain more power and climb the social ladder. Altemeyer's research suggested that high SDO scorers were competitive on a personal level (agreeing with items such as "Winning is more important than how you play the game") and were also quite Machiavellian (manipulative and amoral) agreeing with items such as "There really is no such thing as 'right and wrong'. It all boils down to what you can get away with."
These observations are clearly distinct from the core concept of SDO, as well as the content of the questions on the SDO. It seems intuitively obvious that there should be a large overlap between levels of group-based and personal dominance; and as such the SDO measure will reflect not only group-based dominance, but levels of interpersonal dominance as well. This is supported by Sidanius and Pratto's own evidence that high-SDO individuals tend to gravitate toward hierarchy-enhancing jobs and institutions, such as law enforcement, that are themselves hierarchically structured vis-a-vis individuals within them.
Early development of SDO
While the correlation of group status and gender to SDO has been empirically confirmed and measured, the impact of temperament and socialization remains more murky.
John Duckitt has suggested a model of attitude development for SDO, suggesting that unaffectionate socialisation in childhood causes a tough-minded attitude. According to Duckitt's model, people high in tough-minded personality are predisposed to view the world as a competitive place in which resource competition is zero-sum. A desire to compete, which fits with social dominance orientation, influences ingroup and outgroup attitudes.
Sidanius and Pratto propose that one mediating factor in SDO is androgens, noting primarily that males tend to have higher SDO scores than females, and are also observed to be more socially hierarchical. The proposed biological reason for this difference in dominance is increased levels of androgens, primarily testosterone. Male levels of testosterone are much higher than that of females. However, contemporary empirical studies  have refuted the thesis that testosterone levels correlate with aggression, and even that males are more aggressive or domineering than females, although they are more prone to physical violence.
Connection with Right Wing Authoritarianism
SDO has been deployed with the Right Wing Authoritarianism (RWA) scale. SDO correlates weakly with Right Wing Authoritarian (r ≈ .18) and together they predict to varying degrees many forms of prejudicial attitudes, such as sexist, racist, and heterosexist attitudes. SDO and RWA contribute in an additive rather than interactive way to prejudice (the interaction of SDO and RWA accounted, in one study, for an average of less than .001% variance in addition to their linear combination), that is the association between SDO and prejudice is similar regardless of a person's level of RWA, and vice versa. Little research has been done relating directly to behavior, however.
Correlation with Conservative Political Views
Felicia Pratto and her colleagues have found evidence that a high Social Dominance Orientation is strongly correlated with conservative political views, and opposition to programs and policies that aim to promote equality (such as affirmative action, laws advocating equal rights for homosexuals, women in combat, etc.).
There has been some debate within the psychology community on what the relation is between SDO and racism/sexism. One explanation suggests that opposition to programs that promote equality is based not on racism or sexism but on a "principled conservatism", that is, a "concern for equity, color-blindness, and genuine conservative values".
Some principled-conservatism theorists have suggested that racism and conservatism are independent, and only very weakly correlated among the highly educated, who truly understand the concepts of conservative values and attitudes. In an effort to examine the relationship between education, SDO, and racism, Sidanius and his colleagues asked approximately 4,600 Euro-Americans to complete a survey in which they were asked about their political and social attitudes, and their social dominance orientation was assessed. Results partially supported the principled-conservatism position, but also suggest several problems. Contrary to what these theorists would predict, correlations among SDO, political conservatism, and racism were strongest among the most educated, and weakest among the least educated. Sidanius and his colleagues hypothesized this was because conservatives tend to be more invested in the hierarchical structure of society and in maintaining the inequality of the status quo in society.
- Sidanius,Jim and Pratto, Felicia (2001). Social Dominance: An Intergroup Theory of Social Hierarchy and Oppression, Cambridge University Press
- Sibley, Chris G.; Robertson, Andrew; Wilson, Marc S. (2006). "Social Dominance Orientation and Right-Wing Authoritarianism: Additive and Interactive Effects". Political Psychology 27: 755. doi:10.1111/j.1467-9221.2006.00531.x.
- Pratto, Felicia; Sidanius, Jim; Stallworth, Lisa M.; Malle, Bertram F. (1994). "Social dominance orientation: A personality variable predicting social and political attitudes". Journal of Personality and Social Psychology 67: 741–763. doi:10.1037/0022-3522.214.171.1241.
- Sidanius, J; Pratto, F; Bobo, L (1996). "Racism, conservatism, affirmative action, and intellectual sophistication: A matter of principled conservatism or group dominance?" (PDF). Journal of Personality and Social Psychology 70 (3): 476–490. doi:10.1037/0022-35126.96.36.1996. http://www.wjh.harvard.edu/soc/faculty/bobo/pdf%20documents/Racism.pdf.