Bias is defined as distortion of judgment or perception of a person or group based on the person’s or group’s race, religion, ethnicity, gender, age, sexual orientation, heritage, or ancestry, resulting in differential treatment in clinical work, diagnosis, and testing. The term bias has been used interchangeably with prejudice, specifically related to holding a distinct point of view or ideology. Stereotypes contribute to biases and negative perceptions of people who are different than oneself or perceived as an “outgroup.” Concurrently, individuals may use stereotypes to form biases and predict or explain behavior of members of an outgroup, although it is possible for individuals to hold biases and believe a stereotype but not apply it to certain individuals from that group.

A recent decrease in biases may be attributed to social norms that promulgate politically correct attitudes and behaviors rooted in conformity rather than an authentic reduction of prejudice. Subsequently, outright expressions of bias have become less acceptable causing some people to appear unbiased while holding biased viewpoints and creating a close link between internalizing and expressing personal bias and social acceptability.

Individuals typically are exposed to family bias during early childhood and learn to disparage those who are different from them. During later years, children learn biases from peer groups, surrounding communities, and the mass media when they are exposed to overrepresentations of negative stereotypes and gross generalizations of groups such as ethnic and racial minorities. Bias also may occur from direct experience or conflict between one’s own group and other groups that may cultivate irrational assumptions and attitudes.

Theories of bias and prejudice have historically emerged in response to circumstances and events, causing shifting theories about the origin of bias that parallel particular circumstances at a given time. A brief historical summary of racial bias provides an excellent framework for understanding current biases. During the 1920s, racial differences became a prominent social theme so theories of prejudice focused on understanding racial differences and antipathies. Race theories looked at inferiorities of outgroups and discussed the backwardness of inferior races in terms of lacking intelligence and evolutionary backwardness, which, in the 1930s, shifted dramatically away from inferiority of outgroups and the superiority of Whites to causes of bias. Social scientists began examining attitudes and beliefs held within the dominant European American group toward other racial and ethnic minority groups and the unjustness and flaws of these biases, leading to an emphasis of White prejudice rather than ethnic and racial minority inferiority.

The 1940s evolved into an era of understanding about White racism. The concepts of unconscious psychological processes and defense mechanisms were introduced as roots of prejudice, exploring psychodynamic processes and bias. The 1950s shifted away from intrapsychic processes and an individual focus presenting prejudice as a by-product of personality development and social conditioning, related to Nazi racial ideology and personality traits conducive to developing biases. The next 2 decades deemphasized individual bias, focusing on group conformity and social norms as the cause of bias. At the same time a growing civil rights movement and heightened concern with other social and political issues led to emphasizing social conditions as underlying roots to prejudice, a view that continued through the 1980s and beyond.

Bias in testing and clinical assessment, as well as treatment and service delivery, also presents issues of concern in psychology. Test disparities between racial and ethnic groups, social strata, genders, and geographic regions raise serious questions about the standardization and construction of test instruments that are culturally unbiased. Despite attempts by the Diagnostic and Statistical Manual of Mental Disorders to promote consistency and reduce bias, critics argue that diagnostic biases continue to result in overdiagnosis, underdiagnosis, and misdiagnosis and that testing and diagnosis perpetuate inequality, discrimination, and oppression rather than promote fair assessment and diagnosis. The result of clinical biases in testing, assessment, and treatment is culturally insensitive services and client dropout.

There are a number of theories that have been developed to explain various types of bias and prejudice. One is the justification-suppression model which explained holding back on expressing prejudice because of social norms that suppress the public expression of certain biases. When guilt or shame is absent, it is easier to justify expressing biases publicly. Another similar theory, the self-presentational theory, explains how individuals privately display prejudice while not sharing their views publicly unless the prejudicial values are acceptable as the norm. Aversive racism theory describes how racist beliefs may be repressed and denied and become unconscious, causing individuals to share their biases publicly only in situations that allow them to rationalize their unconscious values. The social dominance theory argues that there are group-based hierarchies with dominant and subordinate groups within society. Dominant groups have power over other groups and enjoy disproportionate privilege; individuals in dominant groups then support and maintain their hierarchical position. The personality model of prejudice emphasizes individual traits that are immutable across situations as the cause of prejudice. A variation of this model is the person X situation model, which asserts that situational variables, such as power or social status, interact with personality to develop prejudice. Also emphasizing the social context is the group socialization model, whereby the groups determine personal beliefs and the expression of bias, and the group normative theory, which looks at the development of prejudicial norms and social pressure for conformity in social groups.

Within these different theories, individuals are motivated to adopt certain beliefs and attitudes and frequently adopt prejudicial views to meet personal needs. Personal motivations may increase stereotyping behavior and justify the bias, generating a “blaming the victim” mentality whereby people get what they deserve.

Bias serves many purposes while negatively impacting people who are targets of discrimination and prejudice and negatively influencing counseling practice, testing, and diagnosis. Bias helps predict stereotypical behaviors from people different than oneself while solidifying negative values and inaccurate stereotypes. Bias assists in perpetuating stereotypes and heightens sensitivity to those values in ways that can be socially supported and highly destructive. Furthermore, bias explains and normalizes behavior toward members of outgroups, reaffirming one’s “rightness and worthiness,” and doesn’t take into account differences that affect testing, service delivery, and counseling. The cultivation and perpetuation of “we” versus “they,” ingroup versus outgroup mentality, and a right versus wrong way of thinking diminishes tolerance, openness, and respect toward diversity and differences and effective counseling.


  1. Dion, K. (2002). The social psychology of perceived prejudice and discrimination. Canadian Psychology, 43(1), 1-10.
  2. Gaines, S. O., & Reed, E. S. (1995). Prejudice: From Allport to DuBois. American Psychologist, 50(2), 96-103.

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