People often mistake prejudice for a bias. Read the article, "Is Prejudice a Bias?" McGuire asserts the two are different.
Applied scientists say prejudice is a bias. Unfortunately, many give into broad definitions, outlining its scope. Prejudice is an affective component like bias from which specific modes of thoughts and emotions occur, unjustly. These modes often form when a group or member attempts to justify with considerable thought an unacceptable emotion. We mistakenly call these modes of unjust reasoning biases.
By definition, prejudice is an unjustified negative attitude toward a culture, group, or member due to arbitrary reasons. Such reasons include having a strong dislike for an individual’s ascribed identity and, more often, membership in a particular group. As a modality, prejudiced reasoning will frequently cause unfavorable thoughts and emotions toward stranger and others. The result is an unjustified, negative attitude. Bias, on the other hand, is what we call a natural tendency. That is, biases are modes that frequently influence our thoughts and emotions in favor of one person over another. Both prejudice and bias are unjustified, thus influence us, unfairly. Hence, modes are what we call natural prejudice tendencies because prejudiced and biased reasoning will frequently prevent objective considerations of another. Each reflects the individual’s beliefs, opinions, ideas, and values in the scheme of culture.
Consider this example. You highly value your relationship with In Su. However, it is based on the cultural stereotype Chinese make great marshal art warriors. In this case, scientists would call your opinion of her positive prejudice. Why? You have based your understanding of In Su on a generalization about her group membership. In addition, you favor In Su for her cultural characteristics. Similarly race psychologists, and researchers adept at understanding the intimacies of intergroup behavior, would call your mode of thinking a natural prejudiced tendency. How come, you ask? You have developed from oversimplified ideas of China, a tendency to assign Chinese positive traits. They would argue, to whatever extent, having an oversimplified idea of Chinese culture, alone, does not constitute prejudice. That prejudgment of a culture, group, or member reflects an error in value judgment. In this case, your tendency to judge all Chinese as sharing in the same cultural characteristics is misleading. Therefore, your misunderstanding of Chinese and their culture is biased, thus a problem of perception. That is, while prejudice, positive or negative, is a problem of categorization and judgment, bias is a problem of perception and judgment. Before you decide whether prejudice is a bias, consider two important factors: (1) Prejudice has connotations for people invoked by their conforming beliefs. It also presupposes other beliefs we would more formally call racism. (2) Bias is a problem of perception and judgment whereby people develop the idea of human categories from which specific and often wrongful conclusions are reached.