What can psychology tell us about prejudice, discrimination, and racism?

Prejudice and racism are about real power, they're not just something that is in people's heads. Social issues like prejudice are complex and operate at many levels. At one level, issues of economics, political power, and domination are important. But individuals must perceive, interpret, and value differences in these "real-world" factors in order to act on them. Some psychologists have been interested in how people come to define real-world situations in terms of competition