Article summary with Social categorization and ambiguity by Hugenberg & Bodenhausen - 2004

People argue that human faces have been shaped by selection (Darwin) to serve as a communication medium. One can ‘read’ the internal emotions of another person. The researchers of this study argue that emotional expressions may also influence the social category to which somebody is assigned.

Sometimes people can be easily assigned to certain groups. Usually you recognize in which group a person fits best. Sometimes, however, some stigmatised social identities can be concealed, like homosexuality. Race can also be ambiguous. There are different skin colours, eye colours and hair colour and they are not perfect markers of race. The stereotype of African Americans includes hostility. Somebody with an ambiguous identity (is he black or is he white?) will be more likely to be categorized as an African American when he displays a hostile facial expression than when he displays a happy one. This is what the researchers of the study propose. They also think that the extent to which stereotypes will affect categorization depends on the level of prejudice. People who are high on prejudice will be more likely to activate and apply stereotypic information.

In study 1 participants got to see racially ambiguous faces on the computer and they were asked to categorize each face as either Caucasian or African American. Each face was presented twice, once with an angry expression and once with a happy expression. They also completed some questionnaires to measure their racial attitudes. The results supported the hypothesis: high-prejudiced people were more likely to rate an ambiguous face as African American when this face was angry. The relationship between prejudice and categorization was stronger for angry than for happy faces.