Prejudice and discrimination by members of one group against members of another group is ubiquitous. This collaborative research project aims to better understand the conditions under which emotions felt toward other groups can exacerbate or reduce prejudice and discrimination. Research has already shown that antipathy and intolerance between groups is often driven by specific emotions (such as anger and resentment, fear and anxiety, sympathy, or guilt) that are aroused when people encounter members of other groups. The two sets of studies in this proposal focus on two important antecedents of specific emotions directed at other groups. In the first set of studies changes in people's perceived group membership is examined. The impact of these changes in categorization on emotions is assessed as well as the potential effects of an individual's emotional state on the categorization process itself. The second set of studies examines personal contact with an individual member of another group as a way of understanding the specific emotions that contribute to a positive outcome, and how these emotions translate into overt behavior in encounters between groups. Taken together, findings from this research will show how preconditions influence emotions which then translate into prejudice and behavior, and how this sequence might be altered or short-circuited. By showing when and how emotions toward other groups can exacerbate or reduce prejudice and discrimination, these research results may illuminate ways of reducing these important social problems.