This study surveyed ninth- and eleventh-graders' evaluations of social exclusion based on social group membership. Responses indicated that participants found exclusion less wrong than denying resources, and used fewer moral and more conventional reasons to justify judgments. Participants relied on their group knowledge or stereotypes in evaluating ambiguous situations and on personal knowledge in evaluating nonambiguous situations. Age and sex differences were found in evaluations, reasoning, and stereotype use. (Author/KB)