Participants were led to expect either cooperation or conflict, and then performed K. Duncker's (1945) functional-fixedness task (Experiment 1) or E. Rosen's (1975) categorization task (Experiment 2). Those who expected cooperation, compared with those who expected conflict, were more likely to solve Duncker's task and used categories more inclusively, that is, rated low-prototypic exemplars of a category as better members of the category. In Experiment 3, the direct experience of cooperation and conflict had the same effect on categorization. In Experiment 4, participants were classified as having cooperative, competitive, or individualistic social values, and were led to expect either cooperation, conflict, or neither in a control. In the control, cooperators used categories more inclusively than competitors or individualists. Competitors used categories least inclusively in me conflict condition; in the cooperation condition, they used categories most inclusively. These results are interpreted in terms of the possible mediating role of cognitive organization in individual and intergroup conflict resolution.Successful conflict resolution often requires that the disputants develop novel alternatives, consider new perspectives, and entertain a fresh outlook on the issues. However, conflict situations can affect motivations, cognitions, and behavior in a way that reduces the likelihood of mutually acceptable agreement (Deutsch, 1969(Deutsch, , 1994Pruitt, 1981;Pruitt & Rubin, 1986). Conflict can produce an aversive drive-like arousal state (Steigleder, Weiss, Balling, Wenninger, & Lombardo, 1980), and it can elicit a counter-empathy response, where a smile on an opponent's face elicits a grimace and vice versa (Lanzetta & Englis, 1989). In conflict resolution, it is a challenge to mediators and other intervenors to foster creativity and exchanges of information in an effort to help disputants develop integrative, win-win agreements.There is indirect evidence that social conflict can produce rigid thinking, which entails restricted judgment, reduced complexity, and an inability to consider alternative perspectives