DESCRIPTION (Applicant's Abstract): Seventeen studies are proposed to examine the role that various cognitive, perceptual, motivational, and social processes play in creating and perpetuating social conflict, and in thwarting dispute resolution. One set of studies proceeds from an analysis of "naive realism" (i.e., the belief that one's own perceptions and beliefs represent an accurate portrayal of "objective reality") to derive and consider two related phenomena: the tendency to overestimate the extremity and ideological consistency of partisans, and the tendency to see hostile bias in the efforts of mediators and other "third parties." A second set of studies focuses on the tendency for partisans to "reactively" devalue comprises and concessions offered by the "other side" (i.e., the tendency to decrease one's liking for compromises or concessions that have been explicit offered, relative to alternatives that have not been offered). A third set of studies examines three other dispute-resolution barriers: i.e., the pursuit of equity, the unwillingness to bear losses in order to achieve gains, and the dissonance engendered by previous negotiation failures. A final set of studies examines the effectiveness of a number of strategies hypothesized by our conceptual analyses to reduce or eliminate various conflict-resolution barriers. The research strategy followed in these studies generally involves three related components: first, demonstrating phenomena and exploring parameters; second, investigating underlying processes; and third, testing the success of various "interventions" that our conceptual analyses (and real-world experiences) suggest should attenuate the phenomena in question. These studies speak to classic theoretical issues concerning the interplay of cognitive, perceptual, and motivational processes-e.g., assimilation versus contrast, dissonance versus reactance, shifts in interpretation versus shifts in preference or priority-in influencing human judgment and decision -making. At the same time, they promise significant dividends for practitioners who seek to understand and ameliorate the stalemates, and spirals of hostility and distrust, that threaten individual mental health and jeopardize relationships among individuals, groups, and even nations.