ORGANIZATIONAL BEHAVIOR AND HUMAN DECISION PROCESSES 52, 276-291 (1992) Mood Effects on Subjective Probability Assessment WILLIAM F. WRIGHT University of California, Irvine AND GORDON H. BOWER Stanford University A person’s mood may directly affect a judgment of the uncertainty of a future event. Subjective probabilities were reported by subjects in a happy, neutral, or sad mood for personal and nonpersonal events. Two moods were induced by having the subject focus on particularly happy and sad personal experiences. Large, consistent mood effects are indicated. Relative to control subjects, happy people are “optimistic; ” i.e., they report higher probabilities for positive events and lower probabilities for negative events. Conversely, sad people are “pessimistic,” providing lower (higher) probabilities for posi- tive (negative) events. Mood-state-dependent retrieval of information is indi- cated. Q 1992 Academic press. IIIC. Research on the impact of affect on cognition is a contemporary topic in cognitive (Blaney, 1986;Gilligan & Bower, 1986),social (Clarke, 1982; Clark & Isen, 1982),and organizational (George, 1989) psychology. Emo- tions can have a substantial impact on the retrieval of knowledge from memory (Gilligan & Bower, 1984),and on the processing of information (Isen, Means, Patrick, & Nowicki, 1982;Clark, 1982).For example, sub- jects in a sad mood will learn or recall more negative than positive ma- terial (Blaney, 1986). A basic premise of rational decision-making is logical, consistent, and unbiased understanding of environmental uncertainty, and choice of the optimal decision. Subjective probabilities (SPs hereafter) are elicited to quantify subjective uncertainty (Wallsten & Budescu, 1983), to provide information for formal decision models (Howard, 1988;Raiffa, 1968),and to study information integration and evaluate the quality of judgments (Tversky & Kahneman, 1974). Mood effects may exist in decision-making contexts (e.g., Isen & Geva, The contribution of Randy Geflerman to this work is gratefully acknowledged. Address correspondence and reprint requests to William Wright, Graduate School of Management, University of California, Irvine, CA 92717-3125. 276 0749-5978192 $5.00 Copyright 0 1992 by Academic Press, Inc. All rights of reproduction in any form reserved.