Effects of approach and withdrawal motivation on interactive economic decisions

distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Although recent economic models of human decision making have recognised the role of emotion as an important biasing factor, the impact of incidental emotion on decisions has remained poorly explored. To address this question, we jointly explored the role of emotional valence (i.e., positive vs. negative) and motivational direction (i.e., approach vs. avoidance) on performance in a well-known economic task, the Ultimatum Game. Participants had to either accept or reject monetary offers from other players, offers that vary in their degree of unfairness. A main effect of motivational direction, but not valence, was observed, with withdrawal-based emotion (disgust and serenity) prompting more rejections relative to approach-based emotion (anger and amusement) and a neutral state. These results further confirm that subtle incidental moods can bias decision making, and suggest that motivational state may be a useful framework to study such decisions. Implications with regard to emotion, cognitive neuroscience, and clinical psychology are discussed.