Organizational scholars now acknowledge the relevance of emotions in virtually every aspect of organizational life, including negotiations and conflict resolution. Integrating negotiation phase model theory with social functional models of emotion, we test hypotheses about the development of emotions in negotiations and their effects on the degree of economic (in)equity of the counterpart's subsequent offer during the actual negotiation process. By comparing stalemate dyads with efficient settlement dyads, the study identifies emotional dynamics that characterize successful as opposed to unsuccessful negotiations. Results show that observed differences are primarily the result of impasse dyads spiraling into a negative emotional climate rather than efficient settlement dyads having overall higher levels of positive emotions or increasing them throughout the negotiation process. As predicted by social functional models, the study further confirms that emotions are not only a reaction to the economic (un)fairness of a proposed offer, but their display also influences the payoff (in)equity of the counterpart's subsequent offer. Whether a specific emotional expression increases or decreases the economic fairness of the counterpart's subsequent offer, however, differs across negotiation phases and between dyads that reached an agreement or not. Furthermore, the results show distinct differences between emotions that address individual goal realization in negotiations and emotions that focus on the