Behavioral research on negotiation in recent years has been dominated by the decision-making research paradigm, which accords a relatively narrow role to emotions. Decision-making researchers have considered emotions primarily in terms of how an individual’s positive or negative affect impacts, and usually impedes, his or her information processing. Drawing on recent advances in psychology and other fields, we propose an alternative perspective that highlights more social and more functional aspects of emotion in negotiation. We conceptualize emotions as interpersonal communication systems that help individuals navigate the basic problems that arise in dyad and group relations. Emotions are evoked by these specific relational problems and one person’s emotional expression impacts other persons, often with the consequence of resolving the relational problem. From this social functional perspective, we draw insights concerning: (a) the influence of specific emotions upon negotiation-related cognition and behavior; (b) the transitions between qualitatively different phases within negotiations; and (c) the ways in which negotiations are shaped by contextual variables such as culture and communication media.This attached version is a preprint version of the article. The final version may be found here.