The first part of this paper traces a short history of the psychological study of negotiation. Although negotiation was an active research topic within social psychology in the 1960s and 1970s, in the 1980s, the behavioral decision perspective dominated. The 1990s has witnessed a rebirth of social factors in the psychological study of negotiation, including social relationships, egocentrism, motivated illusions, and emotion. The second part of this paper reviews five emerging research areas, each of which provides useful insight into how negotiators subjectively understand the negotiation: (a) mental models in negotiation; (b) how concerns of ethics, fairness, and values define the rules of the game being played; (c) how the selection of a communication medium impacts the way the game is played; (d) how cross-cultural issues in perception and behavior affect the negotiation game; and (e) how negotiators organize and simplify their understandings of the negotiation game when more than two actors are involved.