Despite their distinct objects of study, the human behavioral sciences all include models of individual human behavior. Unity in the behavioral sciences requires that there be a common underlying model of individual human behavior, specialized and enriched to meet the particular needs of each discipline. Such unity does not exist, and cannot be easily attained, since the various disciplines have incompatible models and disparate research methodologies. Yet recent theoretical and empirical developments have created the conditions for unity in the behavioral (...) sciences, incorporating core principles from all fields, and based upon theoretical tools (game theory and the rational actor model) and data gathering techniques (experimental games in the laboratory and field) that transcend disciplinary boundaries. This article sketches a set of principles aimed at fostering such a unity. Key Words: behavioral science • game theory • experimental economics • rational actor model. (shrink)