A framework for understanding the etiology of organizational behavior is presented. The framework is based on theory and research from interactional psychology, vocational psychology, I/O psychology, and organizational theory. The framework proposes that organizations are functions of the kinds of people they contain and, further, that the people there are functions of an attraction-selection-attrition (ASA) cycle. The ASA cycle is proposed as an alternative model for understanding organizations and the causes of the structures, processes, and technology of organizations. First, the ASA framework is developed through a series of propositions. Then some implications of the model are outlined, including (1) the difficulty of bringing about change in organizations, (2) the utility of personality and interest measures for understanding organizational behavior, (3) the genesis of organizational climate and culture, (4) the importance of recruitment, and (5) the need for person-based theories of leadership and job attitudes. It is concluded that contemporary I/O psychology is overly dominated by situationist theories of the behavior of organizations and the people in them.