“This article examines the behavioral dynamics at the interface between organizations in strategic partnerships called cause-based partnerships (CBPs). These are partnerships between a corporation and one or more nonprofit organizations that address social metaproblems such as environmental sustainability or social-justice challenges. Various a priori differences such as tasks, processes, and organizational cultures are expected to affect outcomes, but this article argues that a key determinant of successful CBP performance is behavioral dynamics at the interface between the partners. This article builds a framework for understanding these behavioral dynamics in terms of an emergent culture. Three scenarios — integration, reculturation, and separation — are described for how participants in CBPs continually negotiate a workable set of cultural practices among themselves. Examples are based on interviews with CBP managers. These explorations expand the basis for understanding CBP dynamics beyond those provided by static task, process, or common-culture explanations.”