Agile software development is often, but not always, associated with the term dasiaproject chemistry,psila or the positive team climate that can contribute to high performance. A qualitative study involving 22 participants in agile teams sought to explore this connection, and answer the question: what aspects of agile software development are related to team cohesion? The following is a discussion of participant experiences as seen through a socio-psychological lens. It draws from social-identity theory and socio-psychological literature to explain, not only how, but why agile methodologies support teamwork and collective progress. Agile practices are shown to produce a socio-psychological environment of high-performance, with many of the practical benefits of agile practices being supported and mediated by social and personal concerns.