This paper is concerned with the way we understand and investigate the relationship between human functioning and social setting. The central argument draws on the work of Bernstein and Vygotsky. A novel approach to the study of the mutual shaping of human action and institutional settings is developed and an empirical example of its application is presented and discussed. The research reported here is drawn from a four-year ESRC-TLRP-funded study of professional learning in and for interagency working in children's services in England. (Contains 2 notes, 2 tables, and 4 figures.)