Over a decade ago, Pat Langley and I predicted that an important source for cognitive models of science would come from "the developmental psychology of socialization," which studies the way that children become part of their culture (Shrager & Langley, 1990). We suggested that "insights into this process may provide hypotheses about the paths through which graduate students and junior scientists become members of their scientific community-mastering the ways of thinking, operating, and communicating that constitute the institution of science" (pp. 19-20). An interesting methodological refinement of this proposal can be found in Tanya Lohrmann's fascinating participant-observer study of modern witchcraft in England (Lohrmann, 1989). Lohrmann joined a coven, participating in the rituals, and reported on the process of becoming a neo-pagan witch. Others have engaged in participant-observer studies of science, and even specifically of molecular biology (e.g., Latour & Woolgar, 1979/1986), but they have not, to my knowledge, done so with the goal of observing the process of

becoming molecular biologists. In this chapter I present preliminary results from the first study of this kind.