This paper examines institutional variations in the factors that influence scientists in their choice and persistence in an area of research. More specifically, we study the problem choice behavior of early and late entrants in an emerging field. Early entrants are defined as those scientists who initiate and continue working in a field before it is widely perceived as significant or even legitimate by their peers. Evidence is presented from an international survey of more than 700 scientists working in the field of neural networks. Elaborating on previous results, which find that early entrants differ from late entrants in both their motivations to enter and their intentions to remain in the field, this study suggests that it is academic scientists who merit special distinction. In general, compared with other scientists, early entrants in academia are more deeply influenced by the intrinsic intellectual appeal of the field and are less influenced by the social dynamics of the research community. No difference is found between early and late entrants who are employed in commercial institutions.