West German research on children's interests is described, with emphasis on a 3-year longitudinal study of 12 children, aged 3 to 7. Two main lines of interest research are identified: (1) research activities rooted in the tradition of differential psychology emphasizing vocational interests, traits, and attitudes; and (2) research based on a new educationally oriented theory of interest, which defines interest as specific form of a relationship between a person and an object from the environment (PO). The PO-relationship involves internal and external actions, as well as an enduring disposition towards an object. Three research approaches include the formation of persistance and selectivity in interest development; specific interest objects such as literature and academic subjects; and ontogenetic development of interests. The longitudinal study collected data about the object-related activities and social behavior of young children. Results indicated common PO-relationships involving role playing, tinkering, painting, and construction games. There were marked differences in their object preference structure (one or two highly preferred objects versus several equally-preferred ones). Most PO-relationships were more characterized by an activity type than a specific object type. Both the educational and social environments influenced the development of PO-relationships. (GDC)