This is the first comprehensive view of the work of scholars in several different disciplines contributing to the development of the psychology of science. This new field of inquiry is a systematic elaboration and application of psychological concepts and methods to clarify the nature of the scientific enterprise. While the psychology of science overlaps the philosophy, history, and sociology of science in important ways, its predominant focus is on individuals and small groups, rather than broad social institutions and concepts. The introduction surveys the field and traces its evolution in a historical context. Several contributors address epistemological issues raised by the psychology of science. Subsequent chapters discuss developments in the cognitive psychology of science, scientific theory, and the influence of social relationships on scientists’ work. The conclusion proposes an agenda for further progress in this new approach to understanding science.