What is the mission of developmental psychology? What is its role in history and society? Traditional philosophical models asserted the doctrine of the unity of science, with the natural sciences providing the model for all scientific endeavors. In this view, conceptual definitions, procedures, and methodologies of the “less mature” human sciences ought to be patterned after those of experimental physics, as a “mature” science. In the Age of Theory, Sigmund Koch's (1964) term for the period of theoretical behaviorism spanning the 1930s and 1940s, a vision of psychology as an “immature physics” was set forth.

Today, psychology continues to use many concepts, procedures, and definitions of “good science” borrowed from the natural sciences, although many aspects of developmental research are unlike those of experimental physics. The full range of children's thought and behavior is not captured easily by simple laws, numerical equations, or mathematical models. What, then, holds the natural-science model of developmental psychology in place? One factor is a set of institutional structures built up during the great growth period immediately after World War II, in the 1940s and the 1950s. During this era, much of the cooperative architecture of contemporary science was established – granting agencies, journals, norms and values of graduate education, definitions of appropriate methodology, and so forth. This institutional architecture implicitly enforces a traditional view of what science is and ought to be.