Critical Periods, Early Experience, and the Development of Intelligence

The concept of intelligence as developing processes and structures (Hunt, 1961; Piaget, 1952) is presently making some promising contributions to the search for the optimal method of and approach to learning. This view is new in that it focuses on a hierarchical development of cognitive structures and processes which are dependent upon organism-environment interaction whereas traditionally, intelligence has been viewed as a function of heredity with physical growth and maturation insuring its automatic development (Gesell, 1954). The new approach stands on the belief that cognitive structures and processes develop in a definite and ordered fashion, though not at a constant rate. The beginning of the time of the organization of processes and structures is a critical period (CP) since organism-environment interaction may influence the organization very strikeingly at this time (Scott, 1968). The end of the organization and development of structures and processes is set off by behavioral landmarks which occur due to the just acquired process or structure. Landmarks seem to occur in a fixed order, hence they can be used as one meaningful measure of intelligence (Hunt, 1961). Further, since, according to the new view, the development of intelligence depends upon organism-environment interaction, it should be possible to enhance development by manipulation of the environment during CPs