Learning theory, intelligence, and mental development.

The current state of experimental research on mental retardation was considered from a historical perspective. The early position that defined intelligence as the ability to learn was presented. Subsequent refinements were traced as intelligence was related first to stages and, subsequently, to subprocesses of learning. Research on learning in retarded persons, which mainly dates from the late 1950s, took little account of this history. The methodological errors that flawed much modern mental retardation research were made explicit. Attempts to isolate the roles of MA and of intelligence were reviewed. It was shown that with growing understanding sophisticated designs emerged. Kappauf's three-dimensional model relating performance to IQ and CA was discussed and some models of retardation presented. Research on the development of intelligence was related to these models and to the design of intervention strategies.