ABSTRACT
Definitions of mental retardation have “extra scientific” importance given that an individual so classified qualifies for specialized services and may also be denied certain rights under the law that are guaranteed to citizens of a society. Kuhlman (1924) wrote, “Definitions of Mental Deficiency have an extra scientific interest … they decide the fate of thousands of human beings every year and are intimately related to social welfare in general” (p. 58). Interest in; and debate over, definitions of mental retardation appear to have elevated since the American Association on Mental Deficiency 1 published its manual on terminology and classification (Heber, 1959; revised 1961). Although this definition was not endorsed by all in the field (see Clausen, 1967; Kidd, 1964), the AAMR definition of 1961 became the most widely used and influential definition of its day—influencing the wording of state-level education codes and legislation concerned with individuals with mental retardation.
