The 1977 revision of the American Association on Mental Deficiency (AAMD) definition of mental retardation classified as severely retarded those individuals who have I.Q. scores or estimates of less than 39; four standard deviations below the norm (Grossman, 1977). Profound retardation involves I.Q. estimates on the Wechsler scales of 24 or less; five standard deviations below the norm. For convenience and relative ease of communication between professionals, the defining characteristics of severe/profound (S/P) retardation are often left as such. However, as the AAMD definition also includes a component of “adaptive behavior”, and in an attempt to clarify the characteristics of such persons to readers, we would refer to a set of behaviors suggested by Tawney (1977, p.13), describing the functional levels of persons with S/P handicaps. These include the following:

little or absence of vocal behavior;

little motor gestural behavior;

limited self-help skills;

inconsistent or absent bowel or bladder control;

no obtained score on standardized tests because none were administered or because these persons were untestable;

little social interaction with others;

inability to follow simple directions;

absence of reciprocal social reinforcement of people in their environment;

stereotyped behaviors;

disruptive social behavior;

low rates of behavior generally called “constructive play behavior”; and,

attendant multiple handicaps.