Although revisions made from the WAIS-R to the WAIS-III improved the floor of the test to make it more appropriate for the assessment of adults with mental retardation, many mentally retarded samples still perform at the floor-level on the cognitively complex tasks of the WAIS-III. The WAIS-III's Verbal IQ scale and Verbal Comprehension index are both heavily loaded with questions that tap school-learned, crystallized abilities. Many schools place individuals with mental retardation in a "vocational-track" rather than an "academic-track" curriculum, which, in effect, makes the educational background of individuals with mild mental retardation quite different from that of nondisabled individuals. Because of the discrepancies in educational experience of individuals with and without mental retardation, Verbal subtests may not provide the most helpful data in terms of understanding cognitive processes to make appropriate recommendations. To better understand how a person with mental retardation can function adaptively in society, WAIS-III scores can be supplemented with a test that measures one's ability to apply crystallized knowledge to everyday situations, namely the Kaufman Functional Academic Skills Test (K-FAST; Kaufman & Kaufman, 1994a) for ages 15-85+ (see Chapter 15). A measure such as the Vineland Adaptive Behavior Scales (Sparrow, Balla, Cichetti, 1984a, 1984b) is necessary to provide additional information about other domains of adaptive functioning including communication, daily living skills, and socialization.
The most common use of intellectual assessment for adolescents with mental retardation in school is to determine the need for placement in special education classes. For adults and older adolescents with mental retardation, intelligence is assessed to determine eligibility for benefits, to determine competence or incompetence in handling themselves, to monitor functioning, and to assess employability or unemployability (Lindemann & Matarazzo, 1984). Intelligence tests are useful as part of vocational planning for adolescents and adults with mental retardation (Capps, Levinson, & Hohenshil, 1985). Overall intellectual functioning is assessed to determine the level to which a person with mental retardation might progress in an occupation. Specific intellectual strengths and weaknesses are evaluated to determine the potential to meet the various demands of a job (e.g., visual-spatial skills, verbal skills, memory). The research on IQ, specifically Wechsler IQ, has indicated that there is not one simple pattern of performance on IQ tests that is consistent across individuals with mental retardation. Thus, without examination of an individual's profile, assumptions about the functioning of an individual with mental retardation cannot be made on the basis of what is known from studies using group data. In addition, although many think that adaptive behavior is equivalent to cognitive functioning (Coulter, 1980), this assumption is not true. Many professionals who work with adolescents and adults with mental retardation often expect those with low intelligence to have low adaptive behavior and vice versa. Although adaptive behavior and cognitive functioning are obviously related, the conceptualization and measurement of the two constructs differ in several respects (Meyers, Nihira, & Zetlin, 1979). Cognitive functioning is usually conceptualized as a thought process, while adaptive behavior emphasizes everyday behavior. Tests of cognitive functioning are intended to measure optimal maximum performance, or potential, while adaptive behavior scales measure typical performance. Intelligence is assumed to be stable, while adaptive behavior is assumed to be modifiable. Thus, because of the differences between intelligence and adaptive behavior, the IQ profile of an individual should not be examined without the coinciding data from adaptive behavior measures. An
IQ profile is not sufficient to understand a person's vocational or educational needs.
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Whenever a doctor informs the parents that their child is suffering with Autism, the first & foremost question that is thrown over him is - How did it happen? How did my child get this disease? Well, there is no definite answer to what are the exact causes of Autism.