Mental retardation (MR) diagnosis has changed dramatically in recent years. Most notably, the IQ test score necessary for the diagnosis has dropped from one standard deviation below the mean (85) to two standard deviations below the mean (70). The business of IQ testing has become controversial. Early in their history, IQ tests were considered a large step forward in diagnostic procedure. In recent years many persons involved with the assessment of mental retardation have labeled IQ tests a step backward in diagnosis.
The current definition of mental retardation has three criteria: IQ test score of 70 or below; deficits in personal-social adaptive behaviors, and a manifestation during the developmental period (birth to age 18). Only the last criterion is clear-cut. If an individual sustains brain damage that leaves him or her developmentally disabled in adulthood, we do not apply the label mental retardation. The second criterion, deficits in personal-social adaptive behaviors, has gained in importance in assessment procedures since IQ tests have been deemed invalid and unreliable by some professionals. However, adaptive scales measure independence and social behaviors with a simple yes or no (present or absent) rating. The person completing the scale can be biased to report more or less success in personal-social adaptation. The definition of adaptive behavior is unclear. Adaptive scales may also be invalid and unreliable. What, then, is used to determine mental retardation?
A 1979 court case in California concluded that IQ tests were racially and culturally biased because disproportionate numbers of culturally diverse children had been mislabeled as mentally retarded and placed in segregated special classes in violation of PL 94-142. The judge ruled that California children must be assessed for intelligence without the use of existing IQ tests, and any future IQ tests must be approved by the courts before use. While most states still use IQ tests, mental retardation today is usually determined only after multiple assessments of adaptive behavior, cognitive processes, problem-solving strategies, observations of real-life behaviors, and histories of prenatal, neonatal, and early childhood health and development.
Mental retardation diagnosis has also been changed by reducing the use of arbitrary labels such as mild, moderate, severe, and profound based on IQ test scores. There are vast differences between children with mental retardation even if they score exactly the same on an IQ test. For example, one student with an IQ of 50 (formerly considered moderately retarded or "trainable'Vnot "educable") may learn to read, write, and find a skilled vocational job
Another student with an IQ of 50 may have difficulty completing even unskilled tasks and may drop out of school at age 16 with functional illiteracy. Mildly retarded individuals can usually profit from academic training and can learn to live alone or semi-independently. Severely retarded individuals can usually profit from training in self-help and communication, but they will probably need custodial care for life.
What causes mental retardation? For the majority of persons with MR, the exact cause(s) cannot be determined. Over one-half of all cases of mental retardation are suspected to be due to some biological factor(s) causing brain damage. Nearly 300 factors have been identified as risks that singly, or in combination, can alter brain functioning or destroy neurons. Prenatally, some risks include drugs, viruses, radiation, chromosomal defects, defective genes, maternal gestational disorders, and inadequate nutrition of mother. Neonatally, some risks include prematurity, low birth weight, trauma, infection, anoxia, metabolic and nutritional factors, and tumors. Early childhood risks include tumors, malnutrition, exposure to drugs or poisons, brain infections, head injuries, physical abuse, and psychiatric disorders. In addition to biological risk factors, some environmental conditions put infants and children at greater risk of developing mental retardation. It is usually impossible to pinpoint exactly what factor(s), singly or in combination, cause each child's unique type and degree of MR.
The Individuals with Disabilities Education Act, PL 94-142, and its amendments, require nondiscriminatory evaluations, zero reject, parental participation, individualized education programs, due process, least restrictive education, and transitional services for persons with mental retardation. As much as possible, everyone involved with the education of MR students should strive to establish the most normal life for them and teach them coping and adapting skills that are culturally appropriate. The earlier that MR infants and preschoolers can be identified and the earlier that they can be brought into special educational services, the easier it is to achieve a measure of "normalization" in their lives.
Early identification and treatment of mental retardation in infants and toddlers (age 0-5) is now mandated by PL 99-457. States are given incentives to establish not only preschool programs for MR children, but also to try to prevent MR through prenatal care, genetic counseling, and improved family planning. Preschool programs for MR children develop Individualized Family Service Plans (IFSPs) and provide parental education as well as early childhood remediation. Diet management, safety, education, socialization skills, and communication are included in preschool special services. Social services are provided long term for the MR child and his or her family.
Public schools develop Individualized Education Programs (lEPs) for every child with MR and update them annually. In addition to academic skills, the curriculum for MR students usually includes socialization and adaptive behaviors and prevocational and vocational skills. By high school the lEPs for students with MR usually include competitive employment training and community living skills (e.g., travel, personal maintenance, leisure, home-making).
Transitional services for MR students are now mandated by PL 101-476. Public schools must provide assistance for MR individuals as they move from school to employment and independent living until they reach age 21.
The first article in this unit discusses prevention of, and intervention for, MR caused by drug exposure. Selection two provides strategies for integrating MR students into regular education classes, and it presents both challenges and solutions.
The next article discusses training peer tutors to both help teach transitional skills to MR students in high school and to teach social interaction skills.
Looking Ahead: Challenge Questions
How can poor outcomes such as MR after prenatal drug exposure be avoided? How can the MR caused by drug exposure be ameliorated by intervention?
What solutions have been successfully pursued to meet the challenges of integrating MR students into supported regular classes?
Can social interaction training help peer tutors teach social as well as academic and job-related skills to students with MR?