Developmental delays or disabilities encompasses a variety of individual differences and pathological conditions. Most developmental problems become apparent in the school age child as delays are found in language and speech development.
Statistics demonstrate a lack of clear-cut distinction between developmentally delayed or disabled and learning disabled populations. Developmental delays or developmental disabilities involve the functions of the central nervous system. The spectrum of these disabilities includes cerebral palsy, mental retardation, epilepsy, language disorders, and infantile autism. A 1984 survey of 41 university centers for developmentally disabled identified the following groups: mental retardation (28 percent), specific learning disability (16 percent), general underachievement (12 percent), behavior disorders (8 percent), speech impaired (7 percent), severely emotionally disturbed (6 percent), orthopedically impaired (4 percent), sensory impaired (3 percent), autistic (2 percent), and other (14 percent) (Westman, 1990).
The term learning disability becomes vague and controversial when applied to the individual child. Most learning disabilities are relative rather than absolute; individual differences in functions of the brain rather than pathological conditions need to be considered. The term learning disability became popular in 1963 with the organization of the Association for Children with Learning Disabilities. Since that time there have been efforts to both include and exclude the mentally retarded from the group of the learning disabled; this resulted in problems since 85 percent of the mentally retarded are mildly disabled. Thus the definition of learning disability implied the presence of central nervous system dysfunction, responsible for suboptimal academic learning. This learning was in specific academic subjects rather than in a general ability to learn. This inadequate definition di...