Characteristics of Children with Mental Retardation

Buy this book »

Mental retardation means substantial limitations in age-appropriate intellectual and adaptive behavior. It is seldom a time-limited condition. Although many individuals with mental retardation make tremendous advancements in adaptive skills (some to the point of functioning independently and no longer being considered under any disability category), most are affected throughout their life span (Hawkins, Eklund, James & Foose, 2003).

Many children with mild retardation are not identified until they enter school and sometimes not until the second or third grade, when more difficult academic work is required. Most students with mild mental retardation master academic skills up to about the sixth-grade level and are able to learn job skills well enough to support themselves independently or semi-independently. Some adults who have been identified with mild mental retardation develop excellent social and communication skills and once they leave school are no longer recognized as having a disability.

Children with moderate retardation show significant delays in development during their preschool years. As they grow older, discrepancies in overall intellectual development and adaptive functioning generally grow wider between these children and age mates without disabilities. People with moderate mental retardation are more likely to have health and behavior problems than are individuals with mild retardation.

Individuals with severe and profound mental retardation are almost always identified at birth or shortly afterward. Most of these infants have significant central nervous system damage, and many have additional disabilities and/or health conditions. Although IQ scores can serve as the basis for differentiating severe and profound retardation from one another, the difference is primarily one of functional impairment.

Cognitive Functioning

Deficits in cognitive functioning and learning styles characteristic of individuals with mental retardation include poor memory, slow learning rates, attention problems, difficulty generalizing what they have learned, and lack of motivation.

Memory.  Students with mental retardation have difficulty remembering information. As would be expected, the more severe the cognitive impairment, the greater the deficits in memory. In particular, research has found that students with mental retardation have trouble retaining information in short-term memory (Bray, Fletcher, & Turner, 1997). Short-term memory, or working memory, is the ability to recall and use information that was encountered just a few seconds to a couple of hours earlier—for example, remembering a specific sequence of job tasks an employer stated just a few minutes earlier. Merrill (1990) reports that students with mental retardation require more time than their nondisabled peers to automatically recall information and therefore have more difficulty handling larger amounts of cognitive information at one time. Early researchers suggested that once persons with mental retardation learned a specific item of information sufficiently to commit it to long-term memory—information recalled after a period of days or weeks—they retained that information about as well as persons without retardation (Belmont, 1966; Ellis, 1963).