IDEA defines intellectual disability as significantly sub-average general intellectual functioning existing concurrently with deficits in adaptive behavior and manifested during developmental periods that adversely affect a child’s educational performance.
Many children with mild intellectual disabilities are not identified until they enter school. They may master academic skills up to about the grade level and learn job skills to be able to support themselves independently. Children with moderate disabilities show significant delays in intellectual and adaptive functioning as they grow. Discrepancies grow wider between these children and typical peers in the classroom. They will also have more health and behavior problems than individuals with mild disabilities. Individuals with severe and profound intellectual disabilities are identified at birth or shortly afterward. These infants have significant central nervous system damage and have additional disabilities or health conditions.
The key characteristics of students with intellectual disability significantly show that they are below grade level in reading and learning basic math skills. Their cognitive skill deficits are memory, slow learning rates, attention, and generalization. Students have difficulty remembering information especially short-term memory. They have a hard time remembering a specific sequence of job tasks or following instructions. Individuals with intellectual disabilities often have difficulty sustaining attention to learning tasks and lack interest in learning or problem-solving tasks. Individuals with intellectual disabilities have substantial deficits in adaptive behavior. They show limitations in self-care skills such as dressing, eating, and hygiene. Making and sustaining friendships and personal relationships can be challenging due to inappropriate behaviors and poor language development. Language and communication skills fall behind the average. School learning also can be challenging because they acquire new knowledge and skills slower than their typical developing peers. They may need 20 to 30 more trials to learn a geometry concept while the typical developing peers may take only 2 or 3 trials.
Instructional strategies used to increase memory abilities for students with intellectual disabilities are focusing on teaching metacognitive skills or control strategies such as rehearsing and organizing information into related sets. To teach adaptive behavior, direct instruction and environmental supports such as added prompts and simplified routines are needed.