“Intellectual Disability” is a disability characterized by significant limitations in both intellectual functioning and in adaptive behavior, which covers many everyday social and practical skills. This disability originates before the age of 18,
and includes a student whose intelligence test score is two or more standard deviations below the norm on a standardized individual intelligence test, existing concurrently with deficits in adaptive behavior and academic achievement and manifested during the developmental period, and that adversely affects a child’s educational performance.