Table 2.

Definition of Intellectual Disability and Assumptions Regarding Its Application (AAIDD, 2020, p. 1).

Intellectual disability is characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social, and practical adaptive skills. The disability originates during the developmental period, which is defined operationally as before the individual attains age 22. The following five assumptions are essential to the application of this definition: Limitations in present functioning must be considered within the context of community environments typical of the individual’s age peers and culture. Valid assessment considers cultural and linguistic diversity as well as differences in communication, sensory, motor, and behavioral factors. Within an individual, limitations often coexist with strengths. An important purpose of describing limitations is to develop a profile of needed supports. With appropriate personalized support over a sustained period, the life functioning of the person with ID generally will improve.