According to the American Association on Mental Deficiency (AAMD), what are the three basic features of intellectual disability?

a) Sub-average intellectual functioning, deficits in adaptive behavior, and genetic factors

b) Sub-average intellectual functioning, deficits in adaptive behavior, and late onset during adulthood

c) Sub-average intellectual functioning, deficits in academic skills, and early onset during childhood

d) Sub-average intellectual functioning, deficits in adaptive behavior, and developmental period manifestation

d

The American Association on Mental Deficiency (AAMD) views intellectual disability as “significantly sub-average general intellectual functioning existing concurrently with deficits in adaptive behaviour and manifested during the developmental period”. This definition points to three basic features. First, in order to be judged as intellectually disabled, a person must show significantly sub-average intellectual functioning. Persons having IQs below 70 are judged to have sub-average intelligence. The second relates to deficits in adaptive behaviour. Adaptive behaviour refers to a person’s capacity to be independent and deal effectively with one’s environment. The third feature is that the deficits must be observed during the developmental period, that is between 0 and 18 years of age.