Purpose of review:
Current diagnostic criteria for intellectual disability categorize ability as measured by IQ tests. However,
this does not suit the new conceptualization of intellectual disability, which refers to a range of
neuropsychiatric syndromes that have in common early onset, cognitive impairments, and consequent
deficits in learning and adaptive functioning. A literature review was undertaken on the concept of
intelligence and whether it encompasses a range of specific cognitive functions to solve problems, which
might be better reported as a profile, instead of an IQ, with implications for diagnosis and classification of
intellectual disability.
Recent findings:
Data support a model of intelligence consisting of distinct but related processes. Persons with intellectual
disability with the same IQ level have different cognitive profiles, based on varying factors involved in
aetiopathogenesis. Limitations of functioning and many biopsychological factors associated with intellectual
disability are more highly correlated with impairments of specific cognitive functions than with overall IQ.
Summary:
The current model of intelligence, based on IQ, is of limited utility for intellectual disability, given the wide
range and variability of cognitive functions and adaptive capacities. Assessing level of individual
impairment in executive and specific cognitive functions may be a more useful alternative. This has
considerable implications for the revision of the International Classification of Diseases and for the cultural
attitude towards intellectual disability in general
