Intellectual Disability

What is an Intellectual Disability?

The United Nations World Health Organization (WHO) uses this definition of intellectual disability. According to this definition, the criteria for intellectual disability include three major elements, all of which must be present. These criteria are:

• Intellectual functioning that is below average. To meet this standard, a person’s IQ score must be within or below the range of 70-75.


• Adaptive behaviour that is significantly impaired in two or more areas (communication, self-care, home living, social/interpersonal skills, use of community resources, self-direction, functional academics, work, leisure, health, and safety). Marked impairment in two or more of these areas alters the degree to which an individual can meet the expected standards of personal independence and social responsibility.


• Intellectual disability must be evident during the developmental period. This is generally considered to be from conception to 18 years of age.

An intellectual disability may also be referred to as a cognitive or developmental delay/ disorder.

However, individuals with disabilities are people first, with the same needs and desire as other people. Disability is a natural and normal part of the human experience that in no way diminishes a person’s right to fully participate in all aspects of society.