mental retardationmental retardation
a condition, usually present from birth, characterized by intellectual functioning that is below average: until recently, the preferred technical term, with levels defined in terms of IQ and ranging from borderline (IQ of 71-84) to mild (IQ of 50-55 to approximately 70) to moderate (IQ of 35-40 to 50-55) to severe (IQ of 20-25 to 35-40) to profound (IQ of below 20-25): in technical use, now largely replaced by intellectual disability
Impaired intellectual development resulting from any of various causes, including genetic disorders and brain injury.
- A intellectual disability and developmental disability in which the person has an intelligence quotient below 70 plus difficulty in multiple areas of daily life. Evidence of this disability must have appeared before the person reached adulthood.