Definition

Mental retardation is a developmental disability that is marked by lower-than-normal intelligence and limited daily living skills. Mental retardation is normally present at birth or develops early in life.

Description

Mental retardation is defined by two standards. The first standard is a person's level of intelligence. Intelligence levels are usually measured by special tests called intelligence tests. Intelligence tests provide a numerical ranking of a person's mental abilities. That ranking is called an intelligence quotient or, more commonly, an IQ. In general, a person with an IQ score of less than 75 is said to be retarded.

The second standard for mental retardation is adaptive skills. The term "adaptive skills" means how well a person can deal with the tasks of everyday life. These tasks include the ability to speak and understand; home-living skills; use of community resources; leisure, self-care, and social skills; self-direction; basic academic...