Definition of Mental Retardation

Mental retardation is not something you have, like blue eyes, or a bad heart. Nor is it something you are, like short, or thin.

It is not a medical disorder, nor a mental disorder.

Mental retardation is a particular state of functioning that begins in childhood and is characterized by limitation in both intelligence and adaptive skills.

Mental retardation reflects the ˝fit˝ between the capabilities of individuals and the structure and expectations of their environment.

The AAMR Definition of Mental Retardation

Mental retardation is a disability characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social, and practical adaptive skills.

The disability originates before age 18.

Five Assumptions Essential to the Application of the Definition

Limitations in present functioning must be considered within the context of community environments typical of the individual’s age peers and culture                                             

1. Valid assessment considers cultural and linguistic diversity as well as differences in communication, sensory, motor, and behavioral factors.                                                    
2. Within an individual, limitations often coexist with strengths.                                          
3. An important purpose of describing limitations is to develop a profile of needed supports.                                                                                                                          
4. With appropriate personalized supports over a sustained period, the life functioning of the person with mental retardation generally will improve.                         

Founded in 1876, AAMR is an international multidisciplinary association of professionals. The Association has had responsibilities for defining mental retardation since 1921.