Learn about intellectual disability , a neurodevelopmental condition that affects learning, behavior, and adaptive skills. Find out the types, symptoms, diagnosis, causes, and treatment options for this common developmental disability . Intellectual disability (ID), also known as general learning disability (in the United Kingdom), [3] and formerly mental retardation (in the United States), [4][5][6] is a generalized neurodevelopmental disorder characterized by significant impairment in intellectual and adaptive functioning that is first apparent during childhood. Intellectual disability is a condition in which your brain doesn’t develop properly or function normally. Learn about symptoms and causes. Learn about the symptoms, causes, and treatments of intellectual disability , including its impact on intellectual functioning and adaptive behaviour.