It's impaired or incomplete mental development. People who are mentally retarded are limited in their ability to learn and their capacity for putting learning to use. Despite their limitations, they have more similarities with others than they have differences.
Retardation is a major social, educational and health problem in America today.
No, mental retardation and mental illness are separate problems. Both require understanding and treatment as early as possible. Social - lack of mental stimulation, physical abuse, poverty, discrimination and other nonmedical conditions. There is no measurable damage to brain tissue itself in most cases of retardation. Return to Top 8 Leading Known Causes of Mental Retardation 1.