This document discusses mental retardation/intellectual disability including its nature, characteristics, causes, manifestations, history, and ethical issues. It defines mental retardation as subaverage intellectual functioning and impaired adaptive skills that manifests during development. Causes include prenatal factors like maternal alcohol/drug use and infections. Manifestations involve delayed skills and difficulty adapting. The history discusses early conceptualizations and the development of treatment programs in the 18th-19th centuries. Ethical issues concern patient autonomy and the cultural construction of mental retardation.