What is mental retardaton?

Mental Retardardation is the lack of normal development of intellectual capacities. This condition causes the person to have an IQ of 70 and below, which affects the person's learning, behavior and development. This condition is present at birth. Mental retardation can be caused by genetic influences example; down syndrome or autisim. It can also be caused by environmental influences example; fetal alcohol syndrome, childhood diseases, malnutrition, exposure to environment, inadequate medical care. Mental retardation is classified into four types:
Mild- people who are categorize between 50 and 70 IQ. They are able to live independently.
Moderate- people who are classified in the 40's IQ. They need assistance living care.
Severe- people who are classified in the 30's IQ. These are more organic reasons.
Profound- people who are classified in the 20's and below IQ. They are more biological.