INTELLECTUAL DISABILITY An individual with mental retardation (MR) is best characterized as having both low to below-average thinking and reasoning skills as measured by a standardized intelligence test, and a limited ability to function in areas of daily life including communications, self-care, and social and interpersonal skills. A diagnosis of MR also requires that the condition occur in the developmental years, prior to age 18. RISK FACTORS This affects about 1%-3% of the population. Only 25% of the cases have a direct reason why intellectual disability is acquired. Here are some examples of the risk factors: Infections (before, during and » » » [Read more]