Autism is a severely incapacitating life-long developmental disability which typically appears during the first three years of life. It occurs in approximately five out of every 10,000 births and is four times more common in boys than girls. It has been found throughout the world in families of all racial, ethnic, and social backgrounds. No known factors in the psychological environment of a child have been shown to cause autism. The symptoms are caused by physical disorders of the brain. They must be documented by history or present on examination. They include: (1) Disturbances in the rate of appearance of physical, social, and language skills. (2) Abnormal responses to sensations. Any one or a combination of sight, hearing, touch, pain, balance, smell, taste, and the way a child holds his or her body are affected. (3) Speech and language are absent or delayed, while specific thinking capabilities may be present. Immature rhythms of speech, limited understanding of ideas and the use of words without attaching the usual meaning to them is common. (4) Abnormal ways of relating to people, objects, and events. Typically, they do not respond appropriately to adults and other children. Objects and toys are not used as normally intended. Autism occurs by itself or in association with other disorders which affect the function of the brain such as viral infections, metabolic disturbances, and epilepsy. On IQ testing, approximately 60 percent have scores below 50, 20 percent between 50 and 70, and only 20 percent greater than 70. Most show wide variations of performance on different tests and at different times. Autistic people live a normal life span. Since symptoms change, and some may disappear with age, periodic re-evaluations are necessary to respond to changing needs. The severe form of the syndrome may include the most extreme forms of self-injurious, repetitive, highly unusual, and aggressive behaviors. Such behaviors may be persistent and highly resistant to change, often requiring unique management, treatment, or teaching strategies. Special educational programs using behavorial methods and designed for specific individuals have proven most helpful. Supportive counseling may be helpful for families with autistic members, as it is for families who have members with other severe life-long disabilities. Medication to decrease specific symptoms may help certain autistic people live more satisfactory lives.