Autism, disorder that severely impairs development of a person’s ability to communicate, interact with other people, and maintain normal contact with the outside world. The disorder was first described in 1943 by American psychiatrist Leo Kanner. One of the most common developmental disabilities, autism affects 2 to 5 out of every 10,000 children and appears before the age of three. It is four to five times more common in males than in females. IICHARACTERISTICS
Autism is often referred to as a spectrum disorder—that is, a disorder in which symptoms can occur in any combination and with varying degrees of severity. Symptoms of autism usually begin during infancy. Autistic infants may stiffen or go limp when picked up by parents rather than clinging or cuddling up to them. Autistic infants often show little or no interest in other people and lack typical social behaviors. For example, they may not smile at their mother’s voice or make eye contact with caregivers. Autistic children fail to develop normal relationships with their parents, brothers or sisters, and other children. Often they seem unaware of the needs and feelings of other people, and may not respond if another person is hurt or in distress. They also fail to make friends. Children with autism usually play alone. Often they engage in repetitious activities, such as arranging objects in meaningless patterns, flipping a light switch on and off, or staring at rotating objects. Some engage in repetitious body movements, such as spinning, flapping their arms, swaying, rocking, snapping their fingers, and clapping or flapping their hands. In some cases these movements may be harmful, involving repeated biting of their wrists or banging their head. Children with autism frequently become upset at minor changes in their surroundings and daily routines. Autistic children also have difficulties with language. Some never learn to speak or develop very limited speech. An autistic child may say “you” when he means “I” and produce incorrectly formed sentences. For example, when the child wants a drink he may say, “You want a drink.” Autistic children may also demonstrate echolalia, mechanically repeating words or phrases that other people say. About 75 percent of autistic children are classified as having mental retardation, meaning that they score well below average on a standard test of intelligence and that they have a significantly impaired ability to cope with common life demands. Many show great variability in their skill levels across different aspects of intelligence tests, characteristically scoring higher on tests of visual-spatial skills and rote memory than on tests of verbal skills and social understanding. Some experts argue that standard intelligence tests are inappropriate measures of an autistic person's intellectual abilities. These experts note that some symptoms of autism—such as speech and language problems, difficulty paying attention, and behavioral problems—may interfere with an autistic child's performance on standard intelligence tests. Children and adults with autism who score in the average or high range on intelligence tests are considered to have high-functioning autism. About 10 percent of autistic individuals have extraordinary talents such as the ability to memorize long lists of information, the ability to make lightning-fast mathematical calculations, or precocious musical or artistic abilities. Experts call such individuals autistic savants. Savants may score above or below average on standard intelligence tests. IIICAUSES
Scientists once regarded autism as a psychological disorder caused by traumatic experiences that forced a child to retreat into a world of fantasy. Some theorized that parents caused autism by unconsciously rejecting a child, or by failing to bond emotionally. These theories caused enormous guilt in parents and lacked any scientific validity. Scientists today still do not know what causes...