This combination of intellectual variations makes autism especially perplexing. Marked restriction of activity and interests. A person who has autism may perform repetitive body movements, such as hand flicking, twisting, spinning, or rocking. This individual may also display repetition by following the same route, the same order of dressing, or the same schedule everyday, etc. If changes occur in these routines, the preoccupied child or adult usually becomes very distressed.
Autism is a brain disorder, present from birth, which affects the way the brain uses information.
The cause of autism is still unknown. Some research suggests a physical problem affecting those parts of the brain that process language and information coming in from the senses. There may be some imbalance of certain chemicals in the brain. Genetic factors may sometimes be involved. No factors in the psychological environment of the child cause autism.