The stereotypical view of autism is that portrayed by Dustin Hoffman in the movie Rainman -- an individual unable to function well in society, with unusual mental abilities, repetitive behaviors and odd speech patterns. Autism today is recognized as a developmental disorder that begins either at birth or in very early childhood, and if left untreated, can seriously impair a child's ability to develop normal social interactions.

Autism appears in anywhere from one in 166 births to one in 500 births; it was earlier thought to occur only once in every 10,000 births. It is not clear whether recent increases in diagnoses of autism are due to better diagnostic criteria or to an actual increase in incidence of autism. The causes of autism are the subject of considerable controversy, although a genetic propensity, possibly triggered by environment factors, is a leading candidate. Certainly autism or autistic characteristics can be seen to run in families.

Autism is believed to be a neurological and sensory disorder; autistics do not perceive and relate to the rest of the world in the same way as non-autistics. Temple Grandin, an autistic who gained a PhD in animal behavior as an adult, has written of her life with autism in Thinking in Pictures. She claims an autistic's cognition is much more closely tied to visual stimuli than that of non-autistics.

Autism in children can be diagnosed very early, as early as 12-18 months. The signs of autism include:

• Language development problems: An infant may babble and begin to acquire one-word concepts, then at some point cease to learn new words and lose the ones they have already required. Some autistic children never begin to develop language at all.
• Social retreat: Rather than enjoy and seek out social interactions, a toddler with autism will avoid them, preferring their own company. A child who actively, even obsessively, avoids eye contact may be in the early stages of autism.
• Sensory problems: Autism seems to interfere with how a child processes sensory information. Tactile sensations may be overwhelming or addictive. Visual stimuli such as the rotating blades of a fan may prove an irresistible focus for an autistic.
• Repetitive behavior: Autism often makes itself visible in children who perform ritualistic or repetitive motions. Hand flapping, organizing toys rather than playing with them, and opening and closing cabinets repeatedly for a lengthy period may all be hallmarks of autism.

Autism is considered a spectrum disorder -- that is, problems caused by autism can range from mild to severe. The earlier autism is diagnosed and treated, often by cognitive and behavioral intervention, the more fully functional autistics can become. Many autistics diagnosed today can be successfully 'mainstreamed' into the educational system. Many municipalities now have special services in the educational system to treat autistic children; consult with your pediatrician for information on diagnosis and treatment if you think your child might be autistic.