Autism causes a lag in language ability for mental age, social isolation from poor relatedness, and stereotypic movements (purposeless repetitive movements that go away when busy, such as hand flapping, or finger flicking). One should think of it as a very broad final common pathway for likely hundreds of undiagnosed conditions. It is similar to the word, fever, or the phrase, mental retardation. It does not exist as a unified disease. Asperger Syndrome differs from autism in that that language is fluent, and the patient talks too much, lecturing on a narrow subject, even to people who are not interested.
These features overlap with the negative symptoms of schizophrenia, another likely very broad syndrome. They are reliable predictors of a poor, outcome, unified by the lack of social interest or relatedness. One should think of all these patients as mentally retarded. Even if the autistic person has an IQ of 110, he will always come from families with IQ's of 140, and is thus mentally retarded for that family. All of the high IQ patients operated markedly below their expected level of tested function.That was the traditional way to make the diagnosis.
How did the rate go from 1 in 2000 to 1 in 100?
1) Services attracted parents to school districts. Open a program, and the autism rate will shoot up. Do not investigate the water, just the school system for a cause of increased rates.
2) Doctors are making the diagnosis in merely immature children, often with ADHD. It is not well known that 20% of boys will not have spoken by age 3. So they get enrolled in expensive special education programs, with rich parents hiring aggressive lawyers to intimidate school systems for more services at taxpayer expense. Come age 5, these kids become chatter boxes, and the aggressive bullying now appears to hav been justified. It is just spontaneous onset of speech. The most famous of these children was, of course, Albert Einstein. He did OK for himself.
3) The assault on the American family by the feminist lawyer is nearly victorious. Bastardy is associated with out of control child behavior. The immaturity and poor socialization is misdiagnosed as a serious condition because of the massive benefits of this diagnosis, compared to the criticism of the mother's promiscuity and the bastardy of her offspring. Such criticism is taboo, and would result in the firing of any child welfare worker. The reason is that bastardy and its huge increase in social pathologies generates massive government make work jobs. Any criticism of the mother would threaten government jobs, and there is zero tolerance for it. Thus the absence of this most likely of all causes in the article.