[bjourne]

Most believe that there is a common source for varying diagnoses like ADD, ADHD and high functioning Autism. What that source is, is not yet known but people have hypothesized about certain genes causing it, or changes in the prenatal environment.

The disorder is much more prevalent in some families than others and even in some ethnic groups which strongly suggests that there are genes involved. One theory suggests that the genetic material came from when Homo Sapiens interbred with Neanderthals.

Autism is in some ways very similar to homosexuality. There is no one true test for it, but if you "look for the signs" you can "diagnose" even very young children. It implies that autism, like homosexuality, can't be cured. People with the disorder have to live with it and those around them have to adapt because they can't change themselves.