The narrower we define autism, and the more strictly we control for particular behaviors, the more likely we are to find what I think are the subgroups of autism.

I think that if I could do any sort of research of autism that I wanted to do, at this point I would take a sample of classic, early infantile autism persons and compare them with what I call "classic late onset autism", individuals. I think we will find that the cause of those youngsters with autism who have autism from birth is probably different than those who have late onset autism.

There does seem to be a higher educational level in parents of autistic youngsters, and I guess that's something that we need to look into.

The ways in which acquired savants show up are usually the same ways that congenital, or non-acquired, savant syndrome shows up. They tend to show up in the same areas: music, art, math, visual, spatial skills, and calendar calculating, although calendar calculating probably isn't quite as prominent in that group. They tend to show up quite quickly, or sort of explode on the scene and they then tend to have an obsessive sort of forceful quality about them in the same way as savant skills. So they tend to show up in the same ways.

When I met my first savant in 1962, I was impressed by the abilities in these youngsters who had severe disabilities. They appeared to me to be islands of genius in the sea of disability. So I've maintained that word picture since that time, of these islands of genius that are so striking and so jarring when you see them, especially in people who have severe disability.

There is such a thing as genius, and these are people who do not have a formal disability, DSM-IV-type. They may have liberal eccentricities or quirks in their personality, but they don't rise to the level of a disability.

We have to be careful that we don't keep multiplying disorders and diluting them. I think there is a difference. People talk about Asperger's as high-functioning autism, which I think it is. But it does have some of its own characteristics, like the preservation of language, particularly, which may be right brain dysfunction instead of left brain dysfunction, and we lose something in that, as things lose their specificity, and we keep diluting things. I'm not sure that's helpful.