That may be - especially for Asbergers, with its milder effects- but there is a huge difference between the affect of Down Syndrome or Cerebral Palsy and autism. In my day- and I am 75 - I knew no one who was, or who had, a child with the unique problems that come with full blown autism.

It is true that there were no special classes in my schools for 'different' kids so it is quite likely they would not have been in my schools, but it is also true of my church and of my neighborhoods.

The perceived explosion of autism is not solely the result of more extensive knowledge.