Yes, you're right. Austistic people are definitely NOT stupid. My brother is in the same age range as yours, and they sound very much alike.
My bother is 46, doesn't speak at all, but certainly can communicate, in very creative ways. His IQ is very high. I don't know what he tested at, but he is quite smart. I read somewhere that high IQs tend to run in not only autistic people but in their siblings. I also was taught that autism occurs mainly in first-born males, but apparently that's no longer correct, so I don't know.
Terry taught himself to read, because of his fascination with the TV. He was spelling with his blocks when he was 3 years old. He uses his TV Guides to look up the spellings of words.
Anyway, if you ever want to discuss our brothers, just freepmail me. I rarely have the opportunity to talk to other people with autistic loved ones in that age range because it was so rare back then. It would be interesting to compare notes.