You're approaching this from a scientific perspective. The other approach is political/sociological. Neither of you are wrong. I get that it can be demoralizin

You're approaching this from a scientific perspective. The other approach is political/sociological. Neither of you are wrong. I get that it can be demoralizing, but I'd suggest it serves your cause better to be able to point to high-functioning cases as success stories to mitigate the stigma, lest the rest of the spectrum be dismissed as retarded beyond redemption (hence, eugenics).