That said, the ability to correctly diagnose does improve over time. I keenly remember a "stupid kid" in school who was simply put in the 7th grade retarded division. As an adult he self-diagnosed dyslexia and went about solving it. He has since done very well.
"a child is behind his contemporaries, it MUST be due to a
desease over which neither he nor his parents have any control. They're all "victims," instantly removing any hint
of responsibility. "
Especially if they happen to be boys who need to be held back because they just happen to be too smart for their own good.
Einstein would have been labelled autistic if he were a young boy today.