[chownie]

> A reasonable guess, but if that was the case we would expect low functioning autism to be extremely uncommon compared to either "mild" autism or other developmental issues, since very few kids would happen to fall under both conditions.

Diagnosis of autism requires running through a checklist as part of an interview, or a behavioural analysis if younger. If you're completely non-verbal and thus incapable of being interviewed you can still be shortcut diagnosed as autistic, which is actually my entire point, the behavioural checklist is not that stringent. A number of severe learning disabilities can pretty easily be swung into an autism diagnosis, making the spectrum seem more like 20 conditions we can't distinguish rather than 1 condition with vastly differing presentations.