Great article on the Autism Speaks blog about research in non-verbal children. I think this small section of the article hits the nail on the head for me....I can't even begin to say how many times I've felt this way, especially after seeing those standardized tests put Ayden at his normal age range for cognitive skills!
An estimated 30% of individuals living with autism are functionally non-verbal, yet very little research effort was directed toward helping this group communicate their wants and needs. The inability to communicate leads caregivers and clinicians to the presumption that the cognitive skills in these individuals were low because the tests typically used to assess cognitive skill require verbal or behavioral responses that this group of individuals does not readily produce.
Go here to read the article.