Kind of difficult, if you do bad on an IQ test then yeah...
However that is sometimes more a matter of communication- if you get given this piece of paper with these weird and irrelevant questions on it when you would rather going back to solving quantum string theory in your head so you do badly, well you would be considered ret*d.
I would guess quite a few autistic people would be along those lines, they don't really understand the point of the test or why they should do it. Coupled with trouble communicating what is going on in their head, even if it is possibly brilliant or world altering.