Sometimes. A primary characteristic of Autism is a large discrepancy between verbal and visual IQ. Low functioning autism and mental retardation pretty much go hand in hand, with Autism being something in addition to the mental retardation. In some cases low functioning autism presents with extremely superior visual memory and verbal retardation (these are the Autistic savants who can paint photorealistic images from memory, but can hardly talk). In many cases of high functioning Autism there are specific mental deficits or even retardation coupled with specific forms of superior intelligence. For example I have been diagnosed as on the Autistic spectrum, and although I obtain very superior scores on specific tests of verbal intelligence, my scores on specific tests of visual intelligence are quite bad. Most people obtain average scores on all tests of verbal and visual intelligence. In addition to this characteristic intelligence profile, I meet several of the diagnostic criteria for high functioning autism, and have been diagnosed as having a mild form of Aspergers syndrome (which itself is a mild form of Autism).