You have a broad and charitable definition of normal. The exceptionally low-set ears, the eyebrows that curve to the bottoms of the eyes, the absence of lips, the pinpoint nostrils, and the niblet teeth are all symptomatic of a genetic aberration. Such congenital problems are typically, if not always, comorbid with some form of impaired cognition. In John's case, what you see is what you get.
Also, do we really know when John graduated from high school? I think that all we know is when he was a senior, which is not the same thing. It's more than possible that he failed classes that year and that he had to make up those courses -- probably at a private school or with a tutor -- delaying his admission to Ole Miss. After all, he was classified as a senior at Ole Miss for at least three years before leaving without graduating. The fact that he never talks about this lost year is telling. Maybe he was institutionalized.
