You would be surprised, but many 'smart' or 'successful' people fall into the spectrums of asperger's or ADHD. You have Newton who would work on mathematical formulas until he was sick. If Mark Zuckerberg isn't autistic, then I am a billionaire.
There are many more. The issue is most diagnosis are made for those that are behavioral issues. Those that internalize, or use their disorder for what is deemed socially acceptable go unclassified. Those cases fall into the "edge of the spectrum."
To me, it is a genetic variation that has made humans successful. At one point it was normal for math nerds to be socially incompetent. I have been to engineering conventions, and let me tell you. A behaviorist would pass out mentally diagnosing individuals. I pick on math because those are the types I deal with. You also have the literary side.