First heard somewhere (don't remember where or exact idea) that neurons initially form groups and these groups then perform functions. This led to an idea that if someone's brain sacrificed some "copy other primate" groups for "pattern recognition" groups, you would get a unit with higher IQ for non social use, without changing the brain to be more effective in general. This would come at a cost to social/copying skills. This idea doesn't explain "systems thinking" tendency or "not seeing forest for the trees" tendency in autist spectrum folks.
On another occasion, it occurred to me that regular brain run / loop consists of a short reality check and longer flow state. If there are too many reality checks, you get anxiety and can't work effectively. OTOH, too little realty checks and you get stuck on non important things. At the same time, impairing this "check to flow" balance in a safe (non anxiety provoking) environment would result in an individual that could perform the kind of deeper work with results not achievable by not modified individuals.
Have watched 50+ h of psychology lectures, but don't have any formal knowledge on these things so please take it with a grain of salt.
Edit: myself I'm formally on ADHD, and in personal opinion also on Autism spectrum. Just learned to "act normal" very well by the time I got into diagnosis.