I think this impressive achievement is more a testament to the role that aspirations acquired during childhood play in determining a person's success than it is a reflection of this young man's intelligence. Yes, the latter is necessary, but it isn't sufficient. I have little doubt that there are many 18 year olds entering MIT's class of 2019 who could have entered at 15 had they been provided a similarly advantageous upbringing.
These stories attract the attention of some of us because we wish we had been raised similarly. Had we not devoted our attention as children to, say, petty family turmoil or a hedonistic preoccupation with computer games, perhaps we would have progressed through life with a singularity of purpose and self-confidence that would have situated us in a better position today. We might have been spared years in our teens and twenties trying to find a sense of meaning in our work, unlike this fellow, who seems to have it figured out.
I won't speculate about his social skills. I've met college students his age running the gamut from borderline autistic to social butterfly. Yes, the sense of "peerlessness" must be a bit alienating, but many of us have had this experience without leapfrogging high school.