Can't do it full justice right now but I see a couple factors.
1. You've gotta be pretty well-educated and self-motivated to be allowed to immigrate from an African country. Comparing the average "ADOS" to the average African immigrants isn't apples to apples.
2. There's a lot of value in NOT being brought up with American conditioning on race. Africans are well aware of racism but I think they generally approach the American form of it differently than ADOS. I think that's largely from growing up with a plethora of black role models in business, educations, etc and not experiencing race as a limiting factor (tribe, religion, class, and gender are way more important).
America conditions many black people to not even try to reach their potential. So I think being raised outside of that conditioning (or even being raised by someone who was raised outside of that like I was ) reaps a lot of rewards.