Conditioning? Not sure what you mean. But the fact that immigrant blacks do so well is more an attribute to their behavior in society than the way society views them. You could take a black man from Sudan, and one from Detroit and put them together. Why is it that anyone hiring for a job would take the Sudanese man 9 times out of 10 for a position over the man in Detroit - assuming both have equal qualifications? It's obviously not skin color.
I am suspicious that African immigrants in the US have 2 advantages :
1) the one who emigrate are usually extremely well educated and very well schooled.
I did meet one of the group of Sudanese eye surgeons : well their achievements was simply extremely impressive. Not even in Europe people would have trained so well and practiced and retrained in so many
foreign countries
2) they have the advantage of surprise : if a recruiter is expecting a "savage" , and sees a polished well behaved African, may be that plays to their advantage.
What I'd like to find out is how children from African immigrants fare within the US
system, as these would have been exposed to the youngest age to how the US views
and depicts their skin color : do they fare as badly as the one bred and raised in the US
or do they fare as well or better than their parents ? And the other questions being
did their parents need to shelter them from US conditioning?
I remember reading that some parents took on themselves to send their kids
back home when starting school, for them to return just few years before University.