One part family life, one part the instilled ambition to be better.
Ben Carson, a “black” man and former brain surgeon, grew up in poverty with a single-mom. But she was a Godly woman who raised her sons right, and gave to them, instilled in them, the ambition to be better. His genetics did not hurt him.
The third part of the answer is it’s not genetics.
Immigrants of all sorts come with the ambition that they have to push themselves and their kids to get ahead here. On average most legal immigrants do not sit back and rely on average ambition to do well. They figure that will not be enough.
About 88% of Asians in the U.S. are 1st and 2nd generation immigrants.
I have often thought that Jewish people tend to be so successful simply because their culture values and EXPECTS professionalism and success.