[stcredzero]

The above is discussed in Thomas Sowell's Migrations and Cultures.

An overarching theme in Thomas Sowell's books: The world is ruled by human capital, that is: cultures and people's ideas of how the world is and should be. Thinkers like Jordan Peterson would add that the world is also ruled by various forces working below the level of consciousness, for which humans have developed religion and art to try and deal with -- which also fall under the rubric of culture.

I think it's Culture which is the dominant factor, and this is a great foundation of hope. It means that all of the greatest accomplishments of human civilizations are available to all peoples, given enough effort to transform one's understanding and way of life. Such is the power of culture, that this effort may take generations to accomplish. History bears this out. If the descendants of Irish peasants (who, during the potato famine could start out 1/2 to 1/4th as wealthy as the average US slave) could arrive at their current place in modern society, then there's basically nothing that cultural transmission can't accomplish, given enough resources and time.