" Racism” as a blanket explanation of intergroup differences is not simply an over-rated explanation. It is itself a positive hindrance to a focus on the acquisition of the human capital or cultural capital needed to rise economically and socially. If there is any central theme that emerges from the histories examined in these three volumes, it is that the cultural capital of a people is crucial to their economic and social advancement, whether that people is a racial minority, a nationstate, or a whole civilization. In some cases, the factors inhibiting the development of this human capital have been geographical or historical. But they need not include self-inflicted ideologies or ideologies congenial to sympathetic outsiders, whose sympathies may prove to be more of a handicap than the hostility of others. "

― Thomas Sowell , Conquests and Cultures: An International History