Throughout history, arguments for black intellectual inferiority have been code for the presumption of black sub-humanity. Such arguments free those with racist white identities to regard every black body with contempt and treat it accordingly. It frees the American past from the stench of its racist crimes by convincing believers that blacks deserved no better than enslavement, apartheid, and state-sanctioned contempt.
There is plenty of convincing work crushing the notion that we can make any scientifically valid determination about what portion of intelligence is hereditary versus environmental, much less break that down by vague racial categories (is someone with 50% Sub-Saharan African DNA "black," what about 40%, or 30?).
What's more interesting is the 'race scientists' reliance on the three ancient pillars of white identity politics. The first pillar is denial of the toxicity of America's racist past. The second is pseudo-science to justify that same toxicity. These work in service of the third, the steadfast belief in a history of white American purity.
In a debate with Vox Editor Ezra Klein on the validity of science-based justifications for the racist insistence on black inferiority, Harris spends the debate negating the relevance of America's history of state-sanctioned and popularly supported racism--on both blacks and whites. During the conversation, Klein accuses Harris of having a "conversation [about race] without dealing with and separating it out and thinking through the context and weight of American history on it."
In reply, Harris baldly states, "The weight of American history is completely irrelevant"" To Harris, a history of enslavement, segregation and state-sanctioned discrimination has not touched African Americans, and a history of institutional insistence on black inferiority has not touched whites.
Similarly, Murray claimed that by the 1970s, a mere 10 years after the passage of the Civil Rights Act, all of the negatives of America's 188 years of state-sanctioned violence and discrimination against African Americans had been corrected for. That means that blacks in America endured 188 years of terrorism, substandard housing, education and healthcare, lack of financial opportunity, and generations of personal humiliation, but all vestiges of that 188 years had disappeared within the next ten.
Later, Klein asks if Harris agrees with the following statement:
[blockquote] I say that the belief that African-Americans are genetically less intelligent than whites, and then also inferior in other ways" is our oldest, most ancient justification for racial inequality and bigotry. Do you disagree with that? [/blockquote]