In the middle of 2014, the chattering classes were gripped by Ta-Nehisi Coates’ outstanding essay "The Case for Reparations," which outlined the history of oppression faced by African-Americans and argued for finally coming to some collective recognition of the evils done to slaves and their descendants. At the end of 2014, many of the same people are debating a 20-year old book of social science, which argues, among other things, that African-Americans as a whole have IQs that fall one standard deviation lower than European-Americans.How did we get here?