As I've argued in this space before, perceived racial differences in academic outcomes (the racial achievement gap) are the product of socioeconomic and environmental inequalities, while differences between individuals (even non-monozygotic twin siblings) are partially genetic.
This position has proven consistently controversial, but I've never quite understood why; it's explicitly rejecting racist pseudoscience while accepting the findings of a vast body of well-replicated research demonstrating that genes influence (not determine!) psychological traits like academic ability. What's more, I find it frustrating how many people reject it given that this belief is perfectly in keeping with the idea that race is a social construct, which is an idea that I believe. Again, the relationship between parents and their children is genetically simple, whereas the relationship between genetically and historically distant people who we have socially categorized into racial categories is extremely complex, inconsistent, and tangled. To think that saying individual genetic differences implies racial genetic differences is to think like a race realist - so it's strange that so many people who accept the social construction of race make that leap!
Here's a passage from a recent (gated, alas) Danish study that I will be writing at length about next week. I think it fits into all of this nicely.
However, recent evidence from the United States indicates that hereditary factors are not a major constraint for low SES students (Nisbett et al., 2012). For example, Tucker-Drob, Rhemtulla, Harden, Turkheimer, and Fask (2011) found no significant differences between children in high and low SES families on the Bayley Short Form–Research Edition (see, e.g., Andreassen & Fletcher, 2007)—a test of infant mental ability—at the age of 10 months, but by age 2 children in high SES families scored about one third of a standard deviation higher than children in low SES families. Genes accounted for nearly 50% of the variation in mental ability of high SES children but only a negligible share of low SES children’s variation, indicating that the latter are not reaching their full cognitive potential. Rhemtulla and Tucker-Drob (2012) found similar patterns of gene and SES interactions in follow-up tests of mathematics skill at age 4 (but no significant interactions in reading). Fryer and Levitt (2013) found no significant differences on the Bayley Short Form–Research Edition among Hispanic, Asian, Black, and White infants aged 8 to 12 months, although a one standard deviation gap in test scores between Black and White children, which typically differ in SES, has been observed by age 3.
Now, how can the "race realists" account for the lack of a racial gap between cognitive abilities in children at 8 to 12 months, and the presence of a large gap at 3? Am I to believe that their genome changed that much in 24-28 months? Or is there a much more plausible explanation - that we have socially constructed racial categories and embedded deep and persistent inequality into our society based on those categories, which in turn results in educational inequality? The race science crowd will insist that we've controlled for socioeconomic status, but this presumes that metrics like income band can account entirely for the relationship between race and socioeconomic reality, which I don't think is true. The impact of race on someone's position in our society is profoundly multivariate, with all manner of pernicious inequalities that are not fully explained by raw metrics of income and wealth.
Meanwhile, the genetic relationship between parents and children, between brothers and sisters, and the lack of same between adopted children and parents/siblings implies a not-particularly-controversial degree of influence on all kinds of outcomes, including academic ability. That, too, is perfectly in keeping with social construct theory - and, as I will keep insisting, functions as a powerful argument for economic redistribution and away from market capitalism.
None of this means that my take on these issues is correct, necessarily, though I think the evidence grows all the time. But the insistence that belief in genetic influence on individual academic talent somehow implies racist pseudoscience seems to me to make the exact same error that racists do: imagining that race must be biologically real.
Update: To briefly answer the "why do you care about differences in individual academic potential" question:
because the belief that everyone has identical academic potential leads inevitably to profoundly conservative "just deserts"-style economics and
the most disastrous education policy efforts in our history, especially No Child Left Behind, have been based on the assumption that there are no constraints on what policy, educators, and schools can achieve, and I'd like us to have good education policy instead of bad.