The Dickens-Flynn model of IQ, part 4: Implications.

What are the implications of the Dickens-Flynn model – for analysis of race, education, inequality, and other aspects of human nature?

The most important thing, it seems to me, is that the Dickens-Flynn model makes it easy to explain racial IQ differences without suggesting that blacks are genetically less able. This was never impossible, but under the Jensen model it was difficult to imagine how the circumstances of black families could be so consistently awful as to explain the size of the IQ gap. So the preferred solution to this problem was to shun IQ researchers, call them racists, and deny mountains of research showing that IQ is important. That’s actually still the most common solution, but thanks to Flynn’s model (and probably also thanks to haranguing by Fredrik deBoer and Scott Alexander), a few liberal outlets – especially Vox – are gingerly dipping their toes in the waters of “maybe not being IQ denialists.” Flynn proved that liberalism’s commitment to racial equality is fully compatible with its commitment to empiricism, which is a really big deal.

It also seems to me that the Dickens-Flynn model justifies affirmative action in its current form. The model implies that IQ comparisons within cultures are meaningful, but that IQ comparisons between cultures are complicated. The gap means something – there are certain styles of abstract reasoning that are valued differently across cultures – but white doctors and lawyers did just fine in the 1950s with test scores similar to black college students today, so there’s every reason to think black people are just as qualified to be doctors and lawyers, despite the IQ gap. Since the LSAT/MCAT, and especially the SAT, are mostly tests of IQ, that may mean we should make adjustments to the test scores of black applicants.

But I don’t think the Dickens-Flynn model has all that much to say about IQ differences within race. When I first read Flynn’s basketball analogy, I thought he was saying something radical – that small differences in educational experience could radically alter someone’s IQ and the course of their life. I realize now that’s not the case – in fact, the model says IQ tests do an excellent job measuring relative cognitive ability within cultural groups, because people have a strong tendency to sort into environments based on their cognitive talent (whether this “sorting” is truly voluntary is a difficult question, but at it’s at least not terribly coercive, and it reflects real differences in talent.)

The Dickens-Flynn model is not as pessimistic about education as the Jensen model, but neither is it as romantic as your average Obama-era liberal. Education, it seems, has some ability to make society smarter in the long term, but its impact on IQ and other measurable factors for individuals is small. Which suggests that if we want to make outcomes more equal for poor children, improving their schools isn’t an especially high-leverage solution. Instead, we should focus on the tools of the New Deal – unionization, social insurance, and the like (which isn’t to say that we shouldn’t improve schools; merely that improving schools is not a solution for the specific problem of inequality.)

I will close with some observations on why studying IQ is important. I don’t have a formal meta-analysis or anything, but a variety of sources suggest that someone with an IQ of 115 – one standard deviation above the norm – will earn on average roughly 30% more than someone with an IQ of 100. That’s an effect roughly as large as the wage gap between women and men or between blacks and whites, which tells me that IQ is an important source of stratification in our society. That doesn’t mean that everyone with a high IQ will outearn everyone with a low IQ, any more than every man with outearn woman or every white person will outearn every black person. But it seems foolish to ignore any of these factors on those grounds.

Flynn’s background as a researcher is unusual – he was originally professor of moral philosophy (as I found out in some of the longer, more rambling chapters of What Is Intelligence), and when he learned that Arthur Jensen, one of the most respected researchers studying intelligence, believed that that racial IQ differences were partly genetic, he was so disturbed that he began tracking down data to see whether the gap between blacks and whites was closing over time. While doing so, he accidentally (re-)discovered the Flynn effect, and as a result, he become one of the most respected researchers studying intelligence.

His example is a hard one to follow, but more environmentalists should take at least some inspiration from it. Flynn is brutally honest about the usual quality of arguments on his own side: “I thought that the first replies published to rebut Jensen were pathetic, and still do.” The problem I see, over and over again, is that environmentalists try to make a much stronger case against innatism than can possibly be made – denying that IQ is associated with real-world outcomes, claiming large shared-environment effects, and so on. And Dunning-Kruger is in full effect; they’re so certain that they’re right that they make elementary mistakes:

  • Flatly misunderstanding heritability.
  • Citing journalists, while their opponents cite scientists.
  • Revealing complete unfamiliarity with the ideas of the people they criticize.
  • Asserting things that a quick Google search would show to be false.

It’s embarrassing, frankly.  I suspect this sloppiness comes from people who have been told for decades, by journalists and other non-experts, that the science has been settled in their side’s favor. After all, why bring out the big guns if the war is over? Flynn warns someone who thinks (for slightly different reasons) that these issues deserve no further research: “Rose should be very certain he is correct. If not, and if he converts the rest of us, only Jensen and those of his persuasion will publish; and they will win the minds of students because the rest of us have all adopted a policy of unilateral disarmament.”

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