What IQ Tests Measure

May 17 2013 @ 2:52pm

Brink Lindsey makes some important points about IQ scores. They are designed to predict outcomes in a post-industrial advanced society:

IQ scores clearly tell us something of genuine importance. They are a reasonably good predictor not only of performance in the classroom but of income, health, and other important life outcomes.

Then this qualifier:

IQ tests are good measures of innate intelligence–if all other factors are held steady. But if IQ tests are being used to compare individuals of wildly different backgrounds, then the variable of innate intelligence is not being tested in isolation. Instead, the scores will reflect some impossible-to-sort-out combination of ability and differences in opportunities and motivations.

I’m pretty sure that’s true. The trouble is: IQ researchers are not dumb. And they have done their best to control for background, culture, education, wealth, etc. And when they do, the differences between population subgroups of different ancestries do not go away completely. Brink is dead-right that upbringing is a big deal and can greatly affect the result. But those results tend to start at 8 years’ old and are hard to budge thereafter.

Leaving immigrants aside, in the US, we have not seen among longtime residents what we would expect: a convergence of IQ among all population subgroups. We do have rising IQ rates in general – as our brains adjust to the new and more complex set of tasks our modern society has created for them. There’s no reason to believe that immigrants of one population subgroup won’t rise in IQs over generations – and they have. But the other subgroup populations have rising IQs as well – and the differences do not go away.

Why else do they have a de facto Asian quota at Harvard? Why else did they once have an explicit Jewish one? That’s one of the ironies of affirmative action. The very liberals who deride “race” as a category, use it reflexively all the time in the case of affirmative action. And the upshot of their use is direct discrimination against population subgroups because of their higher scores. Accusations of racism cuts both ways. If the Supreme Court strikes down affirmative action this year, as seems likely, how will resilient differences in IQ between subgroups of differing ancestries be hidden?

Another important bit of Lindsey’s argument, with which I fully agree, is that the kind of intelligence measured by IQ is a very specialized and post-industrial-specific one. It has, as I’ve repeatedly, said, no intrinsic value, morally or otherwise. It’s entirely contingent on our particular kind of society and what kind of brain succeeds best in it on its own terms (of socio-economic advantage). There are many other just as valuable (in my view more valuable) forms of intelligence.

IQ tests reward the possession of abstract theoretical knowledge and a facility for formal analytical rigor. But for most people throughout history, intelligence would have taken the form of concrete practical knowledge of the resources and dangers present in the local environment. To grasp how culturally contingent our current conception of intelligence is, just imagine how well you might do on an IQ test devised by Amazonian hunter-gatherers or medieval European peasants.

The mass development of highly abstract thinking skills represents a cultural adaptation to the mind-boggling complexity of modern technological society. But the complexity of contemporary life is not evenly distributed, and neither is the demand for written language fluency or analytical dexterity. Such skills are used more intensively in the most advanced economies than they are in the rest of the world. And within advanced societies, they are put to much greater use by the managers and professionals of the socioeconomic elite than by everybody else. As a result, American kids generally will have better opportunities to develop these skills than kids in, say, Mexico or Guatemala. And in America, the children of college-educated parents will have much better opportunities than working-class kids.

And yet the median score for very wealthy subgroups is often lower than the median score for poorer subgroups. That’s the truly surprising result of the research, as you will find if you ever actually bother to read The Bell Curve, rather than simply dismissing it. Reihan calls Lindsay “entirely correct”:

Yet its implications for the immigration debate are not entirely clear. As a matter of distributive justice, discriminating against a given class of persons on grounds of inherited disadvantage seems profoundly unfair. And if we collectively decide that our immigration policy ought to be crafted with global distributive justice foremost in mind, admitting large numbers of less-skilled immigrants is obviously the right thing to do, given the size of the “place premium.” But if our goal is instead to recruit immigrants who are likely to flourish in an advanced economy, the case for assessing immigrants on the basis of whether or not they possess the highly abstract thinking skills associated with success seems much stronger. This would be the case whether or not a relative lack of the skills in question reflects some intrinsic quality (which, like Brink, I’m pretty sure is not the case) or contingent historical circumstances.

That’s why I favor giving foreign grad students an automatic green card with their diploma. But there should be no IQ-based testing of immigrants. We’d be a much less rich and genuinely diverse country if we did that.