Thursday, December 13, 2007

The Flynn effect and the conceit of IQ tests.

James Flynn
What Is Intelligence?
Cambridge; $22

I cringe whenever someone invokes his or her IQ score in the course of bullshit justification—as if the ability to "pick the shape that doesn't belong" were the only indicator of intelligence. Citing your MENSA membership doesn't make you smart; rather, it exposes the unfortunate extent of your douchebaggery.

Now, I get that pattern recognition undoubtedly plays a large role in that amorphous quality we call "intelligence," but I think we can agree that some people will respond better to geometric shapes than others. It all stems from Plato's contention that there is something mystically universal about geometry that every *intelligent* human being surely understands. The logic problems on IQ tests are concerned with Aristotelian logic, which is entirely theoretical and certainly not universal to all cultures. My point is, IQ tests don't measure intelligence; they measure your performance on IQ tests.

Which brings me to James Flynn's latest offering, What is Intelligence?: Beyond the Flynn Effect, and an excellent book review by Malcolm Gladwell in The New Yorker. It turns out that absolute IQ scores have been rising worldwide at a more or less constant rate of 3 points per decade—the so-called Flynn effect. By Gladwell's estimate:
If we go back even farther, the Flynn effect puts the average I.Q.s of the schoolchildren of 1900 at around 70, which is to suggest, bizarrely, that a century ago the United States was populated largely by people who today would be considered mentally retarded.

For IQ fundamentalists, this is not what you want to hear. Average IQ scores aren't supposed to change over time. In 1996, Herrnstein and Murray infamously asserted in The Bell Curve a racial hierarchy based on IQ statistical averages. James Watson, co-discoverer of DNA, recently attempted to lend credence to this claim by musing publicly that "all our social policies are based on the fact that their intelligence is the same as ours—whereas all the testing says not really" (ironically it turns out that Watson is about 12% black).

Flynn's central conclusion revolves around the idea of "cognitively challenging" environments, arguing that children brought up in such environments do better on things like IQ tests. It helps explain why children of German mothers and white or black American GIs fared similarly well on IQ tests, or why the performance of Southern Italian immigrants skyrocketed upon assimilation.

Cognitively challenging environments, like the advent of the media age, also help to explain why the most common IQ test, The Wechsler Intelligence Scale for Children (WISC), has been "updated" four times, each version slightly more difficult, in an effort to keep pace with the rising scores (we're currently on WISC IV). That said, one of the book's weaknesses appears to be an overuse of this phrase as a catch-all for any number of already verified beneficial factors, such as two-parent affluent households with access to books, etc.

All of this should not detract from Flynn's assertion that we need a better way to measure intelligence, and that it might not be possible to have a unified worldwide test. Given the importance attached to IQ tests (childhood stigma or criminal defense pleas), it's a crucial distinction. Thankfully, What Is Intelligence?, a result of 25 years of research, takes us a long way toward understanding the cultural underpinnings of intelligence measurements.

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