September 14, 2007
The Waning of I.Q.
By DAVID BROOKS
A nice phenomenon of the past few years is the diminishing influence of I.Q.
For a time, I.Q. was the most reliable method we had to capture mental aptitude. People had the impression that we are born with these information-processing engines in our heads and that smart people have more horsepower than dumb people.
And in fact, there’s something to that. There is such a thing as general intelligence; people who are good at one mental skill tend to be good at others. This intelligence is partly hereditary. A meta-analysis by Bernie Devlin of the University of Pittsburgh found that genes account for about 48 percent of the differences in I.Q. scores. There’s even evidence that people with bigger brains tend to have higher intelligence.
But there has always been something opaque about I.Q. In the first place, there’s no consensus about what intelligence is. Some people think intelligence is the ability to adapt to an environment, others that capacity to think abstractly, and so on.
Then there are weird patterns. For example, over the past century, average I.Q. scores have risen at a rate of about 3 to 6 points per decade. This phenomenon, known as the Flynn effect, has been measured in many countries and across all age groups. Nobody seems to understand why this happens or why it seems to be petering out in some places, like Scandinavia.
I.Q. can also be powerfully affected by environment. As Eric Turkheimer of the University of Virginia and others have shown, growing up in poverty can affect your intelligence for the worse. Growing up in an emotionally strangled household also affects I.Q.
One of the classic findings of this was made by H.M. Skeels back in the 1930s. He studied mentally retarded orphans who were put in foster homes. After four years, their I.Q.’s diverged an amazing 50 points from orphans who were not moved. And the remarkable thing is the mothers who adopted the orphans were themselves mentally retarded and living in a different institution. It wasn’t tutoring that produced the I.Q. spike; it was love.
Then, finally, there are the various theories of multiple intelligences. We don’t just have one thing called intelligence. We have a lot of distinct mental capacities. These theories thrive, despite resistance from the statisticians, because they explain everyday experience. I’m decent at processing words, but when it comes to calculating the caroms on a pool table, I have the aptitude of a sea slug.
I.Q., in other words, is a black box. It measures something, but it’s not clear what it is or whether it’s good at predicting how people will do in life. Over the past few years, scientists have opened the black box to investigate the brain itself, not a statistical artifact.
Now you can read books about mental capacities in which the subject of I.Q. and intelligence barely comes up. The authors are concerned instead with, say, the parallel processes that compete for attention in the brain, and how they integrate. They’re discovering that far from being a cold engine for processing information, neural connections are shaped by emotion.
Antonio Damasio of the University of Southern California had a patient rendered emotionless by damage to his frontal lobes. When asked what day he could come back for an appointment, he stood there for nearly half an hour describing the pros and cons of different dates, but was incapable of making a decision. This is not the Spock-like brain engine suggested by the I.Q.
Today, the research that dominates public conversation is not about raw brain power but about the strengths and consequences of specific processes. Daniel Schacter of Harvard writes about the vices that flow from the way memory works. Daniel Gilbert, also of Harvard, describes the mistakes people make in perceiving the future. If people at Harvard are moving beyond general intelligence, you know something big is happening.
The cultural consequence is that judging intelligence is less like measuring horsepower in an engine and more like watching ballet. Speed and strength are part of intelligence, and these things can be measured numerically, but the essence of the activity is found in the rhythm and grace and personality — traits that are the products of an idiosyncratic blend of emotions, experiences, motivations and inheritances.
Recent brain research, rather than reducing everything to electrical impulses and quantifiable pulses, actually enhances our appreciation of human complexity and richness. While psychometrics offered the false allure of objective fact, the new science brings us back into contact with literature, history and the humanities, and, ultimately, to the uniqueness of the individual.
I couldn't agree more! Obviously, judging from laws like No Child Left Behind, our political and pundit classes have spent quite enough time studying and publicly elucidating the subtleties of the science of IQ. C'mon, guys, enough is enough with all the IQ expertise on display in the press! We're into diminishing marginal returns on IQ knowledge by now.
Aren't we all sick of hearing George Will and Thomas Friedman harp on and on about Spearman's Hypothesis about the g factor on every Sunday morning talk show? And how many dozens of articles about IQ and the Wealth of Nations can The Economist run in one decade? And by now haven't we've all heard NPR explain ad infinitum that the reason that young whites have an 80% higher combat death rate in the Iraq War than young minorities is in large part because the military's well-validated devotion to IQ testing makes it much harder for minorities, with their lower average IQs, to enlist? And do we really have to see Arthur Jensen and Linda Gottfredson on the evening news every week being asked to give an IQ expert's perspective on every social issue under the sun? Can't we ever debate immigration without Dana Milbank of the Washington Post reminding us of the lower average IQ of illegal immigrants?
And when will critics of IQ research ever get any media attention whatsoever? Will the little-known paleontologist Stephen Jay Gould, who died in poverty because of persecution by the all-powerful IQ Establishment, ever get any recognition for his (admittedly obscurantist) critique of IQ?
And when will all the Schools of Education stop requiring all future teachers to spend a semester studying The Bell Curve? Wouldn't 8 weeks be enough to spend on that one book?
Brooks is right! Enough of the never-ending IQ-this and IQ-that in the media!