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I figured I'd step back today and answer some common questions about IQ.
Q. Is IQ really all that important in understanding how the world works?
A. In an absolute sense, no. Human behavior is incredibly complicated, and no single factor explains more than a small fraction of it.
Q. Why do you harp on IQ so much?
A. It's an underexploited market niche. The quantity and quality of writing in the Main Stream Media [MSM] on IQ and its effects is so abysmal that, simply by being informed and honest about IQ, I can explain how certain important things work that other journalists can't.
Q. What are IQ questions like?
A. They vary wildly. The nonverbal Raven Matrices look like the instruction manual for a DVD player from Mars. Some of the Wechsler questions look like the Word Power vocabulary quiz in the Reader's Digest.
Q. How can different questions give similar results?
A. They're validated to make sure they do a good job of predicting real world performance. Obviously, different tests are better at different tasks, such as testing small children, illiterates, or people who speak a different language, but, when used properly, all the major tests present similar results because they are proven predictors of actual behavior. ...
Q. Isn't character more important than intelligence?
A. I believe so. Work ethic, honesty, conscientiousness, kindness, together they're more important than intelligence. (Of course, when it comes to making money, less endearing personality traits like aggressiveness also play a big role, but we'll leave that aside for now.)
Can I quantify that? Well, that's where things get tricky…
Q. So why not test for work ethic and the like instead of IQ?
A. We do test for it, in many different ways. Consider the process of applying to college. The two most important elements in the application are high school GPA and the SAT or ACT score. The SAT and ACT are more or less an IQ test, while high school GPA is driven by a combination of IQ and work ethic.
But demonstrating work ethic via GPA is a time-consuming prospect for the applicant … and even for the admissions committee. The student spends four years in high school achieving a GPA, which he presents to the colleges to which he applies. But what does his GPA really say about him? Did he go to an easy school or a hard one? Did he take easy classes or hard ones? Does he have the brainpower to go far beyond high school material? These are complex questions, and it's no wonder that almost every college supplements GPA with the nationally standardized SAT or ACT.
Similarly, how does a would-be employee prove he's honest enough to handle large amounts of money? By slowly working his way up over the years from handling small amounts of money.
Q. Couldn't somebody invent paper and pencil tests to measure character?
A. They have. They're pretty accurate … overall.
On the other hand, these tests haven't been all that popular, perhaps because they are liable to occasional catastrophic failures. The danger is that somebody with a high IQ but poor character would use his smarts to figure out what answers on the test would make him sound like the second coming of George Washington. And a high-IQ scoundrel is the last person you want to select.
You could call it the Ahmad Chalabi Problem. The Iraqi convicted embezzler with a Ph.D. in math from the
U.of Chicagoused his enormous brainpower to figure out how to dupe the neocons into believing that he literally was the George Washington of Iraq, so should invade his homeland to make him president. America
In contrast to character tests, the good news about IQ tests is that they are un-outsmartable. If you can use your brain to figure out what answers the test makers want, well, then you have a high IQ.
Q. So, do IQ tests predict an individual's fate?
A. In an absolute sense, not very accurately at all. Indeed, any single person's destiny is beyond the capability of all the tests ever invented to predict with much accuracy.
Q. So, if IQ isn't all that accurate for making predictions about an individual, why even think of using it to compare groups, which are much more complicated?
A. That sounds sensible, but it's exactly backwards. The larger the sample size, the more the statistical noise washes out.
Q. How can that be?
A. If Adam and Zach take an IQ test and Adam outscores Zach by 15 points, it's far from impossible that Zach actually has the higher "true" IQ. A hundred random perturbations could have thrown the results off. Maybe if they took the test dozen times, Zach just might average higher than Adam.
But for comparing the averages of large groups of people, the chance of error becomes vanishingly small. For example, the largest meta-analysis of American ethnic differences in IQ, Philip L. Roth's 2001 survey,[Ethnic group differences in cognitive ability in employment and educational settings: a meta-analysis, Personnel Psychology 54, 297–330] aggregated 105 studies of 6,246,729 individuals. That's what you call a decent sample size.
Q. So, you're saying that IQ testing can tell us more about group differences than about individual differences?
A. If the sample sizes are big enough and all else is equal, a higher IQ group will virtually always outperform a lower IQ group on any behavioral metric.
Of course, everything else is seldom equal. A more conscientious group may well outperform a higher IQ group. On the other hand, conscientiousness, like many virtues, is positively correlated with IQ, so IQ tests work surprisingly well.
Q. Wait a minute, does that mean that maybe some of the predictive power of IQ comes not from intelligence itself, but from virtues associated with it like conscientiousness?
A. Most likely. But perhaps smarter people are more conscientious because they are more likely to foresee the bad consequences of slacking off. It's an interesting philosophical question, but, in a practical sense, so what? We have a test that can predict behavior. That's useful.
Q. Can one number adequately describe a person's intelligence?