Manhattan Bridge under construction-1909

Intelligence Testing & IQ: What it is, isn’t

Forrest ChristianLearning 3 Comments

I’ve been studying the world of “intelligence testing” for some work I’m doing. Other than my own experience as a small child being subjected to what I recall as two days of evaluation far from my home (actually i had a lot of fun and my mother recalls it as only a few hours), I really knew almost nothing about the world of “Intelligence Quotients” (IQ) and intelligence testing.

I just assumed it was a load of horse droppings, after years of being told that IQ doesn’t correlate with anything and is not a real measure.

Boy was I surprised by the truth. It turns out that intelligence testing, unless you’re a psychometrician, is different from what you have been taught.

WARNING! WARNING That means that almost everyone one of us has intelligence testing wrong, critics and supporters

First, intelligence testing is not.

What Intelligence Testing / IQ Isn’t

Cat intelligence test. Licensed through

Cat IQ Test

  • “IQ”, at least any more. In the old days intelligence tests were for kids measured a “mental age”, which was actually calculated by a quotient. Hence “intelligence quotient” and “IQ”. Not any more. They’ve not been quotients for years.
  • Poor supported. Intelligence tests are pretty good at measuring whatever it is that they measure. This “general mental ability” (GMA) is pretty much consistent with what Binet had thought it was a long time ago. Which is pretty amazing.
  • [NOTE: I’m going to use “general mental ability” and “GMA” to mean what most people mean by “intelligence”. And I’ll explain why.]
  • Unfounded in cognitive theory. For about thirty years, the intelligence testing industry has been churning out tests that rely on the ideas of “fluid intelligence” (kind of raw processing horsepower, but see below) and “crystalized intelligence” (kind of what you know; again see below). The theory has been tied to neurological science, so we know a great deal more than we did before. Alan Kaufman (creator of the K-ABC instrument) has a terrific overview of the issues in IQ Testing 101 (Psych 101)
  • Unpredictive of performance. GMA matches up with performance on the job.It’s not incredibly strong but it’s a solid predictor, especially if you get a good test and measure that “fluid intelligence”. It also predicts a bit of school performance, health, wealth, etc. There’s even been a study that showed a correlation with “attractiveness”. So GMA correlates with lots of good things. Just not real tight.
  • Something you take online. A real intelligence test requires a trained psychologist and they take a long time. Although the SAT and GRE correlate with GMA a bit.
  • A real measure of what we mean by “smart” in the US or “clever” in the UK. Keith Stanovich points out that people who score high on intelligence tests are not necessarily better at making wise decisions. At the same time, he believes that “IQ tests” measure something real today: General Mental Ability. (See What Intelligence Tests Miss: The Psychology of Rational Thought)
  • Measure what’s important in leadership. The General Mental Ability (GMA) measured by intelligence tests just is not what we all need in leadership. The US has a couple of national leadership examples of men with high IQ scores (from armed services enlistment or school tests) that were more than a standard deviation from average but who were still uninterested, uncurious, unreflective, dolts. It also has a couple of guys with close to average IQ scores who were superior leaders.
  • Good leadership kind of does require what higher fluid intelligence scores bring. In a different angle, Owen Jacobs commented in a talk at the 2007 GO Society conference in Toronto that the Army’s best leaders were people who read. A lot. And “far afield”. These people read almost everything. They were constantly shoving new learning and ideas into their heads. This behavior correlates pretty strongly with higher fluid intelligence scores, at least in people before middle age. I’m not sure which way it goes, though: does the voracious reading lead to higher scores, or does having all that fluid intelligence just make you more curious and reading is the best way to solve it.

That’s pretty different from what I had always heard.

Next time, let’s look at the problems of intelligence testing and the theory behind it. It may not be false, but it’s not everything either. There are issues of tied up in the Great Rationality Debate, the earlier Cognitive Complexity Controversy, and the Talent War.

Sounds exciting, doesn’t it? Next time.

Manhattan Bridge under construction-1909. Library of Congress

Comments 3

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  3. Forrest,

    Thought-provoking post. I know you have some more thoughts percolating so I look forward to the follow-up post.


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