Is there anything to IQ?

“IQ tests just measure how good you are at doing IQ tests”. We’ve all heard this argument: it’s almost always made when intelligence testing is mentioned. It’s often made by people who are, otherwise, highly scientifically literate: you wouldn’t catch them arguing that climate change is a myth or that vaccines might cause autism. But saying that IQ tests are useless is just as wrong as these notions: in fact, decades of well-replicated research point to IQ tests as some of the most reliable and valid instruments in all of psychological science.

So what does an IQ test—which might consist, for example, of shape-based puzzles, timings of how quickly you can check through lists of meaningless symbols, memory tests, and vocabulary measures—actually tell you? The strongest relation is perhaps unsurprising: an IQ score is highly predictive of how people will do in school. One huge study found that IQ scores at age 11 correlated .8 (on a scale of -1 to 1) with school grades at age 16. Surely this gives us some basis for calling these measures ‘intelligence tests’. But that’s just the beginning: higher IQ scores are predictive of more occupational success, higher income, and better physical and mental health. Perhaps the most arresting finding is that IQ scores taken in childhood are predictive of mortality: smarter people live longer, and this association is still there after controlling for social class. So much for “just how good you are at IQ tests”.

Neuroscientists and geneticists have also made good progress in understanding human intelligence. Meta-analyses of hundreds of studies confirm that people with larger brains tend to get higher scores on IQ tests, and research on more specific brain regions and features continues apace. We know from studies of twins, and from studies done directly on DNA, that intelligence test scores are heritable: that is, many of the intelligence differences between people are due to genetics. We’ve just begun to find some of the specific genes that might be responsible for these differences.

Because it has been linked to genetic and neural features, and because it seems highly stable across the lifespan, people make the mistake of assuming intelligence is immutable. Your IQ score, they think, is set in stone, condemning you to a poorer life if it’s below-average. But this is a mistake: there’s nothing in principle to suggest we can’t raise people’s IQ scores, at least to a degree (though many recent attempts to do so have been non-starters). Indeed, IQ scores have been rising inexorably across the years, in a process called the Flynn Effect, for (non-genetic) reasons that aren’t yet clear. Another mistake is to think that anyone has ever claimed that an IQ score ‘sums up’ a person; this is another falsehood, since all IQ researchers would readily admit that personality, motivation, and a host of other factors—including luck—are all critical for success in life.

It would be foolish to deny that there are any skeletons in IQ testing’s closet. Many (though by no means all) of the originators of the tests were involved with the eugenics movement in the early 20th Century, and it’s absolutely reasonable to be appalled at some of the uses to which IQ tests were originally put. But these concerns are irrelevant to the main question of whether an IQ score, taken today, can tell you anything about a person: facts are facts, and the validity of intelligence test scores is amply backed by voluminous evidence.

As all the studies linked above show, IQ tests are useful in a wide variety of situations, from education to medicine to the world of work. We need IQ tests to help us understand how the brain ages, and how we might be able to help it do so more healthily. We need IQ tests to help us work out how to boost people’s intelligence, and thus to boost their productivity. Perhaps above all, IQ tests are one of the tools with which psychologists can dissect and examine human intelligence: we’d be extremely unwise to continue to ignore their insights.

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You can read more about the science of intelligence and IQ in my new book, Intelligence: All That Matters, published on June 18 by Hodder & Stoughton.

In terms of an IQ test, why is the amount of time you have on the test

so important ?

After all, if I can reach the correct conclusion after five minues of thought

and you cannot reach it after two hours, does that not say something about my abilities. But why should someone who solves it or guesses

it after three minutes be given full credit and I, because I ran out of time

be given no credit.

The SAT Exam in America is notoriously time driven.

Each part of the exam is timed so if you dawdle you are lost.

Yet does that not meant that those who provide quickly thought out

answers do better than those who ponder the answer.

In short does our modern Stock Market where quickness is rewarded

with massive amounts of short-term gains endanger the economy ?

Whatever happened to investing for the long run and for dividends ?

Ed, if it were, I’d be labeled, like Motivation Speaker Les Brown was during his youth, “educable, mentally retarded.” I soared in some areas–and tests–and crashed and burned in others. Acceptance of weaknesses(and failings) is one of the keys to wisdom.

I am a member of MENSA, so by my acions I implicitedly believe there is something to IQ. Those with higher IQ’s tend to process information more rapidly and reason more clearly. This however has nothing to do with wisdom, which is a whole different issue. Each person has differing capacities to learn and retain and like RAM in a computer—actively hold and use their intelligence. IQ tests are the most reliable means of imperfectly measuring this.

It seems to correlate with high intelligence.

I doubt that a good IQ test can be questioned on its ability to find smart or gifted individuals, especially with the accuracy they have shown.