July 19, 2007


IQ for economists: After trying hard for half a decade to completely ignore the data set on average national IQs in Lynn & Vanhanen's IQ and the Wealth of Nations, economists are now starting to attack it, albeit with embarrassing results.

For the next generation of economists who might be looking around for something important but vastly underexploited to analyze, let me review a key point. The nature vs. nurture arguments about IQ can be a distraction because they aren't all that relevant for your purposes. What is important for economists is the stability of national and group average IQ scores. If they have zoomed all over the place relative to each other, they don't have much explanatory power about how we've gotten to where we are. And if they are likely to change quickly and unpredictably over the next few years, why bother worrying about them?

For better or worse, however, we can be confident that differences in average group IQ are going to be around for a long time.

The relative gaps among groups have been fairly stable for several generations. East Asians may have picked up a few points on everybody else over the last 40 or 50 years, and Maoris in New Zealand may have done the same (although New Zealanders tell me that may just be mixed race people reclassifying themselves to get affirmative action benefits), but otherwise, remarkable relative stability is the norm.

One of Lynn's recent books, for instance, lists 620 IQ studies of different groups going back, in a few cases, to the first quarter of the 20th Century. I've created a graph showing that there has been no overlap of average scores among Japanese (23 studies in red), Hispanics in America (17 studies in green), and Australian Aborigines (17 studies in blue).


The Japanese have consistently scored somewhere around 105 on a scale where white American are pegged at 100, Hispanics in the U.S. at about 90 (which, by the way, is roughly the world average), and Australian Aborigines at very low levels.

I don't know what causes differences in average IQ, but the evidence is overwhelming that they were stable enough over the 1950-2000 era to be used in studies, and, with almost as much assurance, that they will be stable enough over, say, the 2000-2030 era to be important to study for the future.

If a gap between two groups suddenly disappeared in all the babies being born tomorrow for some magic reason, the gap among the workforce wouldn't begin to shrink until 2025 and wouldn't disappear until 2072.

So, the current realities demand far more study than they've gotten from the economics profession.


My published articles are archived at iSteve.com -- Steve Sailer

30 comments:

Anonymous said...

It's not just economists: the humanities in general have a crypto-religious view of human nature, i.e., that it floats free of biology. The idea that the genetically mediated electro-chemistry of the brain has any bearing at all on GDP or Shakespeare's sonnets or female under-representation in maths and physics simply doesn't occur to many people. Brains, being hidden inside skulls, simply escape their notice.

Ron Guhname said...

People wrongly assume that if something is caused by the environment, then that means we can easily fix it. I doubt that genes had much to do with the recalcitrance that the Romans experienced from the early Christians, but it was not easy to get rid of nevertheless.

Even if national differences in IQ were 100% socially caused (and I'm sure they are not) how do you turn a nation of people who are indifferent to formal education to a nation of people who are motivated to sacrifice almost two decades of their lives to school?

Assuming Hispanic IQs were culturally determined, your figure shows that nobody has been able to close the gap in almost a century of pushing education.

Karl Smith said...

As a young economists studying human capital, poverty and growth I tend to agree.

We may not know exactly what IQ is or the extent to which it is influenced by genetics or environmental pressures.

However, neither of those questions is important. What matters is that it predicts poverty.

Even if IQ is caused by poverty that is important because it means we have yard stick by which to measure our anti-poverty efforts early in a child's life.

The only case in which we should be unconcerned about IQ is if we were convinced that

A) It is 100% genetic

B) There is no social policy that can effectively alter allele frequency.

Otherwise, social policy that might increase IQ is extremely important.

Anthony said...

The problem with using IQ for comparative studies is that economic performance of identifiable groups and countries has varied all over the place, and the statistics on them are notoriously unreliable for certain countries and periods in history.

Were the Chinese significantly lower in IQ in the Mao era? Were the Japanese less smart through the late 1990s?

Were there identifiable IQ differences between Germans in East and West Germany? How fast did the East German economy really grow?

Policies and social factors have a very large, and hard-to-identify, effect on economic growth rates, and some very smart people fall for some very dumb policy ideas.

Anonymous said...

the mean IQ in spain is above 90. any other reference to hispanics is invalid and should be thrown away. readers should ignore steve's data on "hispanics". the data means nothing and is irrelevant.

as far as fake "hispanics" go, it is impossible to both integrate them and still call them "hispanics". the very act of integrating them destroys anything that is "hispanic" about them.

steve really has a problem here. maybe he should start counting all black americans as white americans. they speak english after all. that would make as much sense as steve's system for "hispanics".

Anonymous said...

anybody can see that the mean IQ in "hispanic" nations varies rather greatly. and consequently, so does the per capita GDP. in fact, we can link to pages on steve's own site:

http://www.isteve.com/IQ_Table.htm

which discredit his idea that there is a "hispanic" race.

what causes those IQ and income differences steve? do different dialects of spanish cause IQ to go down?

why is the mean IQ in england different from the mean IQ in jamaica? they both speak english, aren't they the same race? don't they have the same genes? or does jamaican english just make people dumber?

Anonymous said...

The numbers for aboringinal Australians are astounding. Assuming that they are correct, the average Aborigine is mentally retarded. It's sad and almost creepy to imagine an entire civilization of human beings functioning at such a low level of intellect and child-like reasoning capacity. (And they're not even Hollywood celebrities!)

I can only assume that this issue is never, ever, EVER discussed publically in Australia. Any Australians out there? I'd be interested in their POV on this.

Anonymous said...

It would be interesting to look at IQ and support for free trade. I am afraid that US immigration policy is going to lead us to protectionism for two reasons -- the press blaming free trade for the negatives brought about by immigration, and immigration is dumbing down the US.

Anonymous said...

"I can only assume that this issue is never, ever, EVER discussed publically in Australia."

Well, the Prime Minister of Australia just announced he was cutting off porn and alcohol privileges for six months for aborigines living on federal lands (in response to an epidemic of child sex abuse).

Anonymous said...

Return of the fallacies.

Tyler Cowen starts it all off by appealing to an anecdote. Then there are the assumptions of theoretical human potential that Ron Guhname mentions, rubric arguments (economic development somehow increases IQ), and horrible view accusations (fustercluck's 'master race' comment).

Alex Tabarrok even breaks out Occam's Butterknife: why attribute to a single variable like IQ what you can instead attribute to ten unweighted variables as determined by the Heritage Foundation?

Anonymous said...

Jody. The horse? She is dead.

Anonymous said...

Approaching national IQ from the stance of dealing with a population of immigrants from low performing countries, I think the solution lies in an incremental approach. This assumes we are going to address the issue of low IQ populations as a society. Part of the problem is in our public schools. Attempts to transform every student into an Einstein with a "free and appropriate education" are misguided at best. The teachers and administrators know most of their students aren't going to be doctors, lawyers, physicists, etc. Yet we play a high stakes game by educating everyone as if they will be high level professionals. The situation is made more impossible by the fact that we are trying to educate an ever growing population of students from countries with relatively lower average IQ scores.

I know I've worked in high schools where every student had to take physics and calculus. This must be part of the basic requirements now. Not every student has an aptitude for math at that level but most can do bookkeeping very well. We also have an epidemic of financial illiteracy that leaves many Americans in serious debt. These kids manage to pass what is probably dumbed down physics but can't calculate how much they will end up having to pay in interest on credit card debt or how long it will take to pay it back. Why not be realstic and teach students subjects that will benefit them, business math for instance?

Political correctness is responsible for some of the inappropriate curriculum choices but I know this started way back when I was in high school. I think the source was government concern that American students weren't keeping up with the communists - then they started systematically raising the bar in the math & sciences despite the fact that students weren't necessarily meeting the new goals. Meanwhile, it became almost taboo to track students into work related programs because everyone deserves a chance at the brass ring.

Take the two 17 year olds from the article. They aren't demonstrating an ability to reason at an abstract level and probably won't. Though there are more jobs (jobs that pay well enough to keep these two in the middle class) out there that don't require much abstract reasoning than those that do, these two kids would most likely be expected to take courses that won't benefit them in any way (unless they qualify for the magical Learning Disabled loophole). They will probably be bored and frustrated with the content. The drain of having to do the herculian task of passing a very abstract math course might even detract from their performance in other courses.

In the end, we end up emphasizing the "free" part of "free and appropriate education" which wastes money and effort. The effort to rescue that one child from the supposed inequity that keeps him out of med school is typical of our society. A parallel is those ridiculous women who get pregnant with multiples via the unnatural means of fertility drugs then insists on trying to carry an inhuman number of embryos to full-term. Another is the "we have room for everyone" approach to immigration. We refuse to make hard decisions in this country.

Anonymous said...

Cowen may be skeptical, but give him credit. He and his department DID hire G. Jones. And knowing the way academic hiring works, someone of his stature had to support the appointment.

Anonymous said...

I know people who have worked and traded regularly with Aborigines.

From what I remember of the conversation I had with him about it, they'd have difficulty distinguishing amounts greater than a certain quantity (maybe 2 or 3?).

Also, when he was recording a transaction, they wouldn't understand a canceling entry - you had to physically cross out the old entry to satisfy them that you weren't ripping them off.

One other thing I remember from someone who grew up in their schools as the only White boy in the school. He learned how to defend himself very well because fights often came to him.

He said that if you got into an altercation with one, you should never, ever, punch an aborigine anywhere in the head (e.g. aim for the stomach). The skull is too thick, you will hurt your hand and you won't affect the aborigine at all.

At the time, I was loath to believe him. I preferred to believe Diamond and my own college upbringing than to believe the lying eyes of my own friends and acquaintances.

I think it's partly an Australian thing in general - the continent is so isolated that the competition is pretty poor compared to the rest of the world. When you consider that anything from mammals on up to primitive humans could only get there by traveling across land bridges thousands of years ago, and even if they did, something suited to Northern European climates has to brave the tropics in New Guinea and Northern Australia before even making it to the more temperate regions.

Most of Australia's animals are not going to hold their own outside of the island continent. The possible exception might be the brushtail possum - I think it has been introduced to the USA, and is at least holding its own there.

Anonymous said...

Well, perhaps it was inevitable. Dr. Cowen "pulled a DeLong" and flushed 260+ inconvenient comments down the memory hole.

- J. Malloy

Anonymous said...

Uh, yeah, then maybe you should go back to Diamond, since bone density (IE in this case, aboriginals having skulls twice as thick as europeans on average) have varying heritabilities.

Why do you people latch onto these physical traits as being so deep-seated?

Jesus where do you people come from on this? You act like aboriginals aren't even human beings, they're just a variant of melanisian, whom are nothing more than african-looking southeast asians. Their skull and brain size estimates suggest something in the 70's, not the retarded animals you cretins paint them as.

Anonymous said...

Well, it looks like the hecklers have vetoed the realistic discussion of IQ and economic development over on Professor Cowen's blog--he's taken down the comment thread because it turned "nasty." I had been watching it and I can certify that the IQ realists weren't the nasty ones.

Doug1 said...

Jody said:
the mean IQ in spain is above 90. any other reference to hispanics is invalid. *** steve really has a problem here. maybe he should start counting all black americans as white americans. they speak english after all. that would make as much sense as steve's system for "hispanics".

You’re either being obtuse, are woefully uninformed, or are less than intelligent.

The only group of “Hispanics” in America who are overwhelmingly of Spanish Caucasian extraction are the Cubans who came before the Mariel wave, which is most of them. They were by and large from Cuba’s upper and upper middle classes and fled the island after it became apparent that Castro was or had turned Communist rather than leftist democrat, which is what most had previously believed. They are also the group of Hispanics who have done the best in this country and in fact now do as well as the non Cuban white population, perhaps better on average.

The Mexicans and Central Americans who today predominate in Hispanic immigrants to everywhere but New York and make up the great majority of the “Hispanic” ethnicity nationwide, are drawn from the lowest classes of those societies by and large and are heavily Indio (Native American) in racial background.

Doug1 said...

Essex said:

The numbers for aboringinal Australians are astounding. Assuming that they are correct, the average Aborigine is mentally retarded.

Well, mostly yes but some no. We associate mentally retarded people with slow and stumbling speech, often with an uncoordinated style of walking, and the like. That’s symptomatic of either the severely mentally retarded or retardation as a result of some genetic or other defect that affects more than “just” abstract reasoning ability. Not all retarded people are like that. Some have very outgoing and verbal personalities. Certainly most Africans who score in the below 70 “retarded” range are not like that, as Rushton explains in a very interesting VDare Article. I highly recommend it.

Unknown said...

By Ron Guhname, at 7/20/2007 5:21 AM

Well said. I've argued with way, way more than my share of screeching radical environmentalists, and none of them has ever had an answer for this. The causes of black failure* are a mixture of nature and nurture, but even if you insist they're all nurture, they're persistent.

Who cares whatcha callit? It sticks to blacks and doesn't seem curable.

* Always a relative term; by black standards blacks are a runaway success. :)

Anonymous said...

We may not know exactly what IQ is ...

No, wrong. IQ is what IQ tests measure.

Average group IQ also correlates positively with correlation coefficient greater than 0.50 with average group success in the modern world.

... or the extent to which it is influenced by genetics or environmental pressures.

So your position boils down to the standard lieberal cant that we must hope for the best and assume all differences in cognitive performance are due to nurture and environment.

Anonymous said...

Anonymous 4:29:

"I know I've worked in high schools where every student had to take physics and calculus. This must be part of the basic requirements now. Not every student has an aptitude for math at that level but most can do bookkeeping very well. We also have an epidemic of financial illiteracy that leaves many Americans in serious debt. These kids manage to pass what is probably dumbed down physics but can't calculate how much they will end up having to pay in interest on credit card debt or how long it will take to pay it back. Why not be realstic and teach students subjects that will benefit them, business math for instance?"

I agree that basic financial literacy should be taught in high school (it could be folded into math curricula), but schools shouldn't stop teaching basic, algebra-based physics. The rudimentary knowledge of mechanics, electricity, and other subjects are useful not just to college-bound future engineers but also to future electricians, mechanics and other skilled tradesmen.

This discussion though reminds me of a recent ad in the WSJ by the steel company Nucor (reproduced on the company's website here) where the company brags that all of its employees' children will get scholarships to go to college. What would be wrong with some of their children growing up to be steel workers at Nucor? It seems to be a pretty good job, the way the company describes it. Why pressure all of them to go to college?

Anonymous said...

dougjnn wrote:

We associate mentally retarded people with slow and stumbling speech ... Not all retarded people are like that. Some have very outgoing and verbal personalities. Certainly most Africans who score in the below 70 “retarded” range are not like that, as Rushton explains in a very interesting VDare Article. I highly recommend it.

An excellent article indeed. Thanks for the link. I see the point that, whereas a European with an IQ of 60 has something wrong with him, an Aborigine with the same IQ has mental development that is normal for his race. This implies a higher level of functioning in the Aborigine than a mentally retarded white person. It's still a pretty low level of functioning, though.

Since we're talking about indigenous peoples, what is the average IQ of American Indians?

Fred wrote:

What would be wrong with some of their children growing up to be steel workers at Nucor?

There's nothing wrong with it, per se , but it lacks the economic prospects that can come with a college degree. As you've probably noticed, steel is not exactly a growth industry in the US, and factory jobs of any kind are fewer and poorer paying than ever.

The rudimentary knowledge of mechanics, electricity, and other subjects are useful not just to college-bound future engineers but also to future electricians, mechanics and other skilled tradesmen.

I agree, but these jobs are not equivalent to being a steelworker. They require a minimum of average intelligence - at least any electrician who works on my house does - and are blue-collar service jobs (well-paid ones at that) rather than factory jobs. Furthermore, you can import 100% of your steel, but it's hard to fly a guy here from China to fix your plumbing. There will always be a need for skilled tradesmen, but these jobs are no substitute for the kind of assemply-line work that used to employ the 50% of population with lower-than-average intelligence. That loss seems to have no solution. Maybe we could export our less intellectually gifted citizens to Mexico.

Anonymous said...

American Indians seem to have a quite noticeable correlation between latitude and intelligence. In fact according to some tests there's as much difference in IQ between Eskimos and Andeans as there is between whites and blacks. But I personally am a skeptic. The only IQ gap I believe in is the white-black one and only because it has been shown to be real again and again on hundreds of tests whereas most of the others mentioned in books like the Bell Curve rest on pretty arbitrary interpretations of evidence, in my opinion.

Anonymous said...

Furthermore, you can import 100% of your steel, but it's hard to fly a guy here from China to fix your plumbing. ...

But it's EZ to hire a Mexican to do the work cheaper. No need to fly him in.

... Maybe we could export our less intellectually gifted citizens to Mexico ...

Good idea. We also should look into establishing penal colonies in Afghanistan and maybe Iraq.

Karl Smith said...

No, wrong. IQ is what IQ tests measure.

On one level this is of course true and I argue this in the debate on "bias."

However, presumably there is some tangible difference between low and high IQ individuals.


This gets a little dicey since we are dealing with the mind, but I am at least comfortable with the maintained hypothesis that mental differences are reflected one-to-one in material differences.

That is, the mind exists as a material thing. In that case, we would expect some material analog to IQ. However, we are uncertain about what that material phenomenon is.

So your position boils down to the standard lieberal cant that we must hope for the best and assume all differences in cognitive performance are due to nurture and environment.

Well, I don't know about that.

First, I think the IQ function as would call it is an important research area. There is certainly strong evidence that genetics is involved in the function.

Second, I don't think the policy paradigm your addressing is correct.

I understand that many people are concerned about whether or not IQ is heritable because they are concerned about ranking races or ethnicities.

This is of little concern to me and I believe of almost no policy significance. We can measure individual IQ at a fairly low cost. If we want to have an IQ policy then we can do it without regard to race or ethnicity.

A lot of people seemed to be concerned over what this implies for racism/discrimination. However, this again is a red-herring.

It is entirely consistent to say that racial difference in IQ are completely determined by environment and that racism play no part whatsoever.

It is also consistent and indeed likely that if racial differences in IQ are completely genetically determined that minority groups suffer from racism.

It think it is hard to imagine that there are genetic differences in racial IQ averages AND there is no racial discrimination.

You would have to argue that people consistently either mis-estimate or disregard a low cost source of information.


My larger point is this:

Suppose that IQ independently correlates for GDP per capita. Then we have an important lever for attacking global poverty. Unless we believe that there is no environmental component we should focus on efforts that would tend to raise IQ.

Even if IQ does not cause GDP growth, independent correlation would suggest that factors which cause IQ growth also lead to economic growth, which is what really matters.


As a side note. I think that it is cute how rapidly so many people in the blogosphere jump on the idea that high IQ causes growth.

My guess is that most of these people have high IQs.

There is a strong tendency for people to believe that whatever characteristic they have in abundance is key for economic growth.

Those with high labor supply say hard work, entrepreneurs say willingness to accept risk, and smart people say intelligence.

The truth is that much of it is probably miserliness. Intelligence, hard work and risk taking are nice but capital is key.

Anonymous said...

Jesus where do you people come from on this? You act like aboriginals aren't even human beings, they're just a variant of melanisian, whom are nothing more than african-looking southeast asians. Their skull and brain size estimates suggest something in the 70's, not the retarded animals you cretins paint them as.

Maybe a little off-topic, but I just noticed this story in the news:

11-Year-Old Gives STD to Two Preschool Girls
By Tony Barrass
July 23, 2007 01:15am
news.com.au
freerepublic.com

• Boy 'forced young girls into sex with him'
• Girls contracted sexually transmitted diseases
• Police say matter is health issue, not criminal

AN 11-year-old boy forced two pre-school-aged girls to have sex with him, infected them with sexually transmitted diseases, but will not be prosecuted by Western Australian authorities.

Police yesterday confirmed that criminal charges would not be laid against the boy from Balgo, a troubled indigenous community in the northeastern reaches of the Great Sandy Desert 100km from the Northern Territory border, despite his being above the age of criminal responsibility under state law...

Anonymous said...

The truth is that much of it is probably miserliness. Intelligence, hard work and risk taking are nice but capital is key.

Everyone takes pride in their most salient virtue. I can see that you're no exception.

Karl Smith said...

Everyone takes pride in their most salient virtue. I can see that you're no exception.

Have you been talking to my wife? ;)

Anonymous said...

If IQ is a function of poverty rather than genetics there should be dozens or hundreds of readily available correlation studies proving the point. So come on you folks who subscribe to the poverty causes low IQ theory, lets see all those correlation studies. Make sure to include those that were done in extremely poor communities in east China.I'll check back later for the sources.