Intergroup variations in IQ


The Jason Richwine dissertation, like its predecessor The Bell Curve in 1994, argued that IQ scores are a good proxy for intelligence, that intelligence has a substantial hereditary component and is thus largely immutable to change by external measures, and that high IQ levels are significant predictors of economic and social success in life while low levels predict a life of crime, unemployment, and general failure. According to Richwine, American Hispanics have average IQs around 89 (the overall average is fixed to be 100) and thus Hispanic immigrants will be a drain on society. (See here and here for earlier posts on this.)

There are some problematic assumptions that go into arriving at this conclusion. First of all, ‘race’ as a biological construct has been largely abandoned because it has no clear and unambiguous identifying markers. Race is now viewed largely a sociological construct and people self-identify as to what ‘race’ they belong, if they wish to do so. Skin color, language, nationality, and culture are easier to distinguish and are sometimes used as proxies for race.

Second, what constitutes intelligence is itself something that is difficult to get agreement on since our intuitive notion of it takes many forms. What we have are IQ tests. All such tests measure something but what that thing is is not always clear. There are many batteries of such tests that measure different sets of skills and what psychometricians do is take those test results and do something called a a factor analysis on them and get a quantity known as ‘Spearman’s g’ that gives the degree of inter-correlation among those results and is assumed to measure something called general intelligence.

There are many IQ tests that are used, of which three are most common. The Raven ‘s Progressive Matrices are logic-based tests that require people to identify the missing piece of a design. It deals entirely with patterns involving shapes and so no language enters. This test is said to measure fluid intelligence or the ability to solve problems quickly. There are other tests such as the WISC (Wechsler Intelligence Scale for Children) and the WAIS (Wechsler Adult Intelligence Scale) that are said to measure crystallized intelligence, what you supposedly need in order to be able to acquire various kinds of knowledge. The Wechler tests consists of ten subtests, some of which measure verbal skills and others that involve symbols. All these tests have different ‘g-loadings’, meaning that the size of their correlations with Spearman’s g differs. The result of any given IQ test can be used taken to be a proxy for this g-factor and thus a measure of intelligence. (See James R. Flynn, Are We Getting Smarter? (2012), p. 7.)

To get a better understanding of what is going on, think of the decathlon events. You can measure people’s performances in the running, jumping, and throwing categories, calculate correlation coefficients among them, do a factor analysis, and extract a general coefficient of athletic ability which would be analogous to Spearman’s g. Those who are generally good all-round athletes will have a high general coefficient and one can rank people according to this number. The degree to which a decathlete’s performance on any one event correlates with this general coefficient of athletic ability is analogous to this ‘g-loading’. If g-loadings are high, then that one event can be taken as a good proxy for the athlete’s overall decathlon skills.

Richwine’s dissertation depends a lot on a data set compiled by Richard Lynn and Tatu Vanhanen in two publications IQ and the Wealth of Nations (2002) and IQ and Global Inequality (2006) that compiled average IQ data across 192 nations. The results are given in Appendix A of Richwine’s dissertation (p. 135) and they range from a low of 59 for Equatorial Guinea to a high of 108 for Singapore and Hong Kong. You see a geographical pattern of IQ scores, starting with over 100 for East Asian countries that decline to the 90s as we go to south-east Asia, decreasing further to the 80s in Western Asia, North Africa, Pacific Islands, South-central Asia, and Central and South America, and sinking to the bottom of 70s and 60s in Sub-Saharan Africa. Meanwhile US and Europe (Richwine includes Canada, Australia and New Zealand in the European group) have averages close to 100. My native country Sri Lanka clocks in at a mere 79. (I have no idea what my personal IQ is since we never had to take these tests.)

So the IQ-based immigration policy advocated by Richwine would effectively end up being indistinguishable from a color-based Eurocentric policy

There is one immediate problem. Recall that these tests are normed to have an average of 100 (for America) and the standard deviation is 15. The idea that national IQ averages can range over more than three standard deviations boggles the mind. Why is this a problem? Because when you go more than one standard deviation below the norm, you are identified as having some level of cognitive impairment. The US Supreme Court has said that those with IQs below 70 (two standard deviations below the norm and who make up just 2.27% of the US population) have a prima facie case for being exempted from the death penalty because of mental incompetence. The idea that almost 85% of the entire population of Equatorial Guinea suffers from severe mental disabilities, and that their average IQ corresponds to the cut off for lowest 0.3% of the US population, is preposterous. The average IQ for American blacks is 85, which means that many of them can be classified as ‘dull normal’ and their average IQ corresponds to the cut off for the lowest 16% of white people.

There is another problem. Researcher James R. Flynn has found that IQ scores have been rising steadily at an incredible rate of about one standard deviation (15 points) over the last half-century, or about 0.3 points per year. This alone makes a mockery of the claim that IQ is rooted in biology and thus largely immutable, since it is inconceivable that such major changes in biology could occur over such a short time.

In his dissertation, Richwine acknowledges that these two issues are problematic for his thesis and that we have no satisfactory explanations for either (which is not quite true, but that is a topic for another day) but then proceeds to blithely ignore them. Furthermore Elspeth Reeve points out that Latinos in the US are assimilating over time, contrary to his claims that they are doomed to remain separate and an underclass, and Dan Drezner has looked at some of the other sources used by Richwine to support his case and says he is not impressed by their quality.

Next in the series: Some reasons why IQ scores are rising rapidly.

Comments

  1. Jeffrey Johnson says

    I can recall Jared Diamond in “Guns, Germs, and Steel” talking about the encyclopedic knowledge the average member of New Guinea tribes have about plants, animals, and the land. The idea that what humans learn and how they think would not be profoundly impacted by environment and culture is just crazy.

    If any American were taking IQ tests designed by Amazonians or New Gunieans, we would most likely have very low scores. They might pity us for being so stupid as to not understand what is basic to them. I merely assert this as my opinion and belief, but I think the adaptability of the brain and its learning ability pretty obviously argue against the notion that culture and environment (including socio-economic circumstances within a society) can’t have dramatic impacts.

  2. jpmeyer says

    “There is another problem. Researcher James R. Flynn has found that IQ scores have been rising steadily at an incredible rate of about one standard deviation (15 points) over the last half-century, or about 0.3 points per year. This alone makes a mockery of the claim that IQ is rooted in biology and thus largely immutable, since it is inconceivable that such major changes in biology could occur over such a short time.”

    My favorite example of this are the IQ tests from the early 1900s which showed newly-arriving Jewish immigrants to America having some of the worst IQ scores of any group at the time, which the race scientists of the time used as “proof” of their inherent inferiority to the Nordic Europeans. Of course, now current IQ testing shows them to have the highest IQ of all. Whoops!

    “I can recall Jared Diamond in “Guns, Germs, and Steel” talking about the encyclopedic knowledge the average member of New Guinea tribes have about plants, animals, and the land. The idea that what humans learn and how they think would not be profoundly impacted by environment and culture is just crazy.”

    I wish I could remember where I read this, but I remember reading that one of the reasons why people in places like Sub-Saharan Africa get horrible scores on IQ tests is because the test will have a question like “Which of these animals is not like the others: Cow, Chicken, Pig, and Dog”. The answer you’re supposed to give is “chicken” because it’s a bird and the other three are mammals, while they would answer “dog” because the other three are animals that they farm for meat.

  3. Mano Singham says

    Richwine argues that the IQ tests in the early 1900s that found that Jews had low IQs were biased and flawed and that in actual fact they had high IQs.

    I will be writing about the point you make in the last paragraph in the next post in this series because it is very relevant.

  4. hoary puccoon says

    The problems with the whole IQ-by-group issue are endless. To mention two more:

    — There are environmental effects-- notably prenatal nutrition-- that are known to affect IQ. In studies like that of Richwine, these effects are invariably confounded with genetic effects.

    — Even if a particular national group could be shown to have an actual, genetic average lower IQ, there is a wide spread of IQ scores within every ethnic group. There is no way to know from their ethnic group where any particular immigrant ranks relative to the receiving population. If a country wants to admit only smart immigrants, sorting on country-of-origin is a really, well, stupid way to do it.

  5. Mano Singham says

    Richwine advocates testing of individuals for IQ but admits that this is unlikely to happen just because of the sheer cost.

  6. says

    1. IQ doesn’t measure the ability or desire to work. So, to declare that anyone with an IQ below X is going to necessarily be a burden on society is completely and totally unsupported. That’s reaching a conclusion with zero facts to support it.

    2. Immigration policy critics want to have their “low IQ, therefore burden on society” cake and eat their “Mexicans are taking our jobs” cake too. Which is it? Are Mexicans taking our jobs (and therefore contributing taxes to pay for social services)? Or are they merely a tax sink because they’re too stupid to be productive members of society?

    In short, the entire argument is a red herring. And should inform immigration policy with precisely and exactly zero impact.

  7. Jeffrey Johnson says

    Those are two really great points. Let me add to #1 that high IQ is also no guarantee of being a credit to society. Many criminals are very bright, and being able to score well on IQ tests says nothing about a person’s organizational skills, self-discipline, or other practical sklls and abilities. Lot’s of really smart people never acheive much success or live up to their apparent potential.

  8. says

    Whenever there is an article critical of IQ as a representative metric, a certain Cleveland State University professor usually shows up as a stalwart defender of their utility. I wonder if he will make an appearance here now that Mano is writing about IQ.

  9. left0ver1under says

    The idea that almost 85% of the entire population of Equatorial Guinea suffers from severe mental disabilities, and that their average IQ corresponds to the cut off for lowest 0.3% of the US population, is preposterous.

    There is another problem. Researcher James R. Flynn has found that IQ scores have been rising steadily at an incredible rate of about one standard deviation (15 points) over the last half-century, or about 0.3 points per year. This alone makes a mockery of the claim that IQ is rooted in biology and thus largely immutable, since it is inconceivable that such major changes in biology could occur over such a short time.

    My take on this topic comes in two parts, neither of which swine like Richwine want to address:

    (1) What does -- and who is -- the “IQ” test for?

    These tests are, invariably, based upon educational systems of rich countries. (People used to say “western countries”, but that is geographically inaccurate and ignored the wealth of Asian countries) If I took an IQ test written by an Inuit or Samoan person, I’d probably get a low score because the test is based on what the writer is looking for, prefers, or is considered important in a specific culture or region.

    (2) What educational opportunities did the person have?

    The idea that all the people of a country are “mentally deficient” is ludicrous. I’d wager many of the hispanics derided by racists like Richwine are people who never had the chance to go to school, and their children may not be going either (e.g. travelling farm labourers).

    In many African countries, free public education does not exist. Parents must pay, and for many who can’t afford it, their children never go to school. They’re not mentally handicapped, they are handicapped by poverty and a lack of opportunity. If tests were done on second generation kids in families who emigrated from poor countries to rich ones, there would undoubtedly be high “IQ scores” among many because they put an emphasis on education and improving their lives.

  10. sailor1031 says

    It was my observation after thirty years spent in IT, that those with lower intelligence generally became managers. Those with higher IQs tended to become highly productive technologists or entrepreneurs, neither of which the managers could properly comprehend anyway! So I guess Richwine is correct -- those with lower IQs often became a drain on resources.

  11. Bryan says

    Taj, your link doesn’t work.

    Curious whether Dr. Singham has ever interacted with the CWRU prof who founded and edits the journal, Intelligence?

  12. Bryan says

    Doug Detterman / Psychology.

    We should meet for coffee, alcohol, or both. I’d get to interact with a theoretical physicist; you’d get the pleasure of meeting a hippie, liberal, pro-affirmative action, race realist.

    I agree the 3 standard deviation thing sounds absurd, but the data replicate when estimating IQs for the 50 U.S. states. The average Mississippian has a z score of -2.26.

    Do I think the average Mississippian is borderline mentally retarded?

    No.

    B

    p.s. The Flynn effect is not a g effect.

  13. lurker says

    I believe there’s no such thing as g. It’s an artificial construct. The original IQ tests were never meant to measure g, but to measure the level of accomplishments of school kids. In reality there are many different qualities that people can be ‘intelligent’ in that are not part of IQ tests and are most likely very different across culture. Still people will be differently abled at those things, but to measure it in IQ tests is ridiculous.

  14. says

    The Flynn effect isn’t pronounced on the subtests on which race differences are pronounced. The predictive value of a test, the heritability of that test, the degree to which it is affected by inbreeding depression, and the degree to which it is correlated to biological variables like brain size go together fairly well. In some cases, the correlations between these variables are monotonic. Race differences fall in this cluster: i.e., race differences are generally greater on more heritable, predictively better, and biological tests. This is good evidence that race differences are genetic. The Flynn effect, however, does NOT fall into this cluster.

  15. says

    You’re right, but keep in mind that menial jobs -- the kind that low-IQ, hardworking people often end up doing -- are becoming increasingly automated. That said, there are some menial jobs that only immigrants are willing to do, and that are not yet automated.

  16. Jeffrey Johnson says

    Maybe some really high IQ people can figure out a way that lower IQ people can be given compensating capital in the form of ownership of robots they can lease out for income as their jobs are replaced.

    Or is that too socialistic and offensive to the sensibilities of the privileged holders of capital, especially those who never had to do hard physical work in their lives?

    It seems in a just society, in a Rawlsian sense, it would simply be made part of the cost of automating.

    I remember once watching AJ Jacobs, who read the entire encyclopedia Britannica and wrote the book “The Know-It All”, on CSPAN book tv talking about his attendance at a Mensa meeting. It was pretty funny. My recollection is that he described a meeting of people who were pretty quirky, poor at socializing, obsessive and neurotic, and for the most part not very economically successful. That’s at least a data point that there is such thing as having too much IQ without the associated skills that actually make people successful.

  17. Jeffrey Johnson says

    I’ve noticed the same, in the software industry. It’s hard to overcome the gut feeling that the managers and owners are very parasitic on the real brains and producers of value. But then it’s easy to underestimate the difficulty of schmoozing customers and attending boondoggle golf weekends at fancy resorts and signing fat contracts for the commissions.

    Actually I had to attend an event like that once, and I actually hated it. I’m too introverted. So the smart people depend on the networking socializing glad-handers in some tangible way. But I think the engineers could get by without the sales and execs better than the other way around, especially if they were selling to other companies also run by engineers.

    Some how those with social skills but who can’t really build or make or design anything have inserted themselves between the cash flow and the real creators of value, and they skim of plenty of cash for themselves without adding much value to the whole operation. I often wonder how it is that the engineers aren’t the highest paid, and that they just outsource the money management, the finance, the legal contracts, and the accounting to mid-level MBAs and other managerial staff. The real visionary decision makers ought to be the engineers. That happened with some companies in the tech world, but there are many highly rewarded execs who seem like if they died tomorrow, the people who really know what is happening in the company would carry on quite well without them. Maybe this is just an illusion though. It’s hard to say.

  18. claw says

    I just wanted to say that I am studying some of your theories for an education class that I am taking. While I do value your opinion on IQ testing and agree with a lot of what you say, I have to say that I explored this site to find out more about what you think about IQ testing and was suddenly bombarded by the fact that you are an atheist. I have to say that fact alone made me sad. I encourage you to look into the apologetics series and really dig into these books. Prove to yourself whether the Bible or Science is true.

  19. Mano Singham says

    @claw,

    “Prove to yourself whether the Bible or Science is true.”

    Ask yourself this question: If you had to choose between giving up all the knowledge gained by science or all the knowledge gained from the Bible, which would you choose? For me the choice is easy.

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