I hesitate to discuss a subject that brings out the bigots and, in its most extreme forms, some deeply ugly, ugly ideas.
Many people interested in economics and economic development will be familiar with this book:
Lynn, Richard and Tatu Vanhanen. 2002. IQ and the Wealth of Nations. Praeger, Westport, Conn. and London.
The conclusions of this book have always seemed bizarre and ridiculous to me.
If you can’t be bothered wading through the work, you can read a
summary of its content here and
here, or a good critical scholarly review like Richardson (2004).
The blogosphere has recently seen some revival of interest in this book, and, interestingly, of a welcome critical kind. Of all places, the
American Conservative has
an article questioning the central thesis (not a venue I’d expect to be critical!).
A former
World Bank economist Charles Kenny rightly attacks the book and those development economists parroting its thesis. Certain critics of Kenny seized on his use of Stephen Jay Gould’s
The Mismeasure of Man, pointing out
errors that Gould made. Frankly, I don’t think it is a big secret that good researchers opposed to racism found Gould’s book flawed (Flynn 1999: 373). Moreover, unfortunately for the critics of Kenny, the truth is that Lynn and Vanhanen’s thesis is undoubtedly balderdash.
For me the recent criticism is rather old news: for years, I have thought there was something deeply rotten in Lynn and Vanhanen’s
IQ and the Wealth of Nations. I’ll review the central thesis of the book and why it is false below.
I. What is Lynn and Vanhanen’s Thesis?
One finding of Lynn and Vanhanen that national differences in per capita GDP are correlated with differences in the average intelligence quotient (IQ) scores is both unsurprising and obviously true (Richardson 2004: 359). The further assertion that the difference in average national IQ is one major factor causing the national differences in GDP and economic growth might seem plausible, at a first glance, but even here doubts arise, if one assumes, as Lynn and Vanhanen do, that the direction from causality runs simply from IQ to GDP.
By the time we get to the book’s conclusion we find highly dubious, even repulsive, ideas indeed:
“The genetic factor in national IQs strengthens our thesis that national IQs are a causal factor responsible for the differences in economic development. The racial differences in intelligence that underlie the national differences in economic development and in the wealth and poverty of nations must have been present for thousands of years. .... If differences in national IQs are genetically determined to a significant extent, as we believe, we have to conclude that it would not be possible to eradicate these differences by any environmental interventions or manipulations except possibly by massive eugenics measures that would not be practical. For this reason, it will be impossible to achieve economic equality between nations. It is more probable that, with further technological developments demanding high intelligence, international economic inequalities will increase even more in the future. Perhaps ultimately, with continued immigration of third world peoples into economically developed nations, there may be such a large amount of biological mixing of racial groups that national differences in intelligence may be reduced and or may even lead to the disappearance of the present differences in national IQs, but such a process would take a long time. Thus, our conclusion is that we must accept that the world is divided into rich and poor countries and that the gap between them is partly based on genetic differences in intelligence, which will make it impossible to equalize economic conditions in different parts of the world.” (Lynn and Vanhanen 2002: 194).
These are words that you have to read again after a first reading, because you doubt if you read them right.
Strangely, after one reads this, on the very next page, one finds Lynn and Vanhanen asserting that “approximately 50 to 60 percent of the variation in per capita income and economic growth rates seems to be due to those other factors, which may include systematic, local and random factors” (Lynn and Vanhanen 2002: 195) – which seems to contradict their previous strident statement. Lynn and Vanhanen (2002: 195) find that the other factor driving economic growth is the extent to which a nation has a market economy, though I frankly doubt whether their simplistic notion of a “market economy” takes account of the extraordinary degree of intervention in, say, newly industrialised nations like South Korea, Japan, and Taiwan, where industrial policy, protectionism and partial government planning of economic development was the key to success.
Lynn and Vanhanen still conclude that “there will inevitably be a continuation of economic inequalities between nations. Intelligence differences between nations will be impossible to eradicate because they have a genetic basis and have evolved over the course of tens of thousands years” (Lynn and Vanhanen 2002: 195).
But, curiously, Lynn and Vanhanen do not draw radical libertarian conclusions from their thesis, but instead argue that the “rich countries may have to accept that they have an ethical obligation to provide financial assistance to the people of the poor countries for the indefinite future” and that “aid programs for the poor countries should be continued” (Lynn and Vanhanen 2002: 196).
Let us move to a critique of Lynn and Vanhanen.
II. Critiques
First, there is the issue of how reliable and representative Lynn and Vanhanen’s test data for many developing nations was: this has always been a legitimate charge levelled at them by critics. Of the 185 nations in their study, direct evidence for national IQ was available only for 81, while for 101 nations average IQ was merely estimated by data from other “most appropriate countries” (Richardson 2004: 359). And even some of the data here seems highly selective and unrepresentative: a survey of just 50 13–16 year olds in Columbia and 48 10–14 year olds in Equatorial Guinea (Richardson 2004: 359). Do samples of less than 50 children really give us reliable data on average IQ in these nations? I doubt it.
To my mind, one of most bizarre and questionable findings of the book was that Qatar (a country with a high GDP and per capita GDP) only had an average IQ of 78. On what was this based? According to Lynn and Vanhanen (2002: 217) it was based on nothing but one study of 273 12 year olds from 1987!
Even putting aside concerns about the reliability of average IQs as reported in the book, the second point fatal to the thesis is the so-called
Flynn effect (Richardson 2004: 359).
One can’t really discuss this subject without looking at the work of
James R. Flynn (Flynn 2009; Flynn 2008).
In essence, the Flynn effect is the rise in average intelligence quotient (IQ) scores, which are supposed to measure general intelligence (or
g), over the course of the twentieth century:
“the Flynn effect is the name given to a substantial and long-sustained increase in intelligence test scores measured in many parts of the world. When intelligence quotient (IQ) tests are initially standardized using a sample of test-takers, by convention the average of the test results is set to 100 and their standard deviation is set to 15 or 16 IQ points. When IQ tests are revised, they are again standardized using a new sample of test-takers, usually born more recently than the first. Again, the average result is set to 100. However, when the new test subjects take the older tests, in almost every case their average scores are significantly above 100.”
http://en.wikipedia.org/wiki/Flynn_effect
A consequence of the Flynn effect is that earlier generations would have done poorly on modern IQ tests: average modern IQ is higher than in the past.
If IQ tests really measure innate intelligence, as Lynn and Vanhanen maintain, then we should not see the Flynn effect. If IQ tests do not measure innate intelligence, then the whole study of Lynn and Vanhanen was a waste of time, for the IQ data they accumulate does not reflect the underlying and allegedly innate intelligence of the national populations in question (Richardson 2004: 359). Flynn himself now believes that the Flynn effect
is evidence of increased mental ability: if that is so, then the edifice of Lynn and Vanhanen – the supposed largely inflexible nature of IQ – falls like a house of cards.
The rise in average IQ in various countries over time has not been uniform, however.
Richardson has made a more significant criticism of Lynn and Vanhanen’s method:
“Their scheme is to take the British Ravens IQ in 1979 as 100, and simply add or subtract 2 or 3 to the scores from other countries for each decade that the relevant date of test departs from that year. The assumptions of size, linearity and universal applicability of this correction across all countries are, of course, hugely questionable if not breathtaking. Flynn’s original results were from only 14 (recently extended to twenty) industrialised nations, and even those gains varied substantially with test and country and were not linear. For example, recent studies report increases of eight points per decade among Danes; six points per decade in Spain; and 26 points over 14 years in Kenya (confirming the expectation that newly developing countries would show more rapid gains). (Richardson 2004: 359).
Different countries have seen different rates of increase in average IQ, and the most significant rises have been in developing or newly industrialising nations, such as, for example, Japan:
“Lynn and Hampson (1986) review five studies providing evidence on the secular trend of intelligence in Japan for the post World War II period. They conclude that two studies of the early post World War II period show substantial IQ gains of 9.9 and 11.4 IQ points per decade, giving an average of 10.7 IQ points per decade. Three studies of a longer period from approximately 1950–1975 – so for those approximately born 1940–1965 – show lower gains of 9.1, 8.3, and 5.7 IQ points per decade, giving an average gain of 7.7 IQ points per decade. This is the highest gain on a broad intelligence battery in the literature.” (Nijenhuis et al. 2012)
Japan, then, has seen an extraordinary rise in average IQ over this century. In the late 1800s or early 1900s, when Japan began to industrialise and experience industrial take off, it must have had an average IQ as low as any poor developing nation today, even if there was a mild to moderate Flynn effect from the 1860s–1920s. How, then, did Japan achieve such tremendous economic success? (my answer is: a major reason was successful
industrial policy). A low average IQ by modern standards did not prevent Japan’s industrialisation, nor should we expect such low IQs to stop economic development in the case of modern developing nations, given the right policies.
Similar things can be said about America: it is likely that the average IQ in America from 1910–1920 was about 76, and was perhaps even slightly lower in the 19th century: and without doubt lower than the average IQ today in Ghana, Congo, Uganda, and Tanzania: yet America still industrialised and developed rapidly. If an average IQ of 76 prevents industrialisation and economic growth, why did America develop?
It is obvious that economic development and GDP growth have complex and multiple causes.
As for IQ, it must be seen as a function of
both genetic and environmental factors. So what are the environmental factors that influence IQ? Most probably disease control, health care, nutrition, diet, culture and education. And these obviously have a very significant influence.
In the last few years, there has emerged strong evidence that simple interventions to reduce and prevent infectious disease in children will increase IQ considerably:
“Infectious disease is a factor that may rob large amounts of energy away from a developing brain. ... A great deal of research has shown that average IQ varies around the world, both across nations and within them. The cause of this variation has been of great interest to scientists for many years. .... Before our work, several scientists had offered explanations for the global pattern of IQ. Nigel Barber argued that variation in IQ is due primarily to differences in education. Donald Templer and Hiroko Arikawa argued that colder climates are difficult to live in, such that evolution favors higher IQ in those areas. Satoshi Kanazawa suggested that evolution favors higher IQ in areas that are farther from the evolutionary origin of humans: sub-Saharan Africa. .... We tested all these ideas. In our 2010 study, we not only found a very strong relationship between levels of infectious disease and IQ, but controlling for the effects of education, national wealth, temperature, and distance from sub-Saharan Africa, infectious disease emerged as the best predictor of the bunch. A recent study by Christopher Hassall and Thomas Sherratt repeated our analysis using more sophisticated statistical methods, and concluded that infectious disease may be the only really important predictor of average national IQ.”
Christopher Eppig, “Why Is Average IQ Higher in Some Places?,” Scientific American, September 6, 2011.
All of this totally undermines the idea of Lynn and Vanhanen that IQ differences between nations will be impossible to eradicate because of some kind of rigid and inflexible genetic cause of IQ.
III. Conclusions
The recent finding that the Flynn effect appears to have ended in some developed nations means that over time, with improved epidemiology, post and prenatal care, nutrition, education, welfare and economic development, national differences in average IQ scores will significantly diminish to insignificant levels.
One might conclude that the average national IQ is simply a measure of the size of a country’s educated middle class, and the size of that middle class is a consequence of industrial development (Richardson 2004: 359), and other factors.
Whatever the genetic component in human intelligence, it is clear that intelligence, if IQ tests really measure it, is also a function of environmental factors like epidemiology, health care (including pre-natal and natal and childhood health care), nutrition, diet, culture and education.
We can expect the IQ gap between the developing nations and the developed nations to close in the course of this century, as the Flynn effect most probably hits a wall in the developed world and the third world catches up. That will require a wide range of good policies to address all the factors that effect IQ.
Book Reviews of IQ and the Wealth of Nations
Godina, Elena. 2005. “IQ and the Wealth of Nations. By Richard Lynn & Tatu Vanhanen,”
Journal of Biosocial Science 37.6: 783–785.
Palairet, M. R. 2004. “IQ and the Wealth of Nations,”
Heredity 92.4: 361–362.
Richardson, K. 2004. “IQ and the Wealth of Nations,”
Heredity 92.4: 359–360.
Volken, Thomas. 2003. “IQ and the Wealth of Nations: A Critique of Richard Lynn and Tatu Vanhanen’s Recent Book,”
European Sociological Review 19.4: 411–412.
BIBLIOGRAPHY
Eppig, Christopher. 2011. “Why Is Average IQ Higher in Some Places?,” Scientific American, September 6.
http://www.scientificamerican.com/article.cfm?id=why-is-average-iq-higher-in-some-places
Flynn, James R. 1987. “Massive IQ Gains in 14 nations: What IQ Tests Really Measure,”
Psychological Bulletin 101: 171–191.
Flynn, James R. 1991.
Asian Americans: Achievement Beyond IQ. L. Erlbaum Associates, Hillsdale, N.J.
Flynn, James R. 1994. “IQ Gains Over Time,” in R. J. Sternberg (ed.),
Encyclopedia of Human intelligence. Macmillan, New York. 617–623.
Flynn, James R. 1999. “Evidence against Rushton: The Genetic Loading of the Wisc-R Subtests and the Causes of Between-Group IQ Differences,”
Personality and Individual Differences 26: 373–393.
Flynn, James. 2007. “Interview: James Flynn. Receiver of Wisdom,” The Guardian, 2 January 2007.
Flynn, James R. 2008.
Where Have all the Liberals Gone?: Race, Class, and Ideals in America. Cambridge University Press, Cambridge.
Flynn, James R. 2009.
What is Intelligence?: Beyond the Flynn Effect. Cambridge University Press, Cambridge, UK and New York.
Flynn, James R. 2010. “The Spectacles through Which I See the Race and IQ Debate,”
Intelligence 38.4: 363–366.
Godina, Elena. 2005. “IQ and the Wealth of Nations. By Richard Lynn & Tatu Vanhanen,”
Journal of Biosocial Science 37.6: 783–785.
Gould, Stephen Jay. 1996.
The Mismeasure of Man (rev. edn.). Norton, London and New York.
Hassall, Christopher and Thomas N. Sherratt, 2011. “Statistical Inference and Spatial Patterns in Correlates of IQ,”
Intelligence 39.5 (September–October): 303–310.
Kenny, Charles. 2012. “Dumb and Dumber: Are Development Experts Becoming Racists?,” April 30,
Foreign Policy
Lynn, Richard and Tatu Vanhanen. 2002.
IQ and the Wealth of Nations. Praeger, Westport, Conn. and London.
Nijenhuis, Jan te, Cho, Sun Hee, Murphy, Raegan and Kun Ho Lee. 2011. “The Flynn Effect in Korea: Large Gains,”
Personality and Individual Differences 53.2: 2012: 147–151.
Palairet, M. R. 2004. “IQ and the Wealth of Nations,”
Heredity 92.4: 361–362.
Richardson, K. 2004. “IQ and the Wealth of Nations,”
Heredity 92.4: 359–360.
Unz, Ron, 2012. “Race, IQ, and Wealth,” The American Conservative, July 18, 2012.
http://www.theamericanconservative.com/articles/race-iq-and-wealth/
Volken, Thomas. 2003. “IQ and the Wealth of Nations: A Critique of Richard Lynn and Tatu Vanhanen’s Recent Book,”
European Sociological Review 19.4: 411–412.