Posted on August 2, 2012

Replies to Ron Unz

American Renaissance, August 2, 2012

Editor’s Note: Ron Unz, publisher of The American Conservative, recently published a lengthy critique of Richard Lynn and Tatu Vanhanen’s IQ and the Wealth of Nations. Several critiques of Mr. Unz’s article have already been published, and may be found here, here, here, and here. What follow are replies by Richard Lynn and Helmuth Nyborg.

Richard Lynn’s Reply to Ron Unz

Ron Unz has made a number of criticisms of our work first published in IQ and the Wealth of Nations, in which Tatu Vanhanen and I presented IQs for all nations in the world. We showed that these are correlated at 0.50–0.75 with income as measured by GDP per capita, and we argued that national IQs are a significant determinant of economic development.

I reply here to Mr. Unz’s criticisms.

The Direction of Causation

Mr. Unz begins by raising the issue of causation in the association between national IQ and per capita income. He writes: “If high national IQ scores are correlated with economic success, perhaps the high IQs cause the success, but it seems just as possible that the success might be driving the high IQs, or that both might be due to some third factor.”

Mr. Unz attributes to us a position “which claims that the data demonstrate IQ is genetically fixed and determines which nations will be rich and which will be poor.” Later, he writes of “the IQ-makes-wealth hypothesis of Lynn and Vanhanen” as opposed to “the contrary wealth-makes-IQ hypothesis of traditional liberals.” He adds that we should take into account “the possible impact of malnutrition and other forms of extreme deprivation.”

My reply: Mr. Unz misunderstands our position. We do not propose that the IQs of individuals or of nations are genetically fixed. On the contrary, we are well aware that IQs have been increasing in many countries during the last 70 or so years and that these increases are a result of improvements in the environment, such as better nutrition and longer education. We propose a positive feedback relation from genetically based national IQs to per capita income, and from per capita income on national IQs.

We discuss the causal effect of per capita income on national IQs in IQ and the Wealth of Nations, in which we devote pages 185 to 189 to outlining how improvements in nutrition, health, and education would increase IQs in low IQ countries. We make the same point in our later book, IQ and Global Inequality (2006), in which we write, “While we believe it is impossible to avoid the conclusion that genetic factors are partly responsible for the race differences in intelligence that underlie national differences, we also believe that environmental factors also contribute to the national differences in intelligence. Widespread sub-optimal nutrition and poor health undoubtedly impair the intelligence of populations of the poor nations. . . . we do not doubt that improvements in nutrition would increase intelligence in economically developing countries” (p. 244). We repeat this point in our latest book, Intelligence: A Unifying Explanatory Construct for the Social Sciences (2012) in which we write, “differences in national IQs are based partly, although not entirely, on genetic differences between populations” (p. 354). Thus, we have consistently advanced a two-way causal model such that national IQs affect per capita income and per capita income affects national IQs.

Contrary to the position imputed to us that the IQs of nations are genetically fixed, more than 30 years ago I published data showing that the IQ in Japan has increased more rapidly than in the United States, and proposed that improvements in nutrition were one of the responsible factors (Lynn, 1977b, 1982). I have since published a number of other papers on the contribution of improvements in nutrition to secular increases of intelligence (Lynn, 1990, 1993, 1998, 2007, 2009).

IQ Differences in European Nations

Mr. Unz writes:

In order to minimize these extraneous factors, let us restrict our initial examination to the 60-odd IQ data points Lynn and Vanhanen obtained from European countries and their overseas offshoots over the last half-century. . . . What we immediately notice is a long list of enormous variations in the tested IQs of genetically indistinguishable European peoples across temporal, geographical, and political lines, variations so large as to raise severe doubts about the strongly genetic deterministic model of IQ favored by Lynn and Vanhanen. We also discover rather low IQ scores in all the reported samples of Greece’s impoverished Balkan neighbors in the Eastern Bloc taken before the collapse of Communism. Croatians scored 90 in 1952, two separate tests of Bulgarians in 1979–1982 put their IQs at 91–94, and Romanians scored 94 in 1972.

It seems more plausible that most of the large and consistent IQ gaps between Western Europeans and their Balkan cousins are less a cause than a consequence of differences in development and affluence during the era in which these IQs were tested.

My reply: Intelligence tests are imperfect measuring instruments, so we should not expect that different tests administered in the same country to different and imperfectly representative samples, to different age groups, and at different times, would give exactly the same results. Two different IQ tests given to an individual typically give different IQs, and are typically correlated at about 0.7. This is due to imperfect reliability, measurement errors, sampling differences, and because different tests measure different abilities such as verbal comprehension, non-verbal reasoning, spatial and drawing abilities, etc., and therefore give different IQs. In our list of more than 400 national IQs, there are inevitably some cases where some IQs for a country differ quite considerably, just as there will be other cases where there is very little difference. For instance, our four IQs for Canada range between 97 and 100, our four IQs for Indonesia range between 87 and 88, and our three IQs for Switzerland range between 101 and 104.

To overcome the problem of the variation of results in some countries, we have taken for each country the median of a number of IQs. This largely removes the problem of anomalous results.

Croatia and Austria

Mr. Unz notes that “the borders of Austria and Croatia are just a couple of dozen miles apart, both are Catholic countries that spent centuries as part of the Austro-Hungarian Empire, and it is quite difficult to distinguish Austrians from Croatians either by appearance or by genetic testing. Yet the gap between their reported IQ scores — 12 points — is nearly as wide as that separating American blacks and whites.”

My reply: It is a pity that here and throughout his critique Mr. Unz uses our limited ten-year-old national IQ data given in our first (2002) book and not our much more extensive recent data given in Meisenberg & Lynn (2011) and in our latest 2012 book which gives many more national IQs and therefore more accurate results. In our 2012 book we give three IQ studies for Croatia and estimate the IQ at 97.8 and two studies for Austria with a mean of 99.0. Thus, there is a slight drop of 1.2 IQ points from Austria to Croatia in the north part of the Balkans, as our theory predicts. If Mr. Unz had looked at our most recent data the problem he raises for Croatia and Austria would disappear, and the same is true of many of the other problems he raises.

Genetic Distinctions of European Peoples

Mr. Unz argues that “the European peoples are genetically indistinguishable,” and therefore that the IQ differences between them must be environmentally determined.

My reply: Mr. Unz is incorrect in his assertion that all the European peoples are genetically indistinguishable. In fact he contradicts himself on this point as he also writes that “although Greeks and Turks have a bitter history of ethnic and political conflict, modern studies have found them to be genetically almost indistinguishable.” Mr. Unz is correct that Greeks and Turks are genetically similar, as shown by by Cavalli-Sforza, Menozzi & Piazza (1996, p.268).

However, it is not correct to assert that “all the European peoples are genetically indistinguishable.” Classical anthropologists identified seven genetically distinguishable European races. These are the blue-eyed and fair-haired Nordics in northern Europe, the Alpines in central Europe, the East Baltics in Russia, the Mediterraneans — a darker skinned and brown eyed people in southern Europe — Celts in the west of Ireland and Brittany, Dinarics in the former Yugoslavia and south Poland, and Basques in southwest France. Genetic differences between European peoples confirming the classical taxonomy are given by Cavalli-Sforza, Menozzi & Piazza (1996, p.268). More extensive data for differences in the frequencies of 14 haplogroups in Europe and the Middle East and their association with IQs are given by Rindermann, Woodley & Stratford (2012).

Among the Mediterranean peoples, there is a genetic distinction between those in the southern Balkans, southern Italy and southern Spain, and those in the more northerly latitudes. It has been shown in numerous genetic studies that all the populations in the southern European latitudes are a genetic mix of European and Middle Eastern peoples. For example, the Taql, p1 2f2-8-kb allele has a frequency of between 28.3 and 43.7 percent in the Near East and North Africa, of 27.3 per cent in Greece, 20.8 per cent in Albania and 26.4 per cent in southern Italy, in all of which there was considerable immigration from the Near East and North Africa in pre-historic and historical times. The frequency of the allele drops to 14.1 percent in North Italy, 5.9 percent in the south of Spain and only 1.7 percent in the north. The allele has a low frequency in central Europe represented by France (3.8 percent) and the Netherlands (3.5 percent). There are similar population differences in the Y-chromosome haplogroup E (Hg E) in the Near East and North Africa, Italy, southern and northern Spain, and Central Europe, given in Lynn (2012b).

These genetic differences explain why IQs in the Balkans, southern Italy, and southern Spain are in the range of 89 to 95 and therefore intermediate between approximately 99 for central and north western Europe and approximately 84 for the Middle East (Lynn, 2010a; 2010b; 2012a; 2012b).

Immigrants in the United States

Mr. Unz states that immigrants from the Balkans into the United States are “considerably above most other American whites in both family income and educational level,” and he argues that this shows that the Balkan peoples have the same or higher IQs as central and north west Europeans:

If these differences of perhaps 10 or even 15 IQ points between impoverished Balkan Europeans and wealthy Western ones reflected deeply hereditary rather than transitory environmental influences, they surely would have maintained themselves when these groups immigrated to the United States. But there is no evidence of this. As it happens, Americans of Greek and South Slav origins are considerably above most other American whites in both family income and educational level. Since the overwhelming majority of the latter trace their ancestry to Britain and other high IQ countries of Western Europe, this would seem a strange result if the Balkan peoples truly did suffer from an innate ability deficit approaching a full standard deviation.

My reply: Mr. Unz exaggerates when he asserts that people in the Balkans differ by perhaps ten or even 15 IQ points from central and northern Europeans. The average IQ in the Balkans given in our 2012 book is 92, and therefore about 7 IQ points lower than that in central and northern Europe.

Mr. Unz also exaggerates when he asserts that immigrants of Greek and South Slav origins are considerably above most other American whites in family income. The average annual earnings ($US in thousands) of men aged 25-54 in the United States in 1979 were Austrians 29.4, Belgians 27.2, Danes 25.4. English 24.1, Finns 27.3, Germans 24.4, Greeks 25.7, Irish 24.5, Scottish 25.7, Scots-Irish 25.4, Yugoslavs 28.0 and Welsh 25.7. Thus, the income of Greeks and Yugoslavs in the United States is about the same as that of north and central Europeans, and not considerably higher as Mr. Unz asserts. These figures are given in the census of 1980 and are available in the Bureau of the Census Public Use Microdata sample.

That the incomes of Greeks and Yugoslavs in the United States should be about the same as those of northern and central Europeans is probably attributable to selective emigration from the Balkans. Typically, when people emigrate from poor regions to more affluent regions, migrants tend to have higher than average IQs. The reason for this is that a higher IQ is needed to envision the advantages and to plan and find the resources to migrate. This has been shown in the United States by Vigdor (2002), who has found that it was blacks with greater educational attainment (a proxy for intelligence) who migrated from the southern states to the northern states, with the result that blacks in the northern states have an IQ about ten points higher than those in the South. Kaufman & Doppelt (1976) report an average IQ of 90.5 for blacks in the northern states compared with approximately 85 for all American blacks, and around 80 for those in the southern states. Further evidence that migration is typically selective for intelligence is available for Scotland, from a follow-up study of 1,000 11-year-olds whose IQs were tested in 1947. By the age of 30, 17.2 percent had emigrated, and they had had an average IQ of 108.1 (Lynn, 1977b).

North and South Italy

Mr. Unz writes:

Similar sharp differences occur in the case of Italian populations separated historically and geographically. Today, Italian-Americans are very close to the national white average in income and education, and the limited data we have seem to put their IQ close to this average as well. This would appear consistent with the IQ figures reported for Italy by Lynn and Vanhanen, which are based on large samples and come in at just above 100. However, there is a notoriously wide economic gap between northern Italy and the south, including Sicily. The overwhelming majority of Italian-Americans trace their ancestry to the latter, quite impoverished regions, and in 2010 Lynn reported new research indicating that the present-day IQ of Italians living in those areas was as low as 89, a figure that places them almost a full standard deviation below either their Northern Italian compatriots or their separated American cousins.

My reply: The only region in Italy where the IQ is as low as 89 is Sicily. In the other four regions of southern Italy the IQ lies between 90 and 92. These IQs in the range of 89-92 cannot be described as “almost a full standard deviation below their Northern Italian compatriots.” A full standard deviation is 15 IQ points, but the difference between the north and the south of Italy is two thirds of a standard deviation. This difference can be explained by selective emigration of the more intelligent from southern Italy. As noted above, the IQ of blacks whose forebears migrated to the northern states of United States is ten points higher than that of those who remained in the southern states, and emigrants from Scotland had an IQ eight points higher than those who remained in Scotland. Emigrants from the south of Italy probably have similarly higher IQs.

Mr. Unz continues: “Although Lynn attributed this large deficit in Southern Italian IQ to substantial North African or Near Eastern genetic admixture, poverty and cultural deprivation seem more likely explanations.”

My reply: Mr. Unz needs to explain why there has been poverty and cultural deprivation throughout the far south of Europe. The consistently low IQs in southern mainland Italy (IQ: 91), Sicily (IQ:89), Sardinia (IQ: 90), southern Spain (IQ: 94.4), the Balkans (IQ: 92), Malta (IQ: 95.3), Cyprus (IQ: 91.8) and Turkey (IQ: 89.4), and the relatively high frequency of African and Middle Eastern genes in these locations make the genetic theory more plausible.

Israel and the Jews

Mr. Unz writes:

The Lynn/Vanhanen data on Jews also provide some suspicious IQ disparities. American Jews have among the highest tested IQs, with means being usually reported in the 110–115 range. Yet Lynn and Vanhanen report that Israeli Jews have strikingly low IQs by comparison. One large sample from 1989 put the figure at 90, while a far smaller sample from 1975 indicated an IQ of 97, with both results drawn from Israel’s large Jewish majority rather than its small Arab minority. The IQ gaps with American Jews are enormous, perhaps as large as 25 points, and difficult to explain by genetic factors, since a majority of Israel’s Jewish population in that period consisted of ethnic Askhenazi (European) Jews, just like those in America. The huge economic gulf between Israeli Jews, who then had less than half the average American per capita GDP, and American Jews, who were far above average in American income, would seem to be the most plausible explanation.

Sephardic immigrants to America, c. 1910.

My reply: Unz would have found the answers to the questions he raises if he had consulted my book The Chosen People: A Study of Jewish Intelligence and Achievements (2011). In it, I provide a considerable amount of information about the IQs of the Jews in different countries, and show that the average IQ of Askhenazi Jews in the United States based on 32 studies is 110, and the average IQ of Askhenazi Jews in Britain, Canada and Poland is also 110. My estimate of the IQ of European Jews in Israel is 106 and I discuss why this is lower than the IQ of 110 of European Jews in Britain, Canada, Poland and the United States. I propose that the explanation is that not all of those classified as European Jews in Israel are Ashkenazim. Of the 2.4 million people classified in Israel as European Jews, approximately 1.4 million (58 per cent) are Ashkenazim. About 900,000 are Russians, many of whom are not Jewish or in some cases are a half or a quarter Jewish, who claimed Jewish ethnicity in order to leave the Soviet Union. A further approximately 110,000 are Sephardim from the Balkans whose IQ is approximately 98. It is including these two groups that reduces the IQ of European Jews in Israel to 106.


Mr. Unz writes:

Perhaps the strongest evidence supporting this cultural rather than genetic hypothesis comes from the north western corner of Europe, namely Celtic Ireland. When the early waves of Catholic Irish immigrants reached America near the middle of the 19th century, they were widely seen as particularly ignorant and uncouth and aroused much hostility from commentators of the era, some of whom suggested that they might be innately deficient in both character and intelligence. But they advanced economically at a reasonable pace, and within less than a century had become wealthier and better educated than the average white American, including those of “Old Stock” ancestry.

My reply: Mr. Unz exaggerates. The average annual earnings ($US, thousands) of men aged 25-54 in the United States in 1979 have been given above and show that the average annual earnings of the Irish at 24.5 were about the same as others of “Old Stock” ancestry, e.g. English 24.1, Scottish 25.7, etc.

Mr. Unz writes:

The evidence today is that the tested IQ of the typical Irish-American — to the extent it can be distinguished — is somewhat above the national white American average of around 100 and also above that of most German-Americans, who arrived around the same time.

My reply: This is incorrect. The table below gives average IQs, calculated from g-factor scores, for seven ethnic groups in the United States. These data are from the NLSY79, for subjects aged 15-23 years, who were tested in 1980. The differences between the European groups are not statistically significant, and show that the typical Irish-American IQ is the same as the white American average.

Ethnic group IQ N
German 102.3 1701
Irish 101.5 578
English 99.7 2316
French 99.5 601
Italian 97.8 253
Hispanic 86.3 1506
Black 82.1 2934

Mr. Unz writes:

Meanwhile, Ireland itself remained largely rural and economically backward and during the 1970s and 1980s still possessed a real per capita GDP less than half that of the United States. Perhaps we should not be too surprised to discover that Lynn and Vanhanen list the Irish IQ at just 93 based on two samples taken during the 1970s, a figure far below that of their Irish-American cousins.

Even this rather low Irish IQ figure is quite misleading, since it was derived by averaging two separately reported Irish samples. The earlier of these, taken in 1972, involved nearly 3,500 Irish schoolchildren and is one of the largest European samples found anywhere in Lynn/Vanhanen, while the other, taken in 1979, involved just 75 Irish adults and is one of the smallest. The mean IQ of the large group was 87, while that of the tiny group was 98, and the Lynn/Vanhanen figure was obtained by combining these results through straight, unweighted averaging, which seems a doubtful approach. Indeed, a sample of 75 adults is so small it perhaps should simply be excluded on statistical grounds, given the high likelihood that it was drawn from a single location and is therefore unrepresentative of its nation as a whole.

So we are left with strong evidence that in the early 1970s, the Irish IQ averaged 87, the lowest figure anywhere in Europe and a full standard deviation below than that of Irish-Americans, a value which would seem to place a substantial fraction of Ireland’s population on the edge of clinical mental retardation.

My reply: Once again, it is a pity that Mr. Unz relies on our first study giving two IQs for Ireland rather than our latest compilation giving ten IQs for Ireland, from which we estimate an IQ of 95.

Mr. Unz writes:

Lynn’s views regarding the mostly genetic cause of low Irish IQ seem unwarranted. Ireland was then overwhelmingly rural and poor, with a low per capita GDP, while Irish Americans tended to be an urban population and a reasonably affluent one, and this sharp difference in external material conditions seems the most logical explanation for the wide disparity in IQ results. In further support of this environmental hypothesis, we should note that it has been estimated that nearly one-third of Australia’s population is wholly or substantially Irish in ancestry, with the balance mostly British, while the IQ results Lynn and Vanhanen report for Australia are all very close to the British average of 100.

Later in his article Mr. Unz considers the possibility of selective emigration from Ireland:

One might speculate that the smarter Irish immigrated to America, while their dimmer relatives remained at home, and the same was also true for the smarter Southern Italians, Greeks, or other Balkan Europeans. Similarly, perhaps the smarter European Jews crossed the oceans to New York Harbor in the years before World War I, while their dimmer relatives stayed behind and later moved to Israel after World War II. These explanations seem quite unlikely. The intra-ethnic IQ gaps being discussed are absolutely enormous — often approaching a full standard deviation or more — and that would imply a similarly enormous gap between the portions of the population that stayed and those that emigrated, with no contemporaneous source seeming to provide any indication of this.

My reply: Mr. Unz exaggerates. There are no cases in which “the intra-ethnic IQ gaps being discussed are absolutely enormous — often approaching a full standard deviation or more.” In our latest compilation we give the IQ for Ireland as 95, and therefore 4 IQ points — less than one third of a standard deviation — lower than that in northern and central western Europe. The IQ gap for southern Italy is ten IQ points, approximately two thirds of a standard deviation lower than that in northern and central western Europe.

Magnitude of Non-genetic Factors

Mr. Unz writes:

To a small extent, Lynn and Vanhanen acknowledge the possible importance of non-genetic factors, and they devote a few pages to a discussion of the impact of health, nutrition, and education on IQ scores. But they never provide any clear estimate for the magnitude of these influences.

My reply: In my book Race Differences in Intelligence (2006, p.70), I estimated that sub-Saharan Africans have a phenotypic IQ of 67 and a genotypic IQ of 80. Thus, I estimated that the adverse environment reduces their IQ by 13 IQ points and that genetic factors reduce their IQ by 20 IQ points, compared with Europeans. Thus, 43 percent of the low IQ in sub-Saharan Africa is attributable to adverse environments and the remaining 57 percent is attributable to genetic factors.


Mr. Unz writes:

Sharp critics of our heavy recent immigration from Mexico sometimes claim — or at least hint — that the intellectual weakness of these millions of newcomers may constitute a disastrous long-term burden to American society. On anonymous Internet forums such voices are often more explicit and directly cite Lynn and Vanhanen in placing the Mexican IQ at just 87, far below the white American average, and a worrisome indicator given that as much as one quarter of all Americans may be of Mexican ancestry by around the middle of this century. The IQ figure of 87 that they quote from Lynn/Vanhanen is correct, though admittedly based on a single 1961 study of Mexican schoolchildren in the most impoverished southern part of that country.

My reply: In our 2012 book we give two more IQs of 88 for Mexico. This is almost identical to the IQ of 89 of Hispanics in the United States given by Roth et al. (2001) in a meta-analysis of a number of studies.

Mr. Unz writes:

Ron Guhname . . . decided to explore the Wordsum-implied IQ of American-born Mexican-Americans and discovered a remarkable result. These IQs were quite low, 84–85, in the 1970s and 1980s, a result consistent with the IQ samples reported by Lynn/Vanhanen for that era. But the Mexican-American IQ then jumped 7 points by the 1990s and an additional 3 points by the 2000s, a rise of 10 full points in just 20 years, while the Wordsum-implied IQ values for white Americans rose merely 2 points during that same period, presumably as an aspect of the regular Flynn Effect.

In actual values, the Mexican-American Wordsum-IQ increased from 84.4 in the 1980s to 95.1 in the 2000s, while the rise for American whites was from 99.2 to 101.3. In addition, the late 1990s IQ of U.S.-born Mexican-Americans has been separately estimated at 92.4 from the large data set contained in the National Longitudinal Survey of Youth (NLSY-97), a figure consistent with these Wordsum-IQ findings. Thus, almost two-thirds of the IQ gap between American-born Mexican-Americans and whites disappeared in two decades, with these results being based on nationally-representative American samples of statistically significant size.

My reply: Contrary to these claims, there was no increase in the IQ of Hispanics relative to whites over the years 1986-2004 in a study by Ang, Rogers and Wanstrom (2010). However, I do not dispute that when people who do not speak English move from an impoverished country to the affluent United States, the IQs of their children increase a bit as a result of learning the English language and improved environmental conditions. Indeed I have documented an example of this in the early studies of Jews in the United States, when their IQs were about 100. It is only in the studies from the 1940s onwards that Jews obtain their average IQ of 110.

East Asians

Mr. Unz writes:

This strong relationship between wealth and nominal IQ seems to disappear when we examine East Asian populations. A few decades ago, China, Taiwan, Hong Kong, Singapore, South Korea, and even Japan had extremely low per capita GDPs relative to those of America or Europe, yet almost all their tested IQs were around 100 or higher, comparable to those of the wealthiest and most advanced European derived nations. In many cases, their incomes and standards of living were far below those of the impoverished nations of Southern and Eastern Europe, yet they showed no signs of the substantially depressed performance generally found in these latter countries, whose IQs were usually in the 88–94 range.

The most plausible inference from these decades of accumulated data is that the IQs of East Asian peoples tend to be more robust and insulated against the negative impact of cultural or economic deprivation than those of European groups or various others — a truly remarkable finding.

Mr. Unz concludes that the East Asians are an exception to his theory that depressed socio-economic conditions are responsible for the low IQs in southern Europe.

My reply: The East Asians are indeed an anomaly for Mr. Unz’s environmentalist theory. The IQ in impoverished China is the same as that in affluent Taiwan, Singapore, Japan, and South Korea. But Mr. Unz is wrong in his assertion that the high IQs of the East Asians despite depressed socio-economic conditions are an exception. The same problem for Mr. Unz’s environmentalist theory is present in the IQs of western and eastern Europe, where communism depressed socio-economic conditions but IQs have been virtually identical to those of affluent western Europe. In our 2012 compilation we give a median IQ of 97.2 for ten former communist countries and a median IQ of 99 for 14 countries of northern and central western Europe. This negligible difference of 1.8 IQ points indicates that the depressed socio-economic conditions of eastern Europe had virtually no adverse impact on their national IQs.

The comparison of the IQs in eastern Europe with those in northern and central western Europe provide a quasi experiment to test Mr. Unz’s environmentalist theory. Take a group of ten nations in eastern Europe, subject them to communism for half a century, with the result that their standard of living is greatly reduced compared with that in the control group of 14 affluent countries of northern and central western Europe. Mr. Unz’s environmentalist theory predicts that the IQs in the nations in eastern Europe will be greatly impaired, while our genetic theory predicts that the adverse environment will have had little adverse effect on their IQs. The fact that the impoverished environment of communism has had virtually no adverse effect on he IQs in eastern Europe confirms our theory of the largely genetic determination of national IQs and is a serious anomaly for Mr. Unz’s environmentalist theory.

The IQ of 97.2 in eastern Europe is significantly higher than that in the Balkan nations that have also experienced depressed socio-economic conditions comparable to those in eastern Europe, but where the median IQ is 92. The most reasonable explanation for this is that the people of the Balkans are a mixed race European-Middle Eastern people who differ genetically from those of eastern and western Europe.

The “Strong IQ Hypothesis”

Mr. Unz writes:

The central thesis of Lynn and Vanhanen’s work might be called the “Strong IQ Hypothesis,” namely that IQ accurately reflects intelligence, that IQ is overwhelmingly determined by genetics, and that IQ is subject to little or no significant cultural or economic influence after we adjust for the universal Flynn Effect.

My reply: This is not a fair summary of our position. We have never maintained that IQ is overwhelmingly determined by genetics, or that IQ is subject to little or no significant cultural or economic influence.

Mr. Unz’s alternative environmentalist theory of IQ differences between the European peoples fails. He starts with the assumption that there are no genetic differences between the European peoples, and therefore that the IQ differences between them must be environmental. There is overwhelming evidence that this assumption is incorrect. There are considerable genetic differences between the European peoples such that North African and Middle Eastern genes are more common throughout the south, and this explains why the IQs throughout the south are substantially lower at around 92 than those in central and northern Europe.


An unsatisfactory feature of Mr. Unz’s article is that although he disagrees with our position that there is a significant genetic determination of national IQs and that these have an effect on per capita income, he has nothing to say about the national IQ-per capita income relation as a world-wide phenomenon. He confines his discussion to IQ and per capita income differences in Europe, the IQ in Israel, and the IQs of Mexicans in the United States. These are minor parts of our work, in which we have shown an association between national IQs, race, and per capita income world wide and in Latin America, Africa, Asia, Australia and New Zealand. Perhaps Mr. Unz believes that in all these places environmental factors can explain the national and racial IQ differences, and that all races and nations have the same genetic IQ. Does he believe that sub-Saharan Africans (IQ: 67) and Australian Aborigines (IQ: 62) will achieve the same IQs and per capita incomes as Europeans in two or three generations? Readers of this exchange will no doubt look forward to seeing Mr. Unz’ answers to these questions.

Richard Lynn is Emeritus Professor of Psychology, University of Ulster, Northern Ireland. He is the author of many works on group differences in intelligence and their social significance.


Ang, S-W., Rogers, J.L. & Wanstrom, L. (2010). The Flynn effect within subgroups in the U.S.: Gender, race, income, education and urbanization differences in the NLSY data. Intelligence, 38, 367-384.

Cavalli-Sforza, L.L., Menozzi, P. & Piazza, A. (1996). The History and Geography of Human Genes. Abridged paperback edition. Princeton, NJ: Princeton University Press.

Kaufman, A.S. & Doppelt, J.E. (1976). Analysis of WISC-R standardization data in terms of the stratification variables. Child Development 47, 165-171.

Lynn, R. (1977a). The intelligence of the Japanese. Bulletin of the British Psychological Society, 30, 69-72.

Lynn, R. (1977b). Selective emigration and the decline of intelligence in Scotland. Social Biology, 24, 173-182.

Lynn, R. (1979). The social ecology of intelligence in the British Isles. British Journal of Social and Clinical Psychology,18,1-12.

Lynn, R (1982). IQ in Japanand the United States shows a growing disparity. Nature, 297, 222-223.

Lynn, R. (1990). The role of nutrition in secular increases of intelligence. Personality and Individual Differences, 11, 273–285.

Lynn, R. (1993) Nutrition and intelligence. In P.A. Vernon (ed.) Biological Approaches to the Study of Human Intelligence. Norwood, NJ: Ablex.

Lynn, R. (1998). In support of the nutrition theory. In U. Neisser (Ed) The Rising Curve: Long Term Gains in IQ and Related Matters. Washington, DC: American Psychological Association.

Lynn, R. (2006). Race Differences in Intelligence: An Evolutionary Analysis. Augusta, GA: Washington Summit Publishers.

Lynn, R. (2007). Nutrition and IQ. The Psychologist, 20, 471-2.

Lynn, R. (2008). The Global Bell Curve. Augusta, GA: Washington Summit Publishers.

Lynn, R. (2009). What has caused the Flynn effect? Secular increases in the Development Quotients of infants. Intelligence, 37, 16-24.

Lynn, R. (2010a). InItaly, north-south differences in IQ predict differences in income, education and infant mortality. Intelligence, 38, 93-100.

Lynn, R. (2010b). IQ differences between the north and south of Italy: A reply to Beraldo and Cornoldi, Belacchi, Giofre, Martini & Tressoldi. Intelligence, 38, 451-455.

Lynn, R. (2011). The Chosen People: A Study of Jewish Intelligence and Achievements. Augusta, GA: Washington Summit Publishers.

Lynn, R. (2012a). New data confirm that IQs in Italyare higher in the north: A reply to Felice & Giugliano (2011). Intelligence, 40, 255-259.

Lynn, R. (2012b). North-south differences in Spain in IQ, educational attainment, per capita income, literacy, life expectancy and employment. Mankind Quarterly, 52, 265-291.

Lynn, R. & Vanhanen, T. (2002). IQ and the Wealth of Nations. Augusta, GA: Washington Summit Publishers.

Lynn, R. & Vanhanen, T. (2006). IQ and Global Inequality. Augusta, GA: Washington Summit Publishers.

Lynn, R. & Vanhanen, T. (2012). Intelligence: A Unifying Explanatory Construct for the Social Sciences. London: Ulster Institute for Social Research.

Meisenberg, G. & Lynn, R. (2011). Intelligence: A measure of human capital in nations. Journal of Social, Political & Economic Studies, 36, 421-454.

Rindermann, H., Woodley, M. A. & Stratford, J. (2012). Haplogroups as evolutionary markers of cognitive ability. Intelligence, 40, 362-375.

Roth, P. L., Bevier, C. A., Bobko, P., Switzer, F. S., & Tyler, P. (2001). Ethnic group differences in cognitive ability in employment and educational settings: a meta-analysis. Personnel Psychology, 54, 297–330.

Unz, R. (2012) Race, IQ, and wealth. The American Conservative, August.

Vigdor, J. L. (2002). The pursuit of opportunity: explaining selective black migration. Journal of Urban Economics, 51, 391-417.


Helmuth Nyborg’s Reply to Ron Unz


Criticism is the essence of good science, but it must be fair to the data as well as to theory in order to be taken seriously. In both respects, I find Mr. Unz’s critique lacking. His selection from the literature is too narrow and his evaluation of the scientific consensus about Lynn and Vanhanen’s (L&V’s) many contributions is plain wrong.

With respect to data, Mr. Unz limited his review to old 2002 L&V data. Had he used later revisions of their data, some of his quarrels about intra-national inconsistencies in IQ would have withered.

Perhaps Mr. Unz’s view of the importance of environmental factors motivates him to take an overly hard look at some exceptions (actually quite real!) to the general rule of partial genetic influence, at the cost of missing the overall pattern in the mountain of data L&V provide. Mr. Unz therefore runs the risk of not seeing the wood for the trees.

Another suspicion is that his clear preference for environmental factors makes him almost blind to explanations emanating from the mass of behavior genetics data arising from carefully controlled, often large-scale studies of families, monozygotic and dizygotic twins reared together or apart and, not least, ordinary and trans-racial adoption studies — or combinations thereof. It is not fair to criticize L&V on the basis of an a priori exclusion of vast amounts of data. These data would, at least in part, contradict Mr. Unz’s ideas that environment is king, and that success and other environmental factors drive IQ, rather than intelligence being a combined function of genes and environment.

It is important to remember that the nature-nurture question has been taboo since the beginning of the 20th century, which means that progress in this area depends on avoiding unfounded attacks and disregarding relevant contrary results.

Mr. Unz claims, with no evidence, that the construction of western IQ tests or inconsistencies in their practical application make them unfair to non-whites. It would balance his evaluation of IQ data if he included the solid evidence against this cultural-bias view, as for example the data presented extensively in Arthur Jensen’s 1980 book, Bias in mental Testing. Most commentators on bias in IQ testing seem curiously unaware of the rich empirical literature on limitations in testing.

Regarding theory, Mr. Unz moves too fast in his critique of theory, and creates not a few straw men on the way. He claims, for example, that L&V hold a strong IQ hypothesis, saying in effect that IQ is 100 percent genetically fixed and immutable to environmental factors. This is simply untrue. Nowhere in L&V’s extensive writings will he find that they defend this imposter of a hypothesis, which obviously runs counter to all behavior genetics evidence. Without this straw man, much of Mr. Unz’s theoretical critique crumbles.

Finally, Mr. Unz sees it as a mystery why nobody before him simply looked carefully through L&V’s own evidence to find deficits in their work. This statement suggests that Mr. Unz is unaware of the many attacks on L&V over the years. Obscure academics claim to have found devastating flaws in their data — and are hailed enthusiastically.

It is a related mystery for Mr. Unz as to why the allegedly bad work of L&V could receive so much uncritical general applause as to establish them as undisputed and widely respected leaders of the field. The truth is that they represent a small isolated group of IQ researchers and behavior geneticists who are kept busy by repeatedly having to defend themselves against critiques that misrepresent their work, and against personal attacks from people who do not even find it necessary to read all the relevant basic literature first. This is not a mystery at all, but a natural part of the Greatest Collective Scientific Fraud of the 20th Century (e.g. Gottfredson, 1994, 2000; Nyborg, 2003; 2011). Mr. Unz does not improve this situation.

Helmuth Nyborg is a former Professor of Psychology, Aarhus University, Denmark.


Gottfredson, L. (1994). Egalitarian fiction and collective fraud. Society, 31 (3), Whole No. 209.

Gottfredson, L. (2000). “Equal potential: a collective fraud”. Society, 37, (5), vii/viii.

Nyborg, H. (2011). The greatest collective scientific fraud of the 20th Century: The demolition of differential psychology and eugenics. Mankind Quarterly, 51, 241-268. (see

Nyborg H. (2003). The sociology of psychometric and biobehavioral sciences: A case study of destructive social reductionism and collective fraud in 20th century academia. In Nyborg H. (Ed.), The scientific study of general intelligence: Tribute to Arthur R. Jensen (pp. 441-501). Amsterdam: Pergamon. (see


Update: Unz Replies to Lynn and Nyborg

Richard Lynn has now produced a lengthy and detailed rebuttal to my article Race, IQ & Wealth questioning his theories, as has Helmuth Nyborg, another leading IQ expert and strong supporter of Lynn. Their analyses have been published or highlighted on several prominent racialist websites, and I am herein providing my own rejoinder.

First, I will admit to being a bit confused about Lynn’s overall position. Although he often seems to be endorsing my viewpoint in its generality, he seems to strongly dispute nearly all the specific details.

For example, Lynn claims that he has never denied the substantial role of educational and other environmental factors in determining the IQ results of different populations, and that he is simply suggesting that genetic factors may also influence “some” of the IQ differences he reports. As it happens, this is almost exactly the central thesis of my own article, in which I argue that the evidence overwhelmingly refutes what I call the “Strong IQ Hypothesis,” but that a “Weak IQ Hypothesis” might very well be correct. Essentially, I am proposing that the enormously large differences in population IQ reported by Lynn are primarily due to factors of social environment—poverty, education, rural deprivation—but that even if these external differences were completely eliminated, there still might remain a much smaller residual genetic effect, though its size and direction is somewhat speculative.

But although Lynn seems to be affirming my “Weak IQ Hypothesis” in the general case, he seems to oppose it in every given particular, which I find perplexing. For example, the word “education” appears only once in the index of his 300 page book IQ and the Wealth of Nations, and in that reference he provides a few sentences citing academic articles claiming a strong educational role in IQ, but then follows with a paragraph debunking and refuting the notion that education has any fundamental or permanent impact on IQ. Meanwhile, there seems to be no discussion anywhere of related factors such as “culture” or “rural deprivation”, and I am not aware that he raises any of these possibilities in his reporting and analysis of specific national IQ scores, even when these seem to show massive fluctuations over time. He certainly does recognize the important role of various biological factors such as nutrition and health, but even these merit only three or four pages out of 300.

In his 2006 sequel, he discusses these issues at greater length, but with little more clarity or consistency. For example, he raises the possibility of socio-economic factors substantially impacting both IQ and educational attainment, but concludes “This explanation cannot be correct” based on adoption studies (p. 44). Although at points in the book he vaguely seems more open to the role of “social environment” as a factor, he almost never seems to consider it when he discusses specific differences in national IQs. I might speculate that he is providing himself some “plausible deniability” by accepting non-genetic explanations in the vague abstract while almost always ignoring or dismissing them in each specific case. If I am mistaken, and he does indeed support “the Weak IQ Hypothesis,” I would be very glad to know this.

Numerous others might also benefit from such clarification. Not a single one of the vast outpouring of critical remarks I have received from Lynn admirers has ever suggested that I was misrepresenting Lynn when I characterized his position as essentially IQ-determinism.

As to the specifics of Lynn’s rebuttal, one significant problem I quickly encountered was a high degree of what seems to be serious factual error. For example, he directly and repeatedly quotes me as claiming “the European peoples are genetically indistinguishable” and “all the European peoples are genetically indistinguishable,” devoting several long paragraphs to refuting this claim. However, I never made any such totally absurd and scientifically ridiculous statements, and when I asked him for his source, he was unable to locate it anywhere in my writings. Admittedly, I did claim that East Germans and West Germans were indeed “genetically indistinguishable” and also that Greeks and Turks are quite genetically similar (as Lynn himself has stated on various occasions), but obviously such statements are entirely different from claiming the same is also true for Swedes, Basques, and Greeks. As Lynn himself explains in rebutting my (non-existent) claim, Nordics tend to be fair and blue-eyed while Sicilians are very rarely so, rendering it rather unlikely those two groups would be “genetically indistinguishable.” If Lynn wishes to portray me as a total ignoramus on genetic matters that is certainly his privilege, but I would prefer he read my writing more carefully and avoid inventing spurious quotations to buttress his case.

In another example, Lynn implies my review of national IQs was careless in that I relied upon the data in his 2002 and 2006 books, and ignored the more recent and extensive data presented in his 2012 book. However, since this latter book was actually published on July 16, 2012, six days after my own article had been sent to the printers, I do not believe I can reasonably be faulted for failing to incorporate his new material. Furthermore, once I managed to obtain an electronic copy of his new 2012 book, I discovered it contained at least several puzzling anomalies, which Lynn has been unable to clarify for me.

For example, Lynn refutes my evidence for a low Ireland IQ during the 1970s by referring me to the more extensive data in his latest book, saying it debunks my claim. However, when I examined the Ireland IQs in that book (p. 402), I discovered that he had inexplicably failed to include the massive 1972 study of 3,466 students which established an Irish IQ of 87 and which had appeared in all of his previous books. When I asked him why he had excluded the largest early Irish IQ study, he said he had no answer, and that perhaps “this omission was a mistake.” As it happens, nearly all of his other Ireland data tends to be from around 1990 or later, and simply reinforces the strong evidence of a rapidly rising Irish IQ which I had already discussed in my own analysis.

As another example, I had pointed out that Austrians and Croatians were quite genetically similar, and that the huge 11-13 point IQ gap reported by Lynn (2002) seemed wildly implausible as a primarily genetic effect, probably instead reflecting the depressed socio-economic condition of Croatia at the time, and hence likely to rapidly shrink under economic development. Lynn “refutes” my claim by citing the more recent data in his 2012 book which shows the Austrian/Croatian IQ gap has now narrowed to just a single point, mostly due to a huge rise in Croatian IQ; this would seem the exact prediction of my own model. Strangely enough, his 2012 data allegedly includes a Croatian sample from the large Buj (1981) collection, which had never appeared along with the other 19 Buj results in any of his previous two books, and when I asked him why he had never previously included this particular Croatian result, he had no explanation.

Sometimes Lynn construes my slightly loose phrasing as serious error. For example, I mention that Lynn’s 2010 research showed that today the Southern Italian IQ “was as low as 89.” He claims I misquoted him, since only the Sicilian IQ was 89, while other parts of southern Italy were in the 90-92 range. Since his other studies had placed Northern Italian IQ at 102-103, I had described this gap of 10-14 points between Northern and Southern Italians as being “almost a full standard deviation” while he argues it is closer to being two-thirds of a standard deviation. Since the IQ gap between Southern Italians in Italy and those in America is so wide, he suggests that only the very smartest Southern Italians immigrated here, but this seems totally implausible, especially when we consider that mean reversion would have drastically reduced any initial difference. Furthermore, all the IQ data from the 1920s which I quoted placed Italian-American IQ back then in the 78-85 range, which directly contradicts Lynn’s hypothesis.

Lynn also challenges my Balkan analysis. His 2012 book places the Bulgarian IQ at 92.5 and the Romanian IQ at 91, with the largest and most recent Romanian study coming in at only 88. Just I claimed, these figures tend to be 10 points or more below such northern European peoples as the Germans, Dutch, or Swiss, and I find a strictly genetic explanation of this huge gap far less plausible than the obvious social differences between Europe’s wealthiest and its poorest countries. Lynn claims these very low Balkan IQs are due to substantial African and Middle Eastern ancestry, but I have never heard of this being the case for Balkan Slavs, and would like to see some evidence.

Lynn’s 2012 book also places the Greek IQ at 92, and he challenges my assertion that Americans of Greek or South Slav ancestry are actually well above the white American average in income, IQ, and other indicators of ability. However, I obtained this exact result from the GSS dataset by running RACE=WHITE/ETHNIC against the WORDSUM, EDUC, and CONINC variables. Both Greeks and Yugoslavs have Wordsum-IQ and years of education significantly above the white average, while the family income of both these ethnicities are among the highest of any white group, $122,700 for Greeks and $113,500 for Yugoslavs against just $97,900 for the average white American. These results would seem implausible if Lynn’s very low IQ figures for Greeks and Balkan Slavs were largely innate.

Again, Lynn suggests that only the absolutely smartest Greeks and South Slavs came to America, and again I point out there is no evidence for this, that the IQ differences results from such selective migration would have substantially regressed after the first generation, and that the 1920s American IQ tests for Greek immigrants placed them at just 83.

In attempting to rebut my GSS evidence of a very rapid rise in American-born Mexican-American Wordsum-IQ over the last few decades, Lynn cites a 2010 paper by Ang et. al which he says refutes my claim of such a Super-Flynn Effect. However, he is incorrect. The study he references aggregates all Hispanics, while my result was solely for American-born Mexican-Americans, a much smaller subset. Indeed, if the foreign-born Mex-Ams are included, the rise in Wordsum-IQ largely disappears.

Furthermore, I have also pointed out that between 1975 and 2011, there was a five-fold rise in the percentage of Hispanics taking the SAT, while the gap between white and Hispanic scores remained essentially unchanged. Given that the Hispanic results were dipping so much deeper in their ethnic ability-pool, I think this can only be explained by a large rise in general Hispanic academic performance.

Lynn also disputes my claim of an anomaly in the pattern of East Asian IQ scores. Yet across all of his 50-odd such IQ studies, there is just a single case of East Asians scoring below 100, despite enormous poverty and deprivation. Meanwhile, most of his Southern European IQ studies yield results closer to 90 than to 100. I am deeply skeptical that the East Asian/Southern European ability gap is actually so enormously large. Furthermore Lynn never addresses the historical fact that virtually all the Southern and Eastern European immigrant groups in America had tested IQs of around 80-85 during the 1920s, while their Chinese-American and Japanese-American immigrant counterparts usually scored 100 or above. I suspect huge factors of cultural, educational, and socio-economic deprivation were responsible for the absurdly low immigrant European IQ scores, and Lynn completely ignores this important evidence, perhaps because it would be very difficult to reconcile with his strongly genetic IQ model.

Finally, Lynn closes his rebuttal by repeating his boilerplate disclaimer that he has “never maintained that IQ is overwhelmingly determined by genetics,” although this seems to be his clear reasoning in every single particular example he discusses. However, if I am mistaken and he is not being disingenous on this point, I cannot possibly understand why he chooses to oppose the overall conclusions of my article. As mentioned above, I had emphasized that absolutely none of my analysis would rule out “the Weak IQ Hypothesis,” in which some residual European IQ differences might indeed be due to genetics rather than environment. If—as Lynn seems to be suggesting—this were actually his own position, why would he have written a heated 6,000 word rebuttal instead of simply thanking me for agreeing with him?


I find much less to discuss in Helmuth Nyborg’s rather brief rebuttal.

Nyborg criticizes me for relying solely on Lynn’s 2002 book, but as I have repeatedly made clear, I supplemented this with his 2006 book as well as some of his other books and writings. I obviously did not use the data in his 2012 book, since it appeared in print simultaneously with my own article. Nyborg also cites the contrary IQ evidence of twin/adoption studies, which I had already addressed at length in my own article.

He describes “the Strong IQ Hypothesis” as a “straw man” position, an “imposter” which “obviously runs counter to all behavior genetics evidence,” and I would certainly agree with those charges. But just because a hypothesis is patently absurd does not mean it may not be widely held or promoted in certain circles, and my entire article was merely intended to demonstrate that absurdity. Meanwhile, I pointed out that “the Weak IQ Hypothesis” seems perfectly consistent with all evidence, and if that is actually the position of Lynn and Nyborg, then we should have no major disagreement.

I am also very glad that Nyborg emphasizes that Lynn and his co-author stand as “undisputed and widely respected leaders of the field” of IQ studies. Some of my critics have grown very concerned over the major anomalies I have highlighted in Lynn’s data and and have begun suggesting that by focusing my attention on Lynn’s work, I was unfairly attempting to discredit the entire field of IQ research.

Finally, I do regret the nasty personal attacks and misrepresentations which Nyborg, Lynn, and many of their allies have endured. But given the many hundreds of caustic insults and harsh denunciations I have recently received from Lynn’s energetic admirers, I would suggest that there might be two sides to this story.

Update: Steve Pinker Responds to Ron Unz

Editor’s Note: Professor Richard Lynn has sent us a June 3 note from Professor Steven Pinker of Harvard to Ron Unz. Professor Pinker told Prof. Lynn that if he wished to circulate the note, it should include the following statement by Professor Pinker:

You’re welcome to circulate it on the condition that you add that I do NOT endorse your theory that cross-national differences in IQ have a genetic cause. It’s not that I would argue that these differences are necessarily 100% environmental, but I remain skeptical on this issue (while maintaining that the debate be fair, open, and accurate – hence my objections to Unz’s characterization).

Hi, Ron,

Interesting piece, and it’s important to engage with these issues. I think your argument has some (fixable) flaws, though. You characterize Lynn as claiming that 100% of the variance in intelligence (within and across groups) is genetic. For example you often describe his position as “determinism,” and the technical sense of a deterministic process is one with probability = 1. That allows you to cite evidence of changes of between-group rankings over time as a refutation of Lynn. But he didn’t make that claim, and so your argument doesn’t work–indeed, is just the kind of straw-manning that Gould was repeatedly guilty of. Say that he claims that half of the variation among groups is genetic (that’s not a bad ballpark for the variation among individuals within a group). Then all of your findings are completely compatible with Lynn–they would pertain to the 50 percent of the variance that is not genetic–and he would still be right that in a world in which all economic, political, and geographic differences were somehow annulled, there would still be substantial differences in the economic and technological fortunes of different countries. Which of course is still an incendiary statement in today’s intellectual climate.

Now, you could make your argument more respectable by reformulating it as follows. IF Lynn’s argument for genetic variance across countries is based SOLELY on the differences in mean tested IQ between countries (together with an extrapolation of the genetic contribution of within-group differences), you could use the existence of non-genetic variation over time to question that inference–viz., by showing that a genetic explanation of the difference in IQ scores is otiose; we already have an environmental cause that is sufficient to account for his data. But saying that historical variation makes the genetic contribution to the crossnational differneces otiose or unnecessary or unparsimonious is different from saying that it refutes such a hypothesis. It only refutes the hypothesis that genetic determination is perfect, which no one except for Gould’s straw enemies believes.

And of course it would have to be true that Lynn had no data supporting a genetic hypothesis (even a partial one) other than the national differences. I haven’t read his book so I don’t know whether that’s fair. In the case of racial differences within the United States, Jensen and Rushton do have additional data, such as that when socioeconomic status, income, education, and the like are all thrown into a regression, the black-white gap doesn’t go away; the fact that the children of black and white couples matched in IQ regress to different means; and others. This is not to endorse their arguments, just to say that if Lynn has similar ancillary data (other than the existence of variation) then your arguments are not enough to prove that the genetic contribution to group differences is 0; all you’ve shown is that it’s less than 100 percent, which Lynn has always acknowledged.

A few other points:

  • You may want to give Tom Sowell credit for making this argument first, in several books, including Race and Culture, and the second edition of Intellectuals and Society.
  • You write as if Lynn were a well-respected psychologist whose findings have been widely accepted. This is very far from the case. Outside the circle of a handful of bloggers and behavioral geneticists he is somewhere between obscure and radioactive. (I believe several of his books are either self-published or put out by fringe publishers.) This is not to say that such a reputation is deserved or not, but it would be a mistake to imply that you’re arguing against a widely accepted hypothesis — Lynn’s hypothesis is anathema to 99.99% of psychologists and, for that matter, academics.
  • You suggest that the evidence for a genetic contribution to variance within groups (as opposed to between groups) is based solely on a small sample of monozygotic twins reared apart. This is not true. It is based on a vast amount of data, including comparisons of identical and fraternal twins reared together, comparisons of biological versus adopted siblings, studies of full- versus half-siblings, studies of inbreeding depression, and other data. Many of these samples are enormous, coming from countries that administer IQ tests to every schoolchild and draftee and make the data available to researchers.

Despite these caveats in your argument, I don’t disagree with the conclusion. But I think you need to firm up the argument and attributions. Thanks for sharing it,