IQ and the Wealth of Nations (Human Evolution, Behavior, and Intelligence) [Hardcover]

On balance, I think this book makes a valid point, and it deserves to be read. Collating the volume of IQ data that they did, and analysing it in an objective manner, was in itself a considerable achievement. Moreover, if one has any doubts about their methods and their data, the authors have provided an 18-page bibliography listing all their sources, which are largely from the peer-reviewed scientific literature. I have pursued some of these, and have found them to have been fairly represented in the book.

The reason why it evokes such strong emotions is because people would prefer to believe that such differences in mean IQs do not exist, and indeed, it would be a nicer world if they did not. But to deny the possibility that such cognitive differences might exist is like denying the existence of mosquitoes, simply because one does not like them. Viewed from the angle of evolutionary biology, and given that intelligence is the outstanding trait that has evolved in mankind and allowed them to dominate the planet, it would be more extraordinary if such differences in mean IQ did not exist. There have been several measured attempts to demolish arguments such as these, assigning all differences to environmental and cultural factors ('Guns, Germs & Steel' by Diamond, 1997, is a good example) none of which are entirely convincing. If you scratch away at many of these objections that purport to be objective, and you will often find a religious undercurrent, that such theories must be wrong because mankind is somehow special.

My major criticism is that the authors of this book talk about IQ when they should say average IQ, and in so doing, play down the spread of IQs. The measurement of IQ is such an uncertain art, and the natural spread observed lies in the region of 12-18 points SD, such that a difference of two or three points between two population means is likely to be meaningless. But this does not imply that a difference of 40 points, which is more than 2SDs, can similarly be dismissed! So yes, L&V might have overstated their case, but this does not mean that their case is not substantially valid, or at least, contains something that warrants further investigation.

A final word: before jumping to conclusions about this book, and the motivations of the authors, please read their conclusions on p.196.

Since about 25 years of IQ-research, this is the only book which is making a substantial difference. Around 1980 the last but one step forward had been made by Arthur Jensen, Hans Jürgen Eysenck, Helmar Frank, Siegfried Lehrl and myself in discovering the relationship between elementary cognitive tasks and IQ and hence working memory storage capacity. We had to wait long fo such a new breakthrough, and we are waiting still for even a far greater one, the discovery of the genes underlying psychometric intelligence.

Even I myself, active in this field for 40 years, till then did believe that the low mean IQ scores of some populations were mainly the result of inadequate sampling and environment. Since I read Lynn and Vanhanen, I am convinced that population differences are not mere artefacts.

In 2002, after the publication of "IQ and the Wealth of Nations" by Lynn and Vanhanen and the preliminary reports of PISA 2000, I became aware that PISA tests can be understood as IQ tests and that the transformation of PISA scores into IQ results yields very similar numbers. PISA scores, mean 500, standard deviation 100, can easily be transformed into IQ values, mean 100, standard deviation 15, by adding or subtracting the deviation from the mean in the relationship 100 : 15 = 6.67, that a mean of PISA 433 corresponds to IQ 90, PISA 567 to IQ 110, if PISA 500 is set to be IQ 100. Heiner Rindermann in his publications has confirmed that PISA transformed scores of nations are nearly identical with IQ means, published by Lynn and Vanhanen in this book.

The Pareto principle (also known as the 80-20 rule), the law of the vital few, states that, for many events, 80% of the effects come from 20% of the causes. The power of a nation does not depend of its mere number, but of the percentage of its cognitive elite, optimized by social evolution. Highly intelligent people are networking, and the economic effect of networking is the square of the nodes of the network, i.e. in our case the square of the number of people involved.

Lynn and Vanhanen show that non-market economies, in their increase in GDP, are not in step with market economies. While some former non-market countries with a high average IQ such as Estonia, the Czech Republic, Slovenia and especially China are narrowing the gap, those with a low average IQ seem to have no chance to catch up. On the one hand we have the impressive success story of Singapore, on the other hand are countries such as Haiti and Zimbabwe which are not only backward, but suffer from mismanagement and brain drain. In 1968, the Pacific island of Nauru possessed the highest GDP per capita in the world due to its rich phosphate deposits. Today, after the exhaustion of these deposits, Nauru -- faced with chaos amid political strife and the collapse of the economy caused by mismanagement and corruption -- has a GDP more in accordance with the mean IQ of its population.
One of the criteria which differentiate science from speculation is the power of prediction. In 2007, oil-producing Equatorial Guinea, a country with an average IQ of 59 (according to Lynn and Vanhanen), one of the lowest in the world, had a GDP per capita of 44,100$, one of the highest in the world. We can easily predict that, after the exhaustion of the oil, the GDP of this country will fall back into a range typical for a country with such a low average IQ. As long as the oil is flowing, a number of specialists and dealers of Lebanese, Chinese, Indian and other origins make money, but they will abandon such a country after the boom.

Even within developed nations the difference between prosperous and more backward regions amounts to 10 and more IQ points. For example, in Germany the IQ average of Bavaria is about 10 points higher than that of Bremen; in Italy the difference between Venice and Sicily is 13 points; in Spain the difference between Aragon and Andalusia 8 points; and in the United States the difference between New Hampshire and Mississipi is 10 points. Such differences, aggravated by internal migration between the economic core and the backward regions -- but not always of such magnitude -- will be found in any country. Within Brazil, the federal states of the south have an average IQ and GDP per capita similar to South Europe and four times higher than the states in the north-east of Brazil.
As we know, political turmoil and ethnic cleansing can eliminate or drive away the gifted of a country, and within a very short time harm the economy for decades to come . Highly-skilled citizens from stagnating economies are unlikely to merely watch their standard of living decline, and they will vote with their feet. Their migration amplifies economic divergence.
There are three types of men: Men (with IQ above 123), who invent machines, men (with IQ above 104), who repair machines, and men, who use machines. In a country where there are not enough men to construct and to repair a bridge, sooner or later traffic by railway will break down. This is the message of this extraordinary book.

This landmark book solves what is probably the most important question in economics, namely what factors determine the level and growth of national income per head. Previously it was believed that the main determinants were the quantity and quality of the capital stock. In Prof Lynn's excellent book he completely redefines our view on the determinants of national income and concludes that the main determinant is the quality of a nation's labour force, as proxied by its average IQ.

With hindsight this should not have come as a surprise given that about 70% of the national income is paid as remuneration to labour. It also should not surprise us that intelligent, motivated labour forces might be more likely to accumulate capital, develop new technologies and embody them in the capital stock.

Prof Lynn has collated the results of IQ tests in 81 countries and, by estimating the IQs of a further 104, has compared GDP per head to average IQs for a sample of 185 countries. He explains at the microeconomic level how IQ is a useful predictor of an individual's income. He then extends this to the macroeconomic level and shows that a nation's IQ is the most important determinant of its GDP per head.

Prof Lynn's work is also very useful in identifying other variables that determine national income, such as free market vs socialist economies. The nations that are significantly below the IQ regression line are the former socialist nations of Eastern Europe and China, whereas the nations above it are the European and North American market economies. Prof Lynn therefore convincingly explains all the nations that over or under-perform and, in so doing, provides an unintentional but powerful argument in favour of the market economy.

Prof Lynn's work is such a breakthrough that it clearly merits a Nobel Prize. Regrettably, given the current prejudiced political climate, this is unlikely to be forthcoming.