In their books “IQ and the Wealth of Nations” and “IQ and Global Inequality” the psychologists Richard Lynn and Tatu Vanhanen advance the theory that the economic state of a society is to a substantial degree reliant upon the IQ distribution within the population, with a tendency for higher IQ populations to produce stronger and more sophisticated economies than lower IQ populations. But there is not a simple relationship between IQ and economic development, for example, Asians probably (see section 2) have a higher average IQ than whites, yet it is whites who have produced the richest and most economically sophisticated societies to date. Moreover, there is no uniformity of economic development within races. Lynn and Vanhanen’s thesis is that IQ is a necessary but not sufficient condition for economic development. Put another way, societies with a high average IQ have the potential to progress to a sophisticated economic state but those with a low average IQ do not.
Such a conclusion is unsurprising because it mirrors what happens at the level of the individual – the lower the IQ of an individual the less likely the individual is to occupy a substantial and significant position in their society. This individual tendency is to varying degrees distorted by the amount of inherited material and social advantage an individual enjoys, but even within social groups with similar inherited advantage, the same tendency can be seen: the lower the IQ the less significant a position the individual is likely to occupy. In addition, there are absolute limits to what someone can do with a particular IQ, for example, someone with an IQ of 150 may or may not take a first in maths; someone with an IQ of 80 will never take a first in maths.
Lynn and Vanhanen’s correlations also suggest that the average IQ of a society will have a significant effect even if a society does not progress to the front rank of advanced states or peoples at any point in time. The Chinese and Japanese did not develop into modern industrialised states of their own volition, but even at the pre-industrial stage they had much more sophisticated economic systems than populations with lower average IQs, for example, compare China and Japan with sub-Saharan Africa at any point before China and Japan were forced into widespread trade with the West in the mid nineteenth century and began to industrialise.
If Lynn and Vanhanen are correct, they have achieved something much more profound than simply discover a relationship between economic development and IQ because the economic state of a society has fundamental implications for its social structure and social structure for the culture of the society. A more advanced economy necessarily requires a more sophisticated social organisation than a less advanced economy, because the social relationships needed to produce it are inherently more complex. An industrialised state requires large scale urban development to produce the concentrated population required to man factories. Urban development allows greater division of labour and increases the opportunity for a wider range of occupations, including greater scope for those which are not utilitarian such as the arts. Large conglomerations of people require extensive public administration and works.
What Lynn and Vanhanen are actually arguing for is a link between average national IQ and general social organisation: the higher the average IQ, the greater the opportunity for social complexity is the implication of their work. If this is true then the general nature of a society will be governed by the IQ distribution of its inhabitants. Societies will share certain fundamental structural similarities because IQ distribution sets limits to what a society may be, although that does not mean societies with a similar IQ distribution will match each other in the detail of their respective cultures. Take as an example two tribes of hunter-gatherers, one in South America and one in Africa: they will differ in their tribal rituals, the weapons they make, their marriage customs and the means by which they hunt and so forth, but they will share the same general social arrangements which allow them to survive: a high degree of group dependence, the general means by which they live (hunting and gathering), the division of labour between men and women, a nomadic life and so on.
The evidence on which Lynn and Vanhanen base their theory is substantial. In IQ and the Wealth of Nations they examined nearly two hundred IQ studies from around the world to obtain average national IQs for 81 countries. For those countries where the data is lacking Lynn and Vanhanen extrapolated their national average IQs from nearby countries with similar racial populations for which data does exist. For example, country A with no test data has two neighbours B and C with racially similar populations to country A. Countries B and C have test data which allows their national IQs to be measured at 85 and 87 respectively. The national IQ of country A is given as 86, the mean of B and C. Objections were made to this form of estimation by critics but Lynn and Vanhanen found a very high correlation of 0.91 between the 32 countries which were estimated in their first book from neighbouring country IQs but calculated from measured IQs in their second book.
In “IQ and Global Inequality”, Lynn and Vanhanen increased the number of countries for which they were able to calculate national IQs from test data from 81 to 113. The correlation between IQ and per capita income for 2002 (0.68) was similar to that in “IQ and the Wealth of Nations”.
For their second book Lynn and Vanhanen managed to calculate national IQs for all other countries without test data, thus obtaining national IQs for all 192 countries in the world. They found a correlation of 0.60 between IQ and per capita income for 2002 for the 192 countries. The correlation is close to that in their first book.
Lynn and Vanhanen have probably done as good a job as can be done with the available data in justifying their hypothesis by the correlation of data. However, it will not convince everyone, not even all of those who are not ideologically opposed to their ideas. Is there another method by which their hypothesis can be bolstered? There is – by taking the sociological/ anthropological/ historical and the commonsense route of appealing to what any individual can see for themselves in their everyday life. That is what I shall do over the coming months in a series of articles. These will be accessible as a group by clicking on the psychology category or the tag IQ.
Such an approach has the advantage of making the subject accessible to the general public, or at least to the intelligent and educated lay reader. This is a vitally important consideration, because the implications of research such as Lynn and Vanhanen’s are as political as it is possible for academic research to be. By definition it is a subject which affects everyone and consequently should be made accessible to as many people as possible.
I have a second end in view, namely, I want to explore the implications of Lynn and Vanhanen’s work if it does represent reality.