The book's content is irresistible - at its heart is a table of the average IQ scores of 81 different countries, drawn from studies published in peer-reviewed scientific journals. The national average IQs range from 107 for Hong Kong to 59 for Equatorial Guinea.
Lynn and Vanhanen benchmarked their IQ results so that Britain is 100. America scores 98 on this scale, and the world average is 90. IQ's are assumed to form a normal probability distribution ("bell curve") with the standard deviation set at 15. Here are a few examples:
Nation Avg. IQ
Eq. Guinea 59
Hong Kong 107
Admit it, you want to know what the rest of the table says! Beyond satisfying sheer curiosity, though, the strong correlation between IQ and the wealth of nations is of world-historical importance. From now on, no public intellectual can seriously claim to be attempting to understand how the world works unless he takes IQ into account.
How much can we trust these IQ results?
As soon as I received the book, I turned to Appendix 1, where Lynn and Vanhanen describe all 168 national IQ studies they've found - an average of just over two per country.
Are the results internally consistent? In other words, when there are multiple studies for a single country, do they tend to give roughly the same answer?
I expected a sizable amount of internal divergence. I spent 18 years in the marketing research industry, so I know how expensive it is to come up with a nationally representative sample. Further, Lynn and Vanhanen use results from quite different IQ tests. They rely most on the non-verbal Raven's Progressive Matrices, which were designed to be used across cultures, even by illiterates. Yet, they also have a lot of results from the Wechsler exams, which are more culture dependent - the Wechsler include a vocabulary subtest, for example. And they report results from other IQ tests, including a few from the oddball Goodenough-Harris Draw-A-Man test. Also, sample sizes vary dramatically, from a few dozen in some obscure countries to 64,000 for one American study. Finally, some studies were of children, others of adults.
This doesn't sound promising. Nevertheless, the results show a high degree of internal consistency. Here are the first eight countries for which they have multiple scores:
Argentina: 93 and 98
Australia: 97, 98, and 99
Austria: 101, 103
Belgium: 99, 103, 98
Brazil: 88, 84, 90, and 85
Bulgaria: 94, 91
China: 100, 92.5, 103.4
Democratic Republic of Congo: 73, 72
That's not bad at all. In fact, leaving aside China, the results are remarkably consistent. There are, of course, a few countries for which different studies came up with quite divergent results, especially Poland, where the two scores Lynn and Vanhanen found were 92 and 106. Still, the correlation among results when there are two or more studies for a country is a striking 0.94.
You shouldn't take every score on faith. The reported IQ for Israel (only 94????!!!) has elicited much criticism. Lynn has replied that he wanted to publish the data as he found it, even if some of it looked implausible. His hope is to encourage further research to resolve seeming anomalies.
The IQ structures of the two giga-countries, China and India, demand more intense study, in part because the future history of the world will hinge in no small part on their endowments of human capital. The demography of India is especially complex due to its caste system, which resembles Jim Crow on steroids and acid. By discouraging intermarriage, caste has subdivided the Indian people into an incredible number of micro-races. In India, according to the dean of population genetics, L.L. Cavalli-Sforza, "The total number of endogamous communities today is around 43,000..." We know that some of those communities - such as the Zoroastrian Parsees of Bombay - are exceptionally intelligent.
But we can't say with any confidence what is the long run IQ potential of Indians overall. Their current IQ score (81) is low, especially compared to China (100), the other country with hundreds of millions of poor peasants. Yet, keep in mind just how narrow life in rural India was for so long. In 1952, on the fifth anniversary of independence, the Indian government commissioned a survey to find out if the average Indian villager had heard yet that the British had gone. The study was quietly cancelled when early results showed that the average villager had never heard that the British had ever arrived!
It appears likely that some combination of malnutrition, disease, inbreeding, lack of education, lack of mental stimulation, lack of familiarity with abstract reasoning and so forth can keep people from reaching their genetic potential for IQ. Lynn himself did early studies demonstrating that malnutrition drives down IQ. The co-authors conclude their book by recommending that
"The rich countries' economic aid programs for the poor countries should be continued and some of these should be directed at attempting to increase the intelligence levels of the populations of the poorer countries by improvements in nutrition and the like."
A clear example of how a bad environment can hurt IQ can be seen in the IQ scores for sub-Saharan African countries. They average only around 70. In contrast, African-Americans average about 85. It appears unlikely that African-Americans' white admixture can account for most of this 15-point gap because they are only around 17%-18% white on average, according to the latest genetic research. (Thus African-Americans white genes probably couldn't account for more than 3 points of the gap between African-Americans and African-Africans.) This suggests that the harshness of life in Africa might be cutting ten points or more off African IQ scores.
Similarly, West Africans are significantly shorter in height than their distant cousins in America, most likely due to malnutrition and infections. The two African-born NBA superstars, Hakeem Olajuwon and Dikembe Mutombo, are both from the wa-benzi [people of the (Mercedes ) Benz]upper class. Only the elite in Africa gets enough food and health care to grow up to be NBA centers.
This also implies that African-Americans might be able to achieve higher IQs too, although the environmental gap between white Americans and black Americans appears to be much smaller than between black Americans and black Africans. As I pointed out in VDARE in 2000, the most promising avenue for improving African-Americans' IQs is by promoting breastfeeding among blacks mothers, who nurse their babies at much lower rates than whites.
In fact, we know that IQ is not completely fixed over time because raw test scores have been rising for decades, about 2 to 3 points per decade. To counteract this, the IQ test-making firms periodically make it harder - in absolute terms - to achieve a score of 100. Lynn was possibly the first scientist to make this phenomenon widely known, although New Zealand political scientist James Flynn has gotten more credit for this recently. And, indeed, Lynn and Vanhanen scrupulously adjust the test results in their book to account for when each test was taken.