Possible Causes of IQ Differences among Countries
The influential book IQ and the Wealth of Nations has lots of interesting data. But it does not say much on reasons for the IQ differences it identifies. What is said is that IQ is primarily inherited from one's parents, and that what a child eats also plays a role. Van Sloan and Richard Lynn (bottom half) offer additional reasons here, based on natural selection principles of biology. Studies of identical twins show that for IQ, Nature (genetics) is more of a factor than Nurture.
1. Immigration seems to have a sorting effect on IQ. In the book IQ and the Wealth of Nations the national average IQ for China is 100. But IQ's for countries where large numbers of Chinese have migrated are noticeably larger (Hong Kong 107, Taiwan 104, Singapore 104). Perhaps individuals who migrate to (and remain in) a different country are smarter on average than their former neighbors who stayed at home.
2. Certain East Asian countries have the highest average IQ scores, particularly in mathematical/ spatial skills. This talent may develop because students in China, Korea, and Japan are required to recognize and utilize thousands of word characters. It's interesting that Japanese living in the US (who are taught in English ) score about 3 IQ.points less than their countrymen in Japan. This IQ difference is the opposite of the Chinese immigrants in point 1, who do learn to write in Chinese characters in Singapore. Click for outside research findings offering similar results. A complementary theory on high East Asian IQ's is the genetic effect of more centuries of emphasis on education, compared to Europe.
3. Many European countries have IQ's about as high as China and nearby Asian countries. Recent genetics studies have shown that both European and northern Asian peoples are descended from the same ancestors in central Asia. Perhaps the cold, harsh living conditions in central Asia (compared to milder climates for those migrating out of Africa into South Asia) created a selection process favoring those smart enough to survive in that harsh climate.
4. Jews in the US and Europe have some of the highest average IQ's in the world - around 112, some observers claim. With centuries of pogroms, ending in the World War II holocaust, Jewish populations in Europe have been repeatedly culled. It is not unreasonable to speculate that many smarter European Jews, including those families who had been successful in making money, were also more successful on average in escaping with their lives.
5. The average IQ in Israel of 94 may not be so surprising, on second look. In contrast to European Jews, the Jews of Middle Eastern and North African heritage test much lower on IQ. Israel combines both regional origin Jews in roughly equal numbers. It also has a large and rapidly growing number of Palestinian Arabs (compare the average IQ in Egypt of 83). Thus it many not be surprising for the mixed population in Israel to have an average IQ of 94.
6. In world averages, the US has the highest national income, but an IQ average of only 98. US IQ is below that of many other countries, including relatively poor China. Like Hong Kong, Taiwan, and Singapore, the US is largely a country of immigrants, and average IQ in the US may well be higher than in many of the countries from which the migrants came (as from Latin America). But along with a sorting of IQ levels, immigration may also favorably select those with greater ambitions. Research indicates that ambition may play an even greater role in individual financial success than IQ.
7. Current US border enforcement procedures may contribute to the economic strength of the US. On one hand, high IQ individuals outside the US are encouraged by employers here to get US work visas. On another track, the semi-porous border with Mexico tends to select for desirable workers. On average, the migrants with greater ambition and above average IQ are able to foil the US border protection systems. As in point 1 above, the average IQ of Mexican-Americans is greater than the average IQ in Mexico. The net result is that the pool of talented workers in the US grows, to the detriment of their native countries. One drawback might be the feisty youth gangs in Los Angeles and other barrios of illegals. But the overall benefits of an inflow of ambitious talent filtered illegally into the US likely far exceed such drawbacks.
8. In the past, the opposite of voluntary migration to another country was slavery. Nations like the US and Brazil were peopled with both types of migrants. Accordingly, opposite selection effects for the free and slave peoples were at work. On average, those arriving voluntarily (including indentured servants) likely had more ambition and brains than those who were caught and sent as slaves. The migrations into the US of both Eastern European Jews and Africans were the result of horrible events. Many people died in these events, especially in the originating countries. One process selected out people with higher IQ's and ambition, the other possibly the opposite. Thus we should not be surprised at the large difference in IQ's currently between these groups in the US. See: IQ and success for Blacks
Update/ Corroboration 10 April 2004: After writing the above, I discovered these relevant comments on http://www.rlynn.co.uk - Richard Lynn's website. The last paragraph is the same idea as Sloan's in item 3 above:
My major discovery is that the Oriental peoples of East Asia have higher average intelligence by about 5 IQs points than Europeans and peoples of European origin in the United States and elsewhere. I first published this finding in 1977 in a paper on the intelligence of the Japanese. In subsequent years the high Oriental IQ has been confirmed in numerous studies of Oriental peoples in Hong Kong, Taiwan, South Korea, China, Singapore and the United States.
The theory I have advanced to explain these race differences in IQ is that when early humans migrated from Africa into Eurasia they encountered the difficulty of survival during cold winters. This problem was especially severe during the ice ages. Plant foods were not available for much of the year and survival required the hunting and dismembering of large animals for food and the ability to make tools, weapons and clothing, to build shelters and make fires. These problems required higher intelligence and exerted selection pressure for enhanced intelligence, particularly on the Orientals.
Click for another scholarly writing by Lynn on analysis of racial IQ differencesViewer comment 11/3/04: "Thank you for creating the IQ section of your website. It's such a relief to find someone unafraid to post up the facts about the hereditary nature of IQ. It's unfortunate that the subject of a correlation between race and IQ is a taboo and "politically incorrect" subject in many academic circles, but you've managed to deal with it in a sensitive yet straightforward manner, and I applaud you for that."
- from a review of this book at http://www.amnation.com/vfr/archives/008902.html
From the work of Charles Murray and Richard Herrnstein, we know that IQ--the measurement of a person's ability to process information--is an important determinant of outcomes in the lives of individuals. From the work of Richard Lynn, we know that IQ is an important determinant of outcomes in the lives of societies, namely of national wealth. In Understanding Human History, Michael H. Hart applies these truths to human history and civilization as a whole. Starting with the exodus of homo sapiens out of Africa 60,000 years ago, he traces the role of intelligence as a leading factor in the rise and differentiation of civilizations.
As an intriguing example of Hart's speculative but fact-based approach, he takes the average IQ of modern day sub-Saharan Africans, which is 70, as an indication that the average IQ of all humans 60,000 years ago, when the exodus from Africa occurred, was 70. Then, based on the fact that the IQ of modern day Europeans and Asians is substantially higher than 70, he traces the upward graph of the IQ of the peoples of the respective geographical regions over the last 60,000 years. He explains the rise of IQ on the grounds of the theory advanced by Richard Lynn and Philippe Rushton--which makes a lot of logical and intuitive sense, though it's still a theory--that the cold winters in the northern hemisphere selected for higher intelligence. To apply the "cold weather produces higher IQ" theory to the entire history of mankind and to all human societies makes for a new and exciting approach to the human story, ranging from the branching out of Paleolithic hunter-gatherer tribes across Eurasia, to the reasons for the Neolithic Revolution (primarily that the IQ of certain groups had risen to the level required for the invention of agriculture, pottery, the domestication of animals, etc.), to the achievements of modern science (ditto), and everything in between.
While Hart is a self-described atheist and materialist, his approach is not reductive in that he does not claim that IQ is the only force driving the advance of civilizations. He considers a variety of factors. For example, he looks at the industrial revolution, which occurred first in Britain, and notes several factors that would be conducive to that event, including high IQ, and finds that Britain was the only country in which all of them were present. Or he looks at the epochal transition to modern times around the year 1500 (an event he says is equaled in importance only by the Neolithic Revolution), and asks why did it occur in Europe not China, notwithstanding the fact that the Chinese IQ is equal to or slightly higher than the European, and he notes several factors that helped push Europe past China despite its lack of IQ superiority over China. For one, Europe had a vast coastline with many peninsulas, so that the development of seamanship and exploration was a pressing need for the Europeans, while China was a vast self-sufficient inland country with a short coastline and no need for exploration. For another, China had ethnic homogeneity and a united government, and so did not have much need for innovation in weapons, while Europe with its many warring countries was in a "perpetual arms race" leading to the invention of improved firearms. Or he looks at the fact that agriculture was invented independently in three different parts of the world--the Near East, China, and Meso-America--and identifies the factors that made this possible, among which is IQ. Or he asks why agriculture was invented in the Near East (which he calls the Middle East, a term not normally used for the ancient world), by people with average IQ of 88, rather than by Indo-Europeans with average IQ of 100, and he says that the fertile soil and long growing season of the Near East was so favorable to crop growing that it enabled the people there to develop agriculture notwithstanding their lower IQs. He adds that if their IQ had been lower than 88, they could not have invented agriculture. Along the way, he punctures Jared Diamond's theory that geography and the availabiltiy of domesticable plants and animals were the determinative factors in the invention of agriculture and the beginning of civilization, and that intelligence had nothing to do with it. But as a further illustration of Hart's absence of dogmatism, even as he rejects Diamond's rejection of intelligence, he applies Diamond's theory where it applies. Thus he argues that the pre-Columbian peoples of Mexico and South America developed agriculture and civilization more slowly than Old-World peoples of similar intelligence because the Diamondesque factors of north-south orientation and relative lack domesticable plants and animals made those developments harder.
Here's another example of the way Hart combines the general intelligence factor with local and specific factors. Why did the ancient Greeks surpass all other peoples in cultural achievement? While the Greeks had the high Indo-European IQ, they were no more intelligent than other Indo-European peoples. The answer Hart gives is fascinating. The Greeks' proximity to the ancient, advanced civilizations of Egypt and the Near East made them the first Indo-European people to come into contact with those civilizations. This gave them a school to learn from--in the fields of architecture, the visual arts, the alphabet, and so on--and this, combined with their high intelligence, sparked their unique intellectual achievements. I'm reminded of Camille Paglia's important account of how the Egyptian "Apollonian" representation of the human form as beautiful and harmonious--godlike--inspired the beginnings of Greek art. Hart points out that in 600 B.C., when the Greeks had been in contact with Egypt and the Near East for centuries and had a fully functioning written language with an alphabet based on the Phoenician alphabet, the Indo-European Celtic, Teutonic and Slavic peoples living to the north of Greece, who had never come into contact with the Near East, were totally illiterate.
While Hart often treats intelligence as one factor among several in the rise of civilizations, in some cases he makes intelligence the sole explanation. A deeply interesting case in point is the Indo-European expansion. According to the most accepted view, the Indo-Europeans began as a single tribe living north of the Black and Caspian seas around 4,000 B.C. They then branched out geographically and linguistically, becoming distinctive peoples, which over the course of two millennia conquered all of Europe, as well as Northern India, Iran, and Turkey, then later Mesopotamia and North Africa. What enabled the Indo-Europeans to overcome every people they encountered?
After considering several explanations, Hart concludes:"The simplest explanation is that the original speakers of Proto-Indo-European possessed, on average, considerably higher intelligence than most of the peoples they defeated (including the Egyptians, Babylonian, Assyrians, Carthaginians, Phoenicians, Pelasgians, Tartessians, Iberians, Etruscans, Berbers, and Dravidian-speaking peoples), all of whom had evolved in milder climates than had the ancestors of the Indo-Europeans."
Go to: more on IQ's in Africa
Go to: Research data by race on IQ's and reaction time
Go to: Questions and Answers on race/ IQ issues