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192 of 201 people found the following review helpful:
5.0 out of 5 stars
Winters Are Good For Your IQ Genes, March 23, 2006
The book's central finding: the world average IQ is no more than 90, and declines from north to south. An IQ of 90 is equivalent to the mental age of a White14-year-old. (Standardized IQ tests are normed to 100, the mental age of the average white 16-year-old.). Lynn also draws attention to the fact that a north-south IQ continuum has evolved, apparently through selection for survival in cold winters.
These findings in Lynn's latest book have profound geopolitical significance. They imply it may simply not be possible to transmit Western-style democratic and economic systems to the populations of Latin America and Moslem North Africa and the Middle East, let alone sub-Saharan Africa. They mean that the world's long-term problems will stem from its populations' capabilities-much deeper and more intractable than any "Clash of Civilizations"-style competition between different political concepts.
The implications for immigration are obvious: it can have fundamental, and permanent, consequences.
Lynn's book reviews more than 500 published IQ studies worldwide from the beginning of the twentieth century up to the present, devoting a chapter to each of the ten "genetic clusters", or population groups, as identified by Luigi Cavalli-Sforza and his colleagues in their mammoth 1994 book, The History and Geography of Human Genes.
Lynn regards these genetic clusters as "races". He concludes that the East Asians-Chinese, Japanese and Koreans-have the highest mean IQ at 105. Europeans follow with an IQ of 100. Some ways below these are the Inuit or Eskimos (IQ 91), South East Asians (IQ 87), Native American Indians (IQ 87), Pacific Islanders (IQ 85), South Asians and North Africans (IQ 84). Well below these come the sub-Saharan Africans (IQ 67) followed by the Australian Aborigines (IQ 62).
The lowest scoring are the Bushmen of the Kalahari Desert together with the Pygmies of the Congo rain forests (IQ 54).
After the ten chapters setting out the evidence for the average IQ of each of these ten races, there follows a chapter on the reliability and validity of the measures. These show that, although additional evidence may be required to confirm some of the racial IQ estimates, many have very high reliability in the sense that different studies give closely similar results. For instance, East Asians invariably obtain high IQs, not only in their own native homelands but also in Singapore, Malaysia, Hawaii, and North America.
To establish the validity of the racial IQs, Lynn shows that they correlate highly with performance in international studies of achievement in mathematics and science. And racial IQs also correlate with national economic development. This means they can help to explain why some countries are rich and others poor.
Lynn's last three chapters are concerned with the book's subtitle-An Evolutionary Analysis. They discuss how race differences in intelligence have evolved.
Lynn argues that as early humans migrated out of Africa they encountered the cognitively demanding problem of having to survive cold winters where there were no plant foods and they had to hunt, sometimes big game. They also had to solve the problem of keeping warm. This required greater intelligence than was needed in tropical and semi-tropical equatorial Africa where plant foods are plentiful throughout the year. Lynn shows that race differences in brain size and intelligence are both closely associated with low winter temperatures in the regions they inhabit. He gives a figure of 1,282 cc for the average brain size of sub-Saharan Africans, as compared with 1,367 cc for Europeans and 1,416 cc for East Asians.
Since I have argued many of the same positions as Lynn, I will add that Lynn's brain size data are backed by a great deal of independent, converging evidence, including that from brain weights at autopsy, endocranial volume, and external head size measures. (My book provides many details of individual studies.) Moreover, magnetic resonance imaging studies make clear that the relation between brain size and intelligence is highly reliable. Lynn is on very safe ground in his statements here.
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111 of 122 people found the following review helpful:
5.0 out of 5 stars
Case proved - time to move the research on, March 25, 2006
It would be difficult to fail to discriminate between Pygmies, Swedes, Japanese, American Indians and Australian Aborigines. Wearing evolutionary spectacles, the physical differences are clear racial adaptations to different environmental conditions, with climatic adaptations being particularly evident. Why would levels of intelligence not also have been differentially selected for between races?
Chapter 1 defines `intelligence' and motivates why IQ is a measure of it. Chapter 2 justifies the concept of `race' - depressing that this is thought to be necessary - and makes the argument of the first paragraph above.
Chapters 3 - 12 then itemise in great detail the results of numerous intelligence tests given to nine racially-distinguished populations: Europeans; Sub-Saharan Africans; Bushmen (South Africa) and Pygmies; South Asians (Middle-East, India, Pakistan) and North Africans; Australian Aborigines; Pacific Islanders; East Asians (China, Japan); Arctic People and Native Americans.
Base-lining Europeans at IQ = 100, Sub-Saharan Africans come out at around 67. Corrected for poor environmental conditions, Lynn estimates the genotypic IQ (the mean IQ Africans would have if raised in the same environment as Europeans) as around 80. Conversely, East Asians seem to have IQs centred around 105 (p. 130) while some populations of Ashkenazim Jews have mean IQs between 107-115 (p. 94).
Chapters 13-17 summarise racial differences, and propose an explanation based on the geographic radiation of homo sapiens out of Africa, the resulting geographical isolation of sub-populations, and the impact of two ice-ages (the first from 70,000 to 50,000 years ago, and then the more severe Wurm glaciation, 28,000 to 10,000 years ago). These culled the less-intelligent in those racial groups most exposed to arctic conditions as well as driving the more obvious physiological adaptations. The East Asians were particularly stressed by harsh conditions north of the Himalayas and east of the Gobi Desert.
I have some quibbles. Lynn's timeline of geographic dispersal makes no mention of the Toba event, 70-75,000 years ago, which was said to have created a genetic bottleneck. If today's races emerged from a radiation out of east Africa which post-dated that event, how would that affect the argument?
Secondly, the early evolution within east Africa (p. 225) is poorly argued. The contemporary IQ of 67 is not the one to use, as it factors in present-day malnutrition. In the `environment of evolutionary adaptedness', this would not have been the case, so why not use 80? Lynn then appears to suggest there is a `continual directional selection for intelligence' based on its utility, as if species always got smarter and smarter. However intelligence comes with large costs, in terms of the energy required for big brains, so one would expect instead an equilibrium where a species is no smarter than it has to be. So rather than a drift to smartness in Africa, isn't it more likely that we saw waves of replacement populations radiating from groups who got smarter in more isolated niches where they were stressed more?
This is not a coffee-table read. It is somewhere between a scientific book for the academic community and a popularisation. I think Lynn hopes to move the goal posts so that we can move onto some of the interesting consequential issues clearly identified in his research programme. If at times he seems to stray into IQ-reductionism, then this is probably symptomatic of the existing research community being currently below critical mass.
There may well be public policy implications of the research results aggregated, summarised and theorised in this book. But they are rightly not addressed here.
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41 of 44 people found the following review helpful:
5.0 out of 5 stars
Cornucopia of interesting facts, June 21, 2006
This superbly-researched and thought-provoking work is a must-read for anyone interested in trying to understand "big picture" human history, and to make sharp policy decisions that are based on facts as well as good intentions. The book is eminently readable, but contains so much information that sometimes it's easy to miss material. For example, the previous reviewer stated that Lynn "surprisingly forgets to connect his IQ data with historical facts such as: that the first great civilisations emerged in the Near East and Northern Africa not in Northern, Central or Eastern Europe..." Actually, this point is addressed on page 237, where Lynn discusses the retreat of the ice sheets, which still left heavily forested, cold regions in northern Europe, but milder areas in southern Europe that allowed for civilizations to gain a toehold.
This book is perhaps of ultimate importance in its discussions of the importance of micronutrients--a factor that is possible to improve. Highly recommended!
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