Race Differences in Intelligence

Richard Lynn, Race Differences in Intelligence: An Evolutionary Analysis, Washington Summit Publishers, 2006, 322 pp.

After Dysgenics, Eugenics, and IQ and the Wealth of Nations, what more does the prodigiously productive Richard Lynn have to say about race and IQ? A great deal, as it turns out, in what his publisher may be right in calling his magnum opus. In Race Differences in Intelligence, Prof. Lynn has assembled the most thorough collection of world-wide IQ data available anywhere, and supplemented it with well-argued theories about how racial differences evolved.

This is not a volume for conformists, in the sense that it does not spend much time beating down threadbare orthodoxies: that race does not exist, that IQ tests are biased, that environment and “racism” explain racial differences in achievement, etc. Prof. Lynn quickly summarizes the arguments in these areas, but writes mainly for an audience that already understands that race is real and that races differ in intelligence. His main interest is in assessing IQ differences, determining to what extent the differences are genetic, and sketching out the events of the past 100,000 years that probably caused these differences. It would be hard to imagine a clearer, more capable treatment.

‘Genetic Clusters’

Prof. Lynn divides homo sapiens into ten racial groups based on genetic similarities that follow traditional anthropological classification. He notes that before the vogue for pretending it does not exist — a vogue limited essentially to the United States — there were straightforward definitions of race. As a textbook from 1976 explains: “[R]aces could be called sub-species if we adopted for man a criterion from systematic zoology. The criterion is that two or more groups become sub-species when 75 percent or more of all individuals constituting the groups can be unequivocally classified as belonging to a particular group.” Prof. Lynn points out that one of the book’s authors, Luigi Cavalli-Sforza, now famously insists on writing about “genetic clusters” rather than races.

There are four recognized sub-species or races of chimpanzees, and two races of gorillas. There are as many as 79 different breeds of dog, and Prof. Lynn lists a few striking biological differences in human races. Almost all Amerindians, for example, have type O blood, and virtually no Australian aborigines have type B. Disease rates vary so much by race there is even a journal called Ethnicity and Health devoted to them. Europeans, for example, are 6.6 times more likely than East Asians to carry the gene for the disease phenylketonuria (PKU). Pygmies average about four feet seven inches in height. It is only with respect to their own species that some people refuse to see the obvious.

Much of Race Differences in Intelligence is devoted to descriptions of the sampling and methodology of the hundreds of intelligence studies Prof. Lynn synthesized in order to arrive at representative IQ figures for different races. He explains why he adjusted some results for outdated testing norms and others for skewed samples.

Summary of race differences in intelligence

Race	Location	N. Samples	N. Countries	IQ	Range
Bushmen	S.W. Africa	3	1	54	48-62
Aborigines	Australia	17	1	62	53-74
Aborigines	New Guinea	5	1	63	50-60
Sub-Saharan Africans	Africa	57	17	67	59-89
Sub-Saharan Africans	Caribbean	14	6	71	60-80
Sub-Saharan Africans	United States	29	1	85	77-93
Sub-Saharan Africans	Netherlands	7	1	85	83-88
Sub-Saharan Africans	Britain	18	1	86	73-94
S. Asians & N. Africans	South Asia	37	17	84	77-96
S. Asians & N. Africans	Britain	16	1	92	83-96
S. Asians & N. Africans	Europe	18	3	85	75-94
S. Asians & N. Africans	Africa	6	2	86	77-91
S. Asians & N. Africans	Fiji, etc.	3	3	85	82-89
Pacific Islanders	Pacific Islands	14	9	85	80-89
Pacific Islanders	New Zealand	12	1	90	81-96
Southeast Asians	S.E. Asia	11	6	87	85-93
Southeast Asians	United States	7	3	93	87-96
Native Americans	North America	19	2	86	69-94
Native Americans	Latin America	10	5	86	79-92
Arctic Peoples	North America	15	2	91	78-96
Europeans	Europe	71	25	99	87-105
Europeans	Outside Europe	23	12	99	93-103
Europeans	East Asia	60	7	105	100-120
Europeans	United States	26	1	101	96-109
Europeans	Elsewhere	9	5	102	95-110

For example, with regard to Europeans, he finds interesting deviations from the racial average of 100. Balkan peoples, for example, tend to have depressed IQs compared to other Europeans (Croatia 89, Serbia 92.5, Bulgaria 90), and Prof. Lynn attributes this to centuries of admixture with South Asians, mainly Turks, who ruled large parts of the Balkans. Greeks — who have an average IQ of 95 — are genetically closer to Iranians and other Southwest Asians than to Danes or Englishmen. Prof. Lynn also finds that Spain and particularly Portugal have scores lower than the European average. Portugal imported large numbers of Africans slaves from the 15th century onward, and the lower national average is probably due to interbreeding. Ireland (92) and Scotland (97) also have lower averages, which Prof. Lynn attributes to selective emigration: Men of better-than-average intelligence managed to leave during famines and other crises.

Most IQ studies of Africans have been of black Americans, and Prof. Lynn confirms the long-standing average of 85. He notes that this figure appears in the earliest IQ tests given at age three, and cannot be attributed to bad schools. Nor, he writes, is there any evidence of malnutrition among American blacks, so the differences from the white average are overwhelmingly likely to be genetic.

Recent studies in Africa itself give results that point to an average of 67, about the mental age of a European nine- or ten-year-old. Prof. Lynn argues that disease and malnutrition depress the African average by some 12 or 13 points, and that 80 is probably the figure the average African would achieve in a First-World environment. Prof. Lynn notes that in the United States, blacks benefit further from an admixture of white genes to the point that the average black has the equivalent of one white grandparent. He concludes from studies of mulattos that every percentage increase in white genes raises average black IQ by approximately 0.2 points, and that this accounts for the five-point advantage American blacks have over the 80-point genotypic intelligence of African blacks.

The Ethiopian “Jews” who emigrated to Israel reportedly have an average IQ of 65, but Prof. Lynn does not explain why the more advanced environment of Israel does not appear to have increased their intelligence. Madagascar has a notably high average IQ of 82, but the explanation is simple: It was settled by Southeast Asians before blacks reached it, and their large genetic contribution pulls up the average.

Africans have long had a reputation as lovers of rhythm. The 14th century Arab writer Ibn Butlan wrote that if an African “were to fall from heaven to earth he would beat time as he goes down.” Musical tests show that American blacks have about a ten point deficit compared to whites in pitch discrimination and memory for melodies, but have a slight advantage in understanding and reproducing rhythms.

One of the most obvious physiological correlates of the black/white intelligence difference is the disparity in brain size. Blacks have, on average, about 100 cc less brain tissue, and brain size has a well-established correlation with intelligence. Within families, the larger-brained children tend to be the smartest, and rats that learn mazes quickly have larger brains than those that learn slowly.

The well-documented cultural poverty of Africa before contact with whites or Arabs is almost certainly due to low average intelligence. No sub-Saharan people had the wheel, a written language, mechanical devices, multi-story buildings, or a calendar. Their words for counting consisted of one, two, few, and many, though some tribes could count to seven by combining twos and ones.

Bushmen and Pygmies appear to fall below even the low African average. Until about 1,500 years ago, Bushmen lived in many areas of southern Africa, and Pygmies covered large ranges in central Africa. Both groups were later pushed into undesirable areas by encroaching Bantus: the Bushmen into the Kalahari desert and the Pygmies into the Congo forests. Bushmen are physically unique, with yellowish skin and large buttocks. The men have penises that stick straight forward, and the women have inner labia that may hang several inches below their pudenda.

The average IQ of Bushmen has been tested at about 54, or the mental age of a European eight-year-old. This may seem a shockingly low average, but an eight-year-old can learn the simple hunting and gathering techniques practiced by Bushmen. Interestingly, Bushmen are better than Europeans at estimating the sizes of distant objects, an ability useful for hunting. This is a skill Europeans may have lost during the several thousand years they have lived as settled agriculturalists rather than as hunters.

Pygmies are normal in height until puberty, at which point they fail to grow quickly like people of other races. Prof. Lynn is aware of only one intelligence test of Pygmies, conducted in 1910. Unfortunately, the results were not quantified; the researcher noted only that Pygmies scored worse than Eskimos, Filipinos or Amerindians. Like the Bushmen, they have only primitive counting systems, and never succeeded in making the transition to settled agriculture.

The aborigines of Australia and New Guinea also have very low IQs. Those in Australia migrated about 60,000 years ago from New Guinea, and share many physical traits. The median IQ for both groups is 62.

At the same time, Australian aborigines score 119 — well above the white average of 100 — on a spatial memory test that requires them to study 20 objects for 30 seconds and memorize their locations. This ability is thought to have evolved in the Australian desert, where hunters must remember even the slightest geographic features, and aborigines have excellent reputations as guides and trackers. This ability is still found in aborigines who have lived in cities for several generations, which suggests it is a genetic trait. Aborigines have quite small brains, but with disproportionately large right hemispheres, which is the area that handles spatial memory.

Despite this unusual visual ability, the low intelligence of aborigines prevented significant cultural advance. Until contact with Europeans, they did not have agriculture, pottery or metal, did not store food, and kept no animals. The now-extinct Tasmanians are the only people known to have been unable to make fire. They could use it if they found it, but could not relight fires that burned out. Tasmanians had no tools with handles; their axes were unhafted rocks.

Europeans found the New Guinean aborigines to be at a slightly higher level. They grew yams and bananas, and kept chickens and pigs. However, these were practices they did not develop but learned from neighboring Southeast Asians and Pacific Islanders.

Professor Lynn groups the peoples of North Africa, the Middle East, India, and Pakistan into a single race he calls South Asians and North Africans. They have average IQs of around 84, with the exception of Turks, whose IQ of 90 can probably be attributed to hybridization with Europeans. Prof. Lynn reports that this disparate group has an average brain size about eight percent smaller than Europeans. Being reared in Europe increases their IQs somewhat but not to European levels. Gypsies are originally of Indian origin, and a group tested in Slovakia had a predictable average IQ of 84.

Prof. Lynn finds that Israelis have a weighted average IQ of about 95, with figures of 103 for Ashkenazim, 91 for Sephardim, and 86 for Arabs. Jews tended not to breed with the people among whom they lived, but were not completely endogamous. Prof. Lynn attributes intelligence difference between Ashkenazim and Sephardim to admixture from host populations. Ashkenazim in the United States and Britain tend to score in the 107 to 115 range, considerably higher than Israeli Jews. Prof. Lynn suggests that this is because only the more intelligent were able to come west to escape persecution in Russia and Eastern Europe. Emigration has been easier since the creation of Israel, which has been the more recent destination for Ashkenazim.

Prof. Lynn uses the name of Southeast Asians for the people called Malays in classical anthropology: the populations of Burma, Thailand, Indonesia, Philippines, Malaysia, etc. They have smaller brains than Europeans and have an average IQ of around 87. In the United States, this group scores at about 93, no doubt because of improved environment.

The Pacific Islanders are a heterogeneous group with an average IQ of 85. The exception are the Maoris of New Zealand, whose average of 90 is attributable to miscegenation with Europeans. Native Hawaiians in Hawaii share the racial average of 85.

Aside from certain groups of Ashkenazim, the East Asian populations of China, Japan, and Korea have the highest average IQs in the world. Numerous studies suggest an average of 105, with a consistent superiority of spatial intelligence over verbal intelligence. This group also has slightly larger brains than Europeans, and the loss of brain tissue that accompanies aging sets in later in Asians. Studies of Asians adopted by Europeans have found that the children have higher average IQs than the white populations. Interestingly, Prof. Lynn finds that Asians who immigrated to the United States or Canada several generations ago have lower IQs than those who have arrived recently or who stayed in Asia. He attributes this to the fact that early immigrants came to work on farms and railroads and were probably below-average in intelligence.

American Indians are genetically related to East Asians but with a considerably lower average IQ of 86. Like East Asians, they have a relative advantage in spatial IQ (89.5) over verbal IQ (81). On music tests, they outscore whites on rhythm (104), and do reasonably well on pitch and tune memory (92). Like Australian aborigines, they have good visual memory. Prof. Lynn suspects this may explain why they are often good spellers; they are able to remember the way words look.

In Central and South America, malnutrition lowers the Indian IQ. Iodine deficiency, for example, causes cretinism that can reduce IQs by as much as 13.5 points. Prof. Lynn reports that in the rural highlands of Ecuador, seven percent of the population are cretins and another 21 percent may have sub-clinical cases of cretinism that depress intelligence.

Arctic people have an average IQ of 91 and show the East Asian profile of better spatial than verbal intelligence. In a test in which they are shown a picture and asked to draw it from memory, they outscore Europeans 106 to 100. Good visual memory is an advantage in navigating featureless terrain and, like Indians, seems to make Eskimos good spellers.

The Evolution of Differences

Some of Prof. Lynn’s most interesting observations are his summaries of the millennial forces that produced race differences in intelligence. Prof. Lynn accepts the view that homo sapiens appeared about 200,000 years ago in Africa and left the continent to colonize the globe about 100,000 years later. He notes that one of the important boosts to pre-human intelligence came from the fact that we are social creatures. Monkeys, for example, make alliances and jockey for supremacy, and this requires intelligence. It takes brains as well as brawn for a monkey to reach the top, where he is in a position to mate with many females.

Climate change in Africa that turned forests into savannahs was another factor in raising pre-human intelligence. Grasslands offered much less cover than forests, and proto-homo had to learn how to fight off predators. He also learned to walk upright so as to get a better view, and thus freed his hands for tool-making. About 100,000 years ago man moved out of Africa, but it took him about 70,000 years to colonize the planet. Prof. Lynn argues that it was the demands of colder, non-African environments that forced the pace of evolution in intelligence and gave rise to race differences.

It is clearly much harder to live through sub-arctic winters than near the equator, where temperature hardly varies. Humans had to learn to use needles and thread to make clothes and tents, to keep babies and children warm, and to control fire. Unlike Africans, who could gather food year-round, bands that went north had to have the foresight to store food for the winter. Likewise, meat became a much more important source of food because plants were not available in the winter, and men had to learn how to track and kill large animals. This required cooperation, intelligent speech, tools for killing and butchering, and arithmetic for sharing carcasses. Even in modern times, hunter-gatherers in northern climates depend much more on meat than tropics-dwellers, and need more tools. Early humans dried and stored meat for the winter, but if they did it wrong the meat went bad and they caught food poisoning. This, too, helped winnow out the unintelligent.

Cold weather forced women to be selective about mates. Unlike African women, who could forage for themselves and their children all year, northern women were completely dependent on men. They needed mates who hunted well and had the foresight to store food, so could not settle for dummies. Men had to choose women who could be counted on to keep fires going and children fed and warm. At the same time, prolonged dependence forced northerners to develop durable family ties. Parents who did not stick together through winter after winter were unlikely to have children who survived. In the tropics, a woman could feed a brood without a man’s help.

The consequence, writes Prof. Lynn, is that there is a strong correlation of 0.68 between racial IQ and cold-winter environments. There is an even stronger correlation of 0.92 between IQ and lightness of skin color, which developed in northern latitudes.

Prof. Lynn notes that there have been two major coolings of the earth that pushed humans towards higher intelligence: the first ice age of 70,000 years ago, and the second ice age, or Würm glaciation, of 28,000 to 10,000 years ago. Africans who never left the continent did not experience either ice age, and their IQs did not rise. Likewise, the ancestors of the Australian and New Guinean aborigines left the continent after the first ice age but arrived in their new tropical homes before the second. They, too, failed to benefit from the rigors of cold weather.

Both East Asians and Europeans endured both ice ages, and Prof. Lynn argues that Asians evolved an IQ advantage because winters in Asia were colder. Asia is a larger landmass, and is not warmed by ocean currents. Particularly harsh winters pushed East Asians towards the Arctic body-type of thick trunk, short arms and legs, and a subcutaneous layer of fat that produces a yellowish skin color. Their flat faces keep extremities from freezing, and the epicanthic fold cuts glare from snow and ice. Asians also have little facial hair, an advantage in cold weather when condensation can freeze on beards and lead to frostbite.

Temperature alone, however, does not explain all race differences. Why, for example, do the Eskimos not have the highest IQs? They have even thicker trunks and shorter arms and legs than Asians, which shows they have endured harsher cold than Asians. Prof. Lynn explains that their environment did push their average IQ into the low 90s, but thoerizes that the intelligence breakthroughs found in other races probably required mutations that simply did not take place in small, Arctic bands. Fortunate mutations are much more likely in large populations.

This may also help explain why North American Indians did not develop higher IQs. Prof. Lynn rejects the theory that the Americas were populated only during the last 14,000 years or so, citing evidence that pushes the arrival of humans back to 40,000 BC. They did come from Asia, however, which explains their spatially-skewed IQ profile, Asiatic appearance, and lack of facial hair. However, most of them went south before the Würm glaciation, and avoided the need to adapt to the cold. They are therefore not as short-legged or flat-faced as East Asians, and tend to resemble the Ainu. In Japan, where they were the original inhabitants, the Ainu did not have to adapt to the intense cold of the Asian mainland, and did not develop completely Asian features or the Asian IQ.

Once they arrived in North America, Ainu-like Asiatics found life easer than in the East. America was filled with large game animals that were easy to kill. Herbivores and carnivores usually evolve higher intelligence because of each other, with predators getting smarter to catch their prey, and herbivores getting smarter to escape. Prof. Lynn argues that North American game animals had evolved with few natural predators, and were no match for recently-arrived humans. Even so, the Indians who stayed in the north had to survive the Würm glaciation, and should have been pushed towards higher IQ. Prof. Lynn speculates that like Arctic peoples, their numbers may have been too small to give rise to fortunate mutations.

Likewise, climate does not explain why civilization appeared first among the relatively low-IQ race of South Asians and North Africans rather than Europeans. Prof. Lynn suggests it was because Europe was covered with dense forest, did not have fertile alluvial plains like Egypt or Mesopotamia, and had tough soil not easily plowed like the soil to the south and east. For whatever reason, Europe produced real civilization in Crete and Greece only around 2500 BC, well after the North Africans and South Asians.

China, too, was well ahead of the West until the Renaissance. Why did it not keep its lead? Prof. Lynn speculates that Asians may be more conformist than Europeans, and therefore less likely to strike out in new directions. He also argues that since China was ruled centrally for millennia, it may have encouraged more uniformity of thought than the competing kingdoms of Europe. Whatever the explanation, there are signs European people are losing their confidence and could slip behind again.

As Prof. Lynn has already shown in IQ and the Wealth of Nations, the intelligence of a people is highly correlated with its economic success. In fact, there is much about the world that hardly makes sense without an understanding of racial differences in intelligence. Egalitarians are left with a welter of contradictory, inadequate, ad hoc explanations for world-wide patterns that have persisted for centuries, and that fall into almost perfect alignment when understood in the light of racial differences. How can so many people refuse to acknowledge the obvious? This review can do no better than end with Prof. Lynn’s own conclusion:

“The position of environmentalists that over the course of some 100,000 years peoples separated by geographical barriers in different parts of the world evolved into ten different races with pronounced genetic differences in morphology, blood groups, and the incidence of genetic diseases, and yet have identical genotypes for intelligence, is so improbable that those who advance it must either be totally ignorant of the basic principles of evolutionary biology or else have a political agenda to deny the importance of race. Or both.”