Race and intelligence
Theories about the possibility of a relationship between race and intelligence have been the subject of speculation and debate since the 16th century. Due to large influences of cultural Marxism on modern society, research into this possibility is often a taboo, sometimes even enforced by law (e.g., in France it is forbidden to take statistics by race).
One focus of the scientific debate is whether group IQ differences also reflect a genetic component. Hereditarianism hypothesizes that a genetic contribution to intelligence could include genes linked to neuron structure or function, brain size or metabolism, or other physiological differences that could vary with biogeographic ancestry. There is also debate about exactly how environmental factors play their role in creating the gap and the interrelationships between these factors.
HistoryIn the 19th and early 20th centuries racialist theories became quite popular, addressing the question of why certain races were not able to attain the same prosperity as Whites. The discussion on whether this had a biological foundation was not very common at the beginning as initial attempts to civilize other races (mainly Blacks and American Indians) were fruitless. The theory that there are differences in the brain sizes and brain structures that pertain to racial and ethnic groups was widely held and studied during this period.,,  Beginning in the 1950s, race difference research and hereditarianism (the belief that genetics is the primary cause of differences in intelligence among human groups) began to fall out of favor in psychology and anthropology, partly because of Allied victory in World War II against the Third Reich in Germany.
Debate from mid-20th-century to present timesThe contemporary debate on race and intelligence can be traced to a controversial article by psychologist Arthur Jensen called "How Much Can We Boost IQ and School Achievement?"
In the 1980s William Shockley postulated, based on the research of Cyril Burt, that the higher rate of reproduction among African Americans in the United States was having what he termed a "dysgenic" effect (meaning an opposite of eugenics); especially as influenced by welfare subsidies (e.g., AFDC), which he opined, unintentionally encouraged childbearing by what he called less productive mothers. Shockley proposed that individuals with IQs below 100 be paid to undergo voluntary sterilization.
Press attention returned again to the issue of race and intelligence in 1994 with the publication of The Bell Curve, by Charles Murray and the late Richard Herrnstein, which included two chapters on the subject of racial difference in intelligence and related life outcomes. The book asserted that the gap in black and white IQ scores was probably, in part, genetic. It received a great deal of publicity, including cover stories in Newsweek The New Republic, and The New York Times Book Review. Its politically incorrect views elicited much criticism.
Professor Emeritus Tatu Vanhanen, father of the Finnish Prime Minister Matti Vanhanen, told in an interview with Kuukausiliite, a monthly magazine supplement of Helsingin Sanomat, that African poverty is not the fault of the white man. "Whereas the average IQ of Finns is 97, in Africa it is between 60 and 70. Differences in intelligence are the most significant factor in explaining poverty", Vanhanen said in July 2007. Finnish police considered whether to launch a criminal investigation of Professor Vanhanen for his comments on IQ, race, and the wealth of nations in a magazine interview.
In 2007, the Nobel Prize winning biologist James Watson annoyed many anti-racists when he said that he was "inherently gloomy about the prospect of Africa" because "all our social policies are based on the fact that their intelligence is the same as ours - whereas all the testing says not really"
ResearchReferences to scientific papers such as Lynn 1991 are here
Test dataTest data has consisted of IQ tests, reaction speed tests, measurement of brain size, and how these relate to race, culture and upbringing, including factors like the proportion of Negro admixture in children of mixed White and Negro heritage.
The modern controversy surrounding intelligence and race focuses on the results of IQ studies conducted during the 20th century, mainly in the United States and some other industrialized nations. In almost every testing situation where tests were administered and evaluated correctly, the mean IQ of Blacks was approximately one standard deviation below that of Whites.
Much of the research on intelligence currently cited is based on IQ testing in the United States. This is due primarly because the United States has a tradition of classifying people by race, so a great amount of data can be retrieved from governmental statistcs which concern the whole population.
Attempted world-wide compilations of average IQ by race generally place Ashkenazi Jews and East Asians at the top, followed by Whites, Arabs and Native Americans, sub-Saharan Africans and Australian Aboriginals.>
Gaps are seen in other tests of cognitive ability or aptitude, including university admission exams such as the SAT and GRE as well as employment tests for corporate settings and the military (Roth et al. 2001). Measures of school achievement correlate fairly well with IQ, especially in younger children. In the United States, achievement tests find that by 12th grade Black students are performing on average only as well as White students in 10th grade, and Asian students in 8th grade; Hispanic students do only slightly better than Blacks. Whether the gaps are narrowing or not is debated.
Depending on the way intelligence is measured a variety of gaps may be found between different racial and ethnic groups. Some groups that perform well on one task may do poorly on others. For example, Moroccan and North American individuals were asked in a study by Richard K. Wagner to remember patterns of Oriental rugs and pictures of everyday objects, such as a rooster and a fish. Moroccans, who have long experience in the rug trade, seemed to remember rug patterns better than the North American individuals. Likewise, in 1979 Robert Serpell had Zambian and English children perform a number of tasks. He found that English children did better on a drawing task, but that Zambian children did better on a wire-shaping task.
Over the years, there has been variation in both the observed average IQ of groups, as well as the relative relationships between the average IQ of groups. Early 20th century measures typically found Blacks on the low end, and Whites on the high end. Based on studies from the 1960s and 1970s, Flynn found a slightly lower average IQ of Japanese- and Chinese American children compared to White counterparts, albeit with a significantly higher standard deviation. Recent contemporary measures place Blacks on the low end, and Asians on the high end. In the United States, based on a national assessment of adult literacy African Americans improved their scores more than any other racial/ethnic group in the years between 1992 and 2003. The survey measured three elements of literacy: prose, document, and quantitative literacy--which are reading, synthesizing information from documents and graphs, and basic math.
Attempted compilations of average IQ scores by race published by Richard Lynn in Mankind Quarterly and Murray, C. and Herrnstein, R. J. in their book The Bell Curve place Ashkenazi Jews and East Asians at the top, followed by Whites, Arabs and Native Americans, sub-Saharan Africans and Australian Aboriginals. 
GypsiesAccording to numerous studies, Gypsies have a significantly lower IQ than the average of the White race. In each case, when a study was conducted comparing intelligence of Gypsies and Whites, racial differences were found and Gypsies turned out to be less intelligent than Whites. From what can be infered from various studies, the average IQ of Gypsies would be about 80 (close to IQ of African-Americans); however, no united opinion exists.
During a Slovak study in the 90's, 23 510 childred in the age of 6 – 14 years in the district of Banská Bystrica, Slovakia, were given a Wechsler Scale test. A total of 510 children (2,16 %) were diagnosed as mentally retarded (with an IQ 70 or less). 0,9 % of the non-Gypsies were diagnosed as mentally retarded, as opposed to 21,5 % Gypsies. Although the Gypsy children constituted only 6 % of the testing sample, they counted for 60,7 % of the mentally retarded. 
Reaction timeIn 1991, Richard Lynn tested 1,468 9-year old children consisting of Blacks from South Africa, East Asians from Hong Kong and Japan, and Whites from Britain and Ireland. The content of the tests involved flipping a switch after one or more lights came on. Lynn found that the decision times (the time taken to make a decision about what to do) had a correlation of .65 with IQ data on Raven's Progressive Matrices tests also administered during the same study, and that movement times (the time taken to execute the decision) did not show any correlation. He found that the Asians had the fastest decision times, followed by the Whites, and then by the Blacks. He also determined that the Black children had movement times that were substantially faster than those of Whites and Asians on certain tests. Studies by Jensen have shown similar patterns in response time on tests of arithmetic and international studies by Lynn have also asserted the same trend.
Jensen 1993 has stated that this allows for an extension of Spearman's hypothesis to include reaction time. Based on these results, they have concluded that the observed East Asian-White-Black test differences have a neurological basis. Differences have been found between the reaction times of ethnic groups. In a study by done by Dennis Saccuzzo on information-Processing for African-American, Latino, Filipino, and White elementary school children enrolled in gifted versus non-gifted school programs, gifted African-Americans showed the fastest reaction times of the ethnic groups tested while nongifted African-Americans showed the slowest. The study, however, found only a "modest" correlation between reaction time and IQ.
Average racial differences have been asserted to exist on tests of response time, although it is also argued that some of these differences can be explained by cultural phenomena. Jensen has used reaction time as a proxy for IQ, despite the low correlation with IQ. The use of reaction time as a proxy for race has been disputed by others in the field. Leon J. Kamin and Sharon Grant-Henry used Jenson's work as an example of "claims about racial differences in intelligence that are not supported by scientific evidence" in their study Reaction Time, Race, and Racism.
Brain size and structureMany studies report that IQ has a moderate correlation with various measures of brain size. For example, a 2005 meta-analysis found that brain size correlates with IQ by a factor of approximately .40 among adults. The correlation was also found in some studies to hold true within families (where environmental factors can be considered to be similar), but in one study of 36 sibling pairs essentially zero correlation between brain size and IQ was found when comparing within families.
A correlation of 0.4 explains only 16% of the variance in IQ. In principle, assuming brain size and IQ are related, then all environmental factors that can affect IQ can also affect brain size. Better nutrition can affect brain growth, as can cognitive stimulation. A larger brain is not by itself evidence for genetics any more than IQ scores are.
Some historical and modern studies, using skull and head measurements, weighing of brains at autopsy, or more recently, magnetic resonance imaging, report racial differences in average brain size similar to those for IQ. Other studies have not found these results.
Professor Ulric Neisser (1997) states that the studies comparing brain size by race "exhibit many internal inconsistencies (and the within-groups variabilities are always much larger than the between-groups differences), there is indeed a small overall trend in the direction they describe. Even taken at face value, however, such a trend hardly constitutes evidence for a genetic interpretation".
There are several hotly debated studies which have concluded that there are race differences in brain size. These studies are criticized as having not found racially-based difference, with critics arguing instead the the variation better explained in terms of geography. A biogeographical variation in brain size is widely described as an evolutionary adaptation to climate. Lieberman (2001) states "...the relationship between latitude and cranial size is an example of Bergmann’s principle that crania are more spherical in cold climates because mass increases relative to surface area to conserve core temperatures...80 percent of body heat may be lost through our heads on cold days." Lieberman and other anthropologists have also made several other criticisms of claims of racial differences.
In 1970 Philip V. Tobias listed a number of difficulties involved in measuring and making meaningful comparisons of brain weight. These included equating subjects on age, sex, body size, temperature etc. In addition, brain development is plastic, and brain size may be affected by early environmental factors. Because of all these difficulties, Tobias concluded that no adequate racial comparative studies had actually been conducted. The brain size of American Blacks reported in Tobias’s summary were larger than any White group, (which include American, English and French Whites) except those from the Swedish sub sample (who had the largest brains of any of the 77 national groups measured), and American Blacks were estimated to have some 200 million more neurons than American Whites (See Tobias 1970; Weizmann et. 1990).
One other study showing similar patterns in average brain weight is Ho et al. 1980 which analyzed autopsy records from Case Western Reserve University (N=1,261) to determine the effects of age, gender, and race on brain weight. The authors found that while there was a large amount of overlap among the groups, there were also statistically significant differences between the groups, and found that White males had the largest brain weight, followed by Black males, White females, and Black females. Ho et al. 1980 also discovered that mean brain mass decreased over a five year period fastest for White males, followed by Black males, White females, and Black females.
Perhaps the largest single study, Beals et al. 1984 analyzed more than 20,000 skulls from around the world, finding that brain size varied with latitude. "Beals, Smith, and Dodd emphasize that this relationship is independent of 'race'."
|External head measurements||1335||1341||1284|
|Corrected for body size||1356||1329||1294|
|Redrawn from Jensen 1998b, Table 12.1|
|Source: Rushton 2000|
Other studies have shown the same pattern in average head size, including Rushton 1992, Rushton 1994, and the National Collaborative Perinatal Project (described by Broman et al. 1987) which collected anthropometric data, including head measurements and IQ, on approximately 35,000 children from 1959 to 1974 (although the study began with over 50,000 subjects, some attrition occurred as with many longitudinal studies). Analyses of the data found the East Asian ? White ? Black pattern in head size and IQ at 4 months, 1 year, and 7 years of age.
According to Lieberman, Rushton and others combining the correlations between race, IQ and brain size to establishes a correlation between race and IQ. This conclusion is strongly objected to by Lieberman and other scientists, both on the basis of the initial correlation asserted between race and brain size, and the progressively weak correlation as the studies are combined.Jensen's use of "brain size" as a proxy for intelligence was criticized by Ty Partridge.
Several of the indices reported by Jensen are of questionable validity ... For example, correlations between head circumference or global brain volume and intelligence are unreliably reported in the literature. Head circumference is such a gross measure of cranial capacity that it is hardly useful. Intracranial endocasts are often used to determine the cognitive capabilities of early hominids; however, this is due primarily to the lack of more accurate measures rather than the validity of the method...Indeed there is ample evidence that simple measures of brain size are of little utility in understanding individual differences in "intelligence".Mongoloid brains have greater width and breadth (i.e., are more brachycephalic) and are more spherically shaped than those of Europeans (it should be noted that theirs has more angles or a diamond shape, as well as a more developed frontal region of the skull). Negroids tend to have longer and narrower (more dolichocephalic) brains.Beals et al. proposed that the longer and narrower African brain evolved for better heat dissipation in a warmer climate, while East Asians and Europeans evolved comparatively shorter and wider brains for thermoregulatory purposes in a cooler climate. Rushton and Ankney 2000 (pp. 612-613) question the thermoregulatory hypothesis, instead positing that brachycephalization and sphericalization allow for greater brain size. At the same time, Rushton and Ankney believe it is possible that the need to thermoregulate in Africa may have selected against increasing brain size. Rushton and Ankney 2000 found a pattern of descending prognathism, glabella size, postorbital constriction, and temporal fossae in African, European, and East Asian skulls and propose that these structures shrank over the course of evolution to allow greater brain size.
Rushton has been accused by other researchers of misrepresenting the data. When they have reanalyzed the data, Zack Cernovsky et al. argue that many of Rushton's claims are incorrect. Extensive statistical analyses by Beals et al. showed that cranial size varies primarily with climatic zones (e.g.,distance from the equator), not race. According to Beals et al., the correlations of brain size to race are spurious: smaller crania are found in warmer climates, irrespective of race. Several other studies found that North American Blacks were superior to American Whites in brain weight, that they had cranial capacities that compared favorably to the average for various samples of Caucasians, and that they had excess neurons larger than many groups of Caucasoids, for example, the English and the French. In general, skulls from people in countries with poverty and infant malnutrition are smaller regardless of race. Cernovsky argues that it is only by pooling their data with data for Negroids from countries in hot climatic zones (notorious for famine and infant malnutrition) that Rushton obtained an illusory support for his postulates.
In a 2005 review of the literature , Rushton and Jensen claim that MRI studies show racial differences in brain size. The cited study (Harvey et al. 1994) compared brain size between a group of 26 persons with bipolar disorder and a group of 48 persons with schizophrenia and also included 34 healthy controls. The distribution of age and race was approximately equal across the three groups and consisted of Caucasians, Blacks, and West Indians (p. 692, table 1). Harvey et al. write,
Over the entire sample intracranial volume was related to height (P=0.0001), gender (P=0.001), ethnicity (P=0.007), and IQ (P=0.03), but not age; larger volumes generally occurred in those subjects who were taller, male, and Caucasian" (p. 693).(Note that East Asians were not included in the study, that there was a sex ratio imbalance among the schizophrenic group (p. 692), that intracranial volume is not the same thing as brain size, and that the sample where most have serious mental disease may not be representative for population as a whole.) Possibly related to the Flynn effect is, as also previously observed by Boas, increase in cranial vault size and change in shape during the last 150 years in the US. Cranial vault size and shape have changed greatly during the last 150 years in the US. These changes must occur by early childhood because of the early development of the vault. The explanation for these changes may be related to the Flynn effect. Brain size has increased for both American Blacks and Whites probably due to improved health and nutrition.
Admixture and trans-racial adoption studies
United States of AmericaThere is agreement that the U.S. Black-White gap among children and adolescents on achievement tests narrowed in the 1970s and 1980s, but stalled during the 1990s. On the basis of these data, Nisbett 2005 argues that the gap in g has also narrowed to "0.6-0.7 standard deviation or approximately 10 IQ points". Both Rushton and Jensen 2005b and Gottfredson 2005b argue that "gains in scholastic achievement do not equal gains in g, and the Black-White differences in g are as large as ever, even for measures of reaction time". Charles Murray argues that the U.S. Black-White gap on the SAT has increased in size to 1 SD from the 1990s to 2005.
Measures of school achievement correlate fairly well with IQ (uncorrected correlations are highest for younger children because of restricted ranges of IQ at higher educational levels). The National Assessment of Educational Progress in the United States, find that by 12th grade Black students are performing on average only as well as White and Asian students in 8th grade; Hispanic students do only slightly better than Blacks. Closing this achievement gap is one of the aims of the No Child Left Behind act in the United States. The gap has been attributed to academic disengagement of Black students and parents and to environmental causes. Poverty in early childhood has long-lasting negative consequences for cognitive development and academic outcomes, as shown by numerous studies.
United Kingdom of Great Britain and Northern IrelandIn a recently publicized 2005 study Deborah Wilson, Simon Burgess and Adam Briggs found that in the UK, Black children enter school at the same level as their White peers, if one controls for a number of covariates. Black children then fall behind, even controlling for covariates, in the first two years of schooling, and stay behind until secondary school where they make greater progress then their White peers substantially, but not completely closing the gap. "This suggests more systemic factors. One such often proposed is the importance of aspirations and values inculcated by families and reinforced by communities. This involves the importance of education in general, and the role of education in getting on." In the later years of schooling the study found that White pupils make slower progress than other ethnic groups.
Group mean IQ from various sourcesNOTE: The information in the following tables is referenced to credible sources; however, it should be noted that some of these studies synthesized their results from different sources and test methods. In general comparisons should only be made between similar primary sources.
|Richard Lynn, |
"Race Differences in Intelligence: An Evolutionary Analysis" 2006
Table 16.2 (indigenous populations)
|Native Americans (north & south)||86|
|Southern Asian & Northern Africans||84|
|Native Australians (aboriginals)||62|
|Bushmen (southern Africa)||54|
Also see: Race and intelligence (test data) (Wikipedia article).
ExplanationsThose arguing for a genetic contribution towards differences in intelligence between races do not exclude other possible influences the way that the hereditarian hypothesis is excluded. The genetic explanation is the controversial one. Proponents of the view that the IQ gap is caused partly by genetic differences do recognize that non-genetic factors are also involved.
GeneticsSome of the notable proponents of the partly genetic hypothesis are Raymond B. Cattell, Arthur Jensen and Hans Eysenck who was the most cited living psychologist at the time of his death and and the third most cited psychologist of all time (after Sigmund Freud and Jean Piaget). Evidence in favour of a genetic contribution includes trans-racial adoption studies.
Rushton and Jensen examined 10 categories of research evidence from around the world to contrast "a hereditarian model" (50% genetic-50% cultural) and a culture-only model (0% genetic-100% cultural). In the article "Thirty Years of Research on Race Differences in Cognitive Ability" published in the APA journal Psychology, Public Policy and Law they cite the following evidence to support the hereditarian model:
1) The Worldwide Pattern of IQ Scores. East Asians average higher on IQ tests than Whites, both in the U. S. and in Asia, even though IQ tests were developed for use in the Euro-American culture. Around the world, the average IQ for East Asians centers around 106; for Whites, about 100; and for Blacks about 85 in the U.S. and 70 in sub-Saharan Africa.
2) Race Differences are Most Pronounced on Tests that Best Measure the General Intelligence Factor (g). Black-White differences, for example, are larger on the Backward Digit Span test than on the less g loaded Forward Digit Span test.
3) The Gene-Environment Architecture of IQ is the Same in all Races, and Race Differences are Most Pronounced on More Heritable Abilities. Studies of Black, White, and East Asian twins, for example, show the heritability of IQ is 50% or higher in all races.
4) Brain Size Differences. Studies using magnetic resonance imaging (MRI) find a correlation of brain size with IQ of about 0.40. Larger brains contain more neurons and synapses and process information faster. Race differences in brain size are present at birth. By adulthood, East Asians average 1 cubic inch more cranial capacity than Whites who average 5 cubic inches more than Blacks.
5) Trans-Racial Adoption Studies. Race differences in IQ remain following adoption by White middle class parents. East Asians grow to average higher IQs than Whites while Blacks score lower. The Minnesota Transracial Adoption Study followed children to age 17 and found race differences were even greater than at age 7: White children, 106; Mixed-Race children, 99; and Black children, 89.
6) Racial Admixture Studies. Black children with lighter skin, for example, average higher IQ scores. In South Africa, the IQ of the mixed-race "Colored" population averages 85, intermediate to the African 70 and White 100.
7) IQ Scores of Blacks and Whites Regress toward the Averages of Their Race. Parents pass on only some exceptional genes to offspring so parents with very high IQs tend to have more average children. Black and White children with parents of IQ 115 move to different averages--Blacks toward 85 and Whites to 100.
8) Race Differences in Other "Life-History" Traits. East Asians and Blacks consistently fall at two ends of a continuum with Whites intermediate on 60 measures of maturation, personality, reproduction, and social organization. For example, Black children sit, crawl, walk, and put on their clothes earlier than Whites or East Asians.
9) Race Differences and the Out-of-Africa theory of Human Origins. East Asian-White-Black differences fit the theory that modern humans arose in Africa about 100,000 years ago and expanded northward. During prolonged winters there was evolutionary selection for higher IQ created by problems of raising children, gathering and storing food, gaining shelter, and making clothes.
10) Culture-only theories do not explain the highly consistent pattern of race differences in IQ, especially the East Asian data. No interventions such as ending segregation, introducing school busing, or "Head Start" programs have reduced the gaps as culture-only theory would predict.
Some scholars have proposed that in order to make a racial hypothesis about intelligence the genes for intelligence need to be identified along with their frequencies in the various populations. However recent studies attempting to find regions in the genome relating to intelligence have had little success. A recent study used several hundred people in two groups, one with a very high IQ, average 160, and a control group with an average IQ of 102. The study used 1,842 DNA markers and put them through a five step inspection process to eliminate false positives. By the fifth step the study could not find a single gene that was related to intelligence. Critics of these studies say the failure to find a specific gene associated with intelligence is indicative of the complex nature of intelligence. They contend that intelligence is probably under the influence of several genes. Some estimate that as much as 40% of the genome may contribute to intelligence.
Recently scientists at the University of Chicago identified two genes, microcephalin and ASPM. Mutations in these genes are associated with brain size abnormality, microcephaly . The normal variants are found at high frequencies in Asian and European populations but they are not found among Sub-Saharan Africans. The scientists stated that microcephalin may have arisen some 37,000 ago coinciding with upper paleolithic transitions in Europe. They also stated that a variant of APSM arose about 5,800 years ago roughly correlating with the development of written language, spread of agriculture and development of cities. They thus believe these two genes conferred some cognitive abilities upon Asians and Europeans.  These studies have been criticized saying it was far from clear that the new alleles conferred any cognitive advantage or had spread for that reason.
Other scholars have criticized the University of Chicago scientists because they made claims about these genes without undertaking any direct experimentation to test their hypothesis on increased intelligence and brain size. Subsequently when these experiments were done, no relationship was found between these genes and intelligence or brain size. 
CultureBlacks in Africa score much lower than Blacks in the US. The majority of blacks enrolled in Ivy League Universities in the US are either from Africa or the Caribbean. Notable examples include Barack Obama and his father Obama Sr. The Black economist Thomas Sowell argues that dysfunctional Black culture is the reason for the low IQ and poor academic performance of Black Americans.
It has been suggested that Black culture disfavors academic achievement and fosters an environment that is damaging to IQ (Boykin, 1994). It is also argued that discrimination against Blacks on account of their race reinforces this negative effect. John Ogbu (1978, 1994) has hypothesized that the condition of being a minority affects motivation and achievement, depressing IQ. Some anthropologists have argued that intelligence is a cultural category; some cultures emphasize speed and competition more than others, for example.
The Flynn effect is often cited as evidence that average IQ scores have changed greatly and rapidly, for reasons poorly understood, noting that average IQ in the US may have been below 75 before the start of this effect, and thus some argue that the IQ gap between races could change in the future or is changing, especially if the effect started earlier for Whites.
Environmental factorsPoor health and nutrition may depress IQ in poorer countries. It has been proposed that greater rates of low-birth-weight babies and lower rates of breastfeeding in Blacks as compared to Whites affect the IQ gap.
In the US, Critics of these studies also say that as long as social and environmental disparities between the races exist it will be impossible to scientifically test whether there are any genetic differences in IQ between the various populations. They propose that if the historical effects of poverty and social bigotry were eliminated and differences in IQ between the races still persisted then there might be some utility in such research.
Achievements of societiesSome people have attributed differential economic growth between nations to the differences in the intelligence of their populations. One example is Richard Lynn's IQ and the Wealth of Nations. The book is criticized in the peer-reviewed paper The Impact of National IQ on Income and Growth. Another peer-reviewed paper, Intelligence, Human Capital, and Economic Growth: An Extreme-Bounds Analysis, finds a strong connection between intelligence and economic growth. It has been argued that East Asian nations underachieve compared to IQ scores.
Jared Diamond's Guns, Germs and Steel instead argues that historical differences in economic and technological development for different areas can be explained by differences in geography (which affects factors like population density and spread of new technology) and differences in available crops and domesticatable animals. Psychologist John Philippe Rushton suggests these environmental differences may operate in part by selecting for higher levels of IQ.
Governmental policySome educators believe that efforts should be made to eliminate the intelligence gap changing the distribution of funding for education.
Some proponents of a genetic interpretation of the IQ gap, such as Template:A(Y)ref and Template:A(Y)ref, have sometimes argued that their interpretation does not in itself demand any particular policy response.
Herrnstein and Murray 1994 wrote: "We can imagine no recommendation for using the government to manipulate fertility that does not have dangers. But this highlights the problem: The United States already has policies that inadvertently social-engineer who has babies, and it is encouraging the wrong women. If the United States did as much to encourage high-IQ women to have babies as it now does to encourage low-IQ women, it would rightly be described as engaging in aggressive manipulation of fertility. The technically precise description of America's fertility policy is that it subsidizes births among poor women, who are also disproportionately at the low end of the intelligence distribution. We urge generally that these policies, represented by the extensive network of cash and services for low-income women who have babies, be ended. (p. 548)"
While not specifically race-related, policies focused on geographical regions or nations may have disproportionate influences on certain racial groups and on cognitive development. Differences in health care, nutrition, regulation of environmental toxins, and geographic distribution of diseases and control strategies between the developing world and developed nations have all been subjects of policies or policy recommendations (see Health and intelligence).
Gregory Stock, writes that germinal choice technology may one day be able to select or change directly alleles found to influence intelligence or racially identifying traits, making them susceptible to biotechnological intervention.