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The race and intelligence debate is a controversial issue, where considerations on both the nature of race and the meaning and measurement of intelligence have the potential to pre-empt the entire debate, according to many scholars. Important related questions include whether intelligence can be accurately described by a single number, and whether the nature of intelligence is the same across cultures, as well as ambiguities in the use of "race" as it is commonly understood to classify humanity.

At the base of the debate is the observation that intelligence quotient (IQ) tests have demonstrated significant differences in the average scores of different population groups, particularly US Blacks and Whites (racially self-identified for the most part). No consensus exists regarding the meaning and/or relevance of these differences, and numerous interpretations have been proposed to clarify them. A particularly controversial facet of this debate is the relative degree to which the development of intelligence is affected by genetic factors on the one hand and environmental factors on the other.

Within individuals, some factors of intelligence are clearly affected by genetics. However, no set populations of humans have been demonstrated to have significant genetic differences that would affect the average group intelligence. Also part of the debate is whether measures such as IQ can meaningfully quantify such differences, and whether it would be beneficial or ethical to study differences if they did exist. Various explanations for racial group differences have been proposed, such as the effect of a population's health, differences in education quality, sub-conscious psychological factors, and institutional racial discrimination. While environmental differences could statistically account for differences in test scores, no specific environmental factor has been identified as a definitive cause, and no direct evidence exists for genetic factors.

Although research and debate on race and intelligence encompasses a variety of topics, the nature versus nurture question attracts the most public attention.

Overview

In 1995, a task force of the American Psychological Association (APA) headed by psychologist Ulric Neisser published a report entitled Intelligence: Knowns and Unknowns which intended to present a summary of the findings of scientific research regarding intelligence, which also commented upon the topic of race and intelligence. According to this report, psychometric testing, despite being one of the most fruitful approaches to studying intelligence, has yet to produce answers to many questions regarding intelligence. Though psychometricians have devised ways to measure the distinct yet intercorrelated abilities believed to play an important role in the development of intelligence, the correlations between those abilities remain largely unclear. As intelligence test scores correlate moderately well with measures of educational success, it is apparent that such tests measure important skills. However, noted the authors, educational achievement is not primarily determined by intelligence, though intelligence test scores do correlate significantly with occupational status later in life.

The APA report further noted that, while both genetic and environmental variables are involved in the manifestation of intelligence, the role of genetics has been shown to increase in importance with age. Why this happens in not yet understood, and the question as to what role the environment plays in this increase remains unanswered. Nonetheless, there are several important environmental factors which are known to affect the development of intelligence, such as formal education and general health. The much-discussed "Flynn effect", which refers to the striking worldwide mean IQ increase of 15+ points over the last 50 years, may be the result of similar environmental factors such as improved nutrition, cultural changes, improvement in the administration of tests, changes in educational practices or some other hitherto unrecognized factor.

On the topic of race and intelligence, the APA task force wrote that, as the measured differences in intelligence between various ethnic groups is the result of complex patterns, any conclusions which require broad generalizations run the risk of oversimplifying the issue as well as misrepresenting the available data. At the same time, intelligence test scores in some minority populations are reasonably good indicators of educational achievement levels in later life. The long-standing 15+/− point difference between the intelligence test scores of African Americans and White Americans, though it might have narrowed somewhat in recent years, remains unaccounted for despite proposed explanations claiming systematic bias, differences in culture or socioeconomic status (SES), or genetics as the sole underlying cause.

Suitability for study

Some scholars have expressed the view that the study of race differences in intelligence is meaningless, unethical or both. This is an on-going debate with proponents and opponents of this view making statements in the academic literature in support of their respective positions.

For example, according to Robert Sternberg and colleagues, intelligence (often approximated using IQ) is not a well defined construct, and IQ tests do not provide definitive measures of intelligence. They argue that race and ethnicity are socially defined groups—rather than biological observations—whose membership is not homogeneous; races and ethnicities are often defined by affiliation with very large geographical areas (Asian) or common language (Hispanic). For these reasons, they conclude that discussions of correlations between race and intelligence which extrapolate a genetic causation are fundamentally flawed.

In another example, Richard E. Nisbett and James Flynn, who each believe that the available evidence favors an entirely environmental explanation for differences in test scores between blacks and whites, nonetheless reject the argument that studying these differences is meaningless and also reject the argument that the research is unethical. Rather, each has endorsed the view that the cause of group differences can be resolved with empirical study. Flynn gives particular credit to Arthur Jensen for stimulating more rigorous research on the topic.

Test score differences

Most of the evidence of intelligence differences between racial and ethnic groups is based on studies of intelligence test scores. Intelligence tests measure many important abilities, such as verbal and quantitative reasoning, and can predict socially-relevant outcomes such as academic performance and occupational outcomes. However, intelligence test scores do not reflect all of the intricacies of the everyday meaning of intelligence, so researchers take care to distinguish between IQ test results and intelligence.

Some studies of intelligence tests use statistical methods to extract so-called latent variables from the IQ test scores. One such variable is the general intelligence factor, or g, which accounts for most of the differences in IQ test scores between individuals. There are other latent variables in addition to g, and IQ tests vary in their ability to measure these latent variables, if they measure them at all. IQ tests scores, while often summarized as a single overall number, are actually multidimensional in nature. Transforming IQ test scores into latent variables is an attempt to find one or more dimensions on which to compare IQ test scores.

Latent variables are also sometimes called factors or constructs. The construct validity of an IQ test score is a key criteria for judging whether the IQ test score differences are meaningful. Tests which do not measure difference in latent variables for some group are said to have measurement bias. The construct validity of most commonly used IQ tests has been fairly well established within multiple racial-ethnic groups in developed countries such as the United States. That is, test score differences within each racial-ethnic group are valid indicators of differences in latent variables such as g. A related question is whether test-score differences between groups are valid. There is a consensus that test score differences between Black and White people in the US have predictive validity (also called predictive invariance), meaning that test scores predict the same socially-relevant outcomes regardless of the race of the person being tested. To further address this question, three studies using sophisticated statistical techniques have shown that Black-White differences in IQ test scores are not a result of measurement bias (a criteria called measurement invariance). These studies imply that Black-White IQ differences reflect very general differences in some underlying latent variables, but they are unable to differentiate precisely which latent variables differ under a variety of models. These studies were performed in response to previous investigations which suggested that Black-White IQ differences are primarily differences in g in particular.

United States

There are observed differences in average test score achievement between racial-ethnic groups, which vary depending on the populations studied and the type of tests used. Self defined black and white United States citizens have been the subjects of the greatest number of studies. Black-White average IQ differences appear to increase with age, reaching an average of nearly 17 points by age 24, which is slightly more than 1 standard deviation. According to James Flynn and others, the overall average Black-White gap has reduced by one third over the course of the 20th century. For example, the black men inducted into the US armed forces during World War II averaged about 1.5 standard deviations below their white counterparts. This improvement is also reflected in Black-White differences on school achievement tests, which have shrunk from about 1.2 to about 0.8 standard deviations. However, these improvements may have stalled for people born after the early 1970s.

The average black-white IQ difference also varies depending on test content. For example, two subsections of the WISC IQ test, known as forward and reverse digit-span, ask children to repeat a long series of numbers either forwards or backwards. The black-white difference on forward digit span is relatively small, while the difference on reverse digit span is relatively large. Across a battery of tests, the size of the Black-White gap is correlated with the extent to which the tests measure the psychometric factor g, which also accounts for most of the variation in interindividual differences in IQ test performance. 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.

The IQ distributions of other racial and ethnic groups in the US are less well studied. Hispanic and Native American populations, including Arctic Natives, tend to score worse on average than White populations but better on average than Black populations. East Asian populations may score higher on average than White populations in the US as they do elsewhere. A 1960 study of 1236 American teenagers calculated six IQ measures for Jews relative to white Gentiles. The results found that the relative IQ of American Jews varied from a low of 91.3 (visual reasoning) to a high of 109.7 (mathematics). A recent review by Lynn (2004) used a 10 word vocabulary test to estimate the IQ of American Jews. The population of 150 Jews scored half a standard deviation above the 5300 white Gentiles in verbal IQ.

For each of these populations, there is some evidence that the mixture of ability factors that distinguish individuals are differentially distributed between groups. For example, East Asian populations tend to outscore White populations in performance IQ, whereas the test score differences skew towards higher verbal IQ for Ashkenazi-White differences. However, the mixture of abilities within groups appears to be nearly identical across many ethnic groups. The stability of these differences is also less well studied than Black-White differences.

Worldwide

According to Richard Lynn, J. Philippe Rushton, and others, IQ test score differences are observed cross-culturally and around the world. Lynn has published three books summarizing IQ test scores from around the world. The inaccuracy of the cross cultural IQ scores is well documented, but many scholars use the results as an estimate of worldwide IQ scores. Lynn's meta-analysis lists East Asians (105), Europeans (99), Inuit (91), Southeast Asians and Amerindians (87 each), Pacific Islanders (85), South Asians/North Africans (84), Non-Bushmen sub-Saharan Africans (67), Australian Aborigines (62) and Bushmen (54). International achievement test scores, including TIMSS and PISA, have also been used to estimate average IQ worldwide with similar results where data is available.

The very low IQ scores reported for sub-Saharan African populations are especially controversial. For example, Wicherts argues that the average IQ of sub-Saharan Africans is poorly measured and is more likely 78. According to anthropologist Mark Cohen, the frequently reported African mean IQ of 70 is "preposterous". Using Western standards, this would mean that African countries evidencing such a low IQ would be largely dysfunctional. Given that individuals in these countries lead "vibrant artistic, symbolic and spiritual lives", this is, according to Cohen, clearly not the case. Thus, he concludes, the IQ test results from Africa do not reflect actual intelligence levels.

Differences in education, prolonged malnutrition, exposure to toxin, exposure to stress, and exposure to disease are all generally expected to contribute to the lower scores observed in developing countries. However, direct experimental evidence to confirm the role of individual factors is difficult to acquire in most cases because each of these factors tends to also be associated with one another and with unfavorable socioeconomic conditions. In the case of some toxins, such as lead, a negative effect on IQ scores has been established. Two other factors that have as well established negative association with IQ are severely premature birth and severe low birth weight.

Hypotheses

The cause(s) of group average IQ test score differences are not known but hypotheses have been proposed. Many scholars have offered descriptions of the variety of hypotheses that have been proposed. These descriptions usually distinguish between those hypotheses which invoke a major contribution of genetic factors (hereditarian) and those which invoke mainly environmental (i.e., non-genetic) factors. Some descriptions of the positions are themselves controversial.

In a review published in 2007, Hunt and Carlson categorized four explanations for observed differences in IQ scores between groups. The strongest hereditarian position, attributed to Jensen and Rushton, is that group differences in IQ reflect differences in intelligence that are "due in substantial part to genetically determined differences in brain structure and/or function". A second position, attributed to Ogbu and Sowell, is that the differences in intelligence test scores are due to social factors. Third, Sternberg and colleagues are attributed with the view that the use of IQ scores to argue for differences in intelligence is an inappropriate use of tests in different groups. The fourth position, attributed to Fish and others, is that there is no such thing as race: "a term motivated by social concerns and not a scientific concept".

Socioeconomic factors

According to the report of a 1996 APA task force, socioeconomic factors (SES) cannot be the whole explanation for racial-ethnic group differences in IQ. Their first reason for this conclusion is that the black-white test score gap is not eliminated when individuals and groups are matched on SES. Second, excluding extreme conditions, nutritional and biological factors that may vary with SES have little effect on IQ. Third, the relationship between IQ and SES is not simply one in which SES determines IQ, rather it is more likely that intelligence causes differences in SES than the other way around. Lastly, they argue that income and education simply fail to capture important categories of cultural experience which differ between racial and ethnic groups.

Stereotype threat

Stereotype threat is the fear that one's behavior will confirm an existing stereotype of a group with which one identifies; this fear may in turn lead to an impairment of performance. Testing situations that highlight the fact that intelligence is being measured tend to lower the scores of individuals from racial-ethnic groups that already score lower on average. Stereotype threat conditions cause larger than expected IQ differences among groups but do not explain the gaps found in non-threatening test conditions.

Flynn effect

The secular, international increase in test scores, commonly called the Flynn effect, is seen by Flynn and others as reason to expect the eventual convergence of average black and white IQ scores. Flynn argues that the average IQ scores in several countries have increased about 3 points per decade during the 20th century, which he and others attribute predominantly to environmental causes. This means, given the same test, the mean performance of African Americans today could be higher than the mean for white Americans in 1920, though the gains causing this appear to have occurred predominantly in the lower half of the IQ distribution. If an unknown environmental factor can cause changes in IQ over time, they argue, then contemporary differences between groups could also be due to an unknown environmental factor.

Nichols (1987) critically summarized the argument as follows:

(1) We do not know what causes the test score changes over time. (2) We do not know what causes racial differences in intelligence. (3) Since both causes are unknown, they must, therefore, be the same. (4) Since the unknown cause of changes over time cannot be shown to be genetic, it must be environmental. (5) Therefore, racial differences in intelligence are environmental in origin (p. 234).

Flynn and other researchers have found reason to doubt the construct validity of secular increases in IQ scores. In terms of the latent variables that IQ tests were designed to measure, such as g and verbal and mathematical ability, changes in IQ scores over time are different than either within-group individual differences and between-group differences. For example, there has been little increase over time in performance on either the forward digit-span or reverse digit-span subtests, and tests of school achievement have been less affected than tests of abstract reasoning. At least one study has found that measurement bias contributes to the Flynn effect, which is not seen in black-white IQ differences.

Heritability

There is a consensus among intelligence researchers that IQ differences between individuals within the same population (usually self identified "Black" or "White" in studies) are significantly heritable. It should be noted that heritability is a property of a population and may vary significantly between populations.

Concordance rates for IQ from twin studies and other study designs consistently fall in the range of 30% to 80%, with the estimated heritability in young (preschool) children in the lower range and adults in the higher range.

Much of the research on explaining group differences stems from an observation promoted first by Arthur Jensen and later James Flynn and others regarding an environmental explanation for group differences. According to Jensen, the very high within-group heritability of IQ (within both white and black populations) presents a problem for environmental explanations of group differences in IQ. They consider two general classes of environmental factors: common environmental factors and X-factors. Common environmental factors vary within and between populations. X-factors vary between populations, but do not vary substantially within populations. They first consider common environmental factors. To account for a 1 SD B-W IQ gap only in terms of common environmental factors would require very large environmental differences. For example, if the within-group heritability of IQ is 80%, then a B-W IQ difference of 2.24 SD in common environmental factors is required. For a heritability of 40%, a difference of 1.29 SD is required. Jensen and Flynn agree that it is an empirical question whether common environmental factors that influence IQ differ between whites and blacks to such an extent, and both agree that most commonly suggested environmental factors do not. Jensen believes that empirical evidence supports the view that the B-W IQ gap is caused by both common environmental factors and genetic factors. Flynn disagrees and believes that empirical evidence supports the view that the B-W IQ gap is caused by yet unrecognized environmental factors.

The alternative to common environmental factors is the hypothesis that X-factors account for the B-W IQ gap. A frequently-cited example from Lewontin describes the effect of a hypothetical X-factor. Imagine that the height of "ordinary genetically varied corn" is 100% heritable when grown in a uniform environment. Further imagine that two populations of corn are grown: one in a normal nutrient environment and the other in a deficient nutrient environment. Consequently, the average height of the corn grown in the deficient nutrient environment is less than the average height of the corn grown in the normal environment. In such a scenario, the within-group heritability of height is 100% in both populations, but the substantial difference between groups is due entirely to environmental factors. The quality of the nutrient is an "X-factor" in the language of Jensen and Flynn. With respect to the B-W IQ gap, Jensen suggests that effects associated with racism (both overt and institutionalized racism) might be X-factors. Flynn believes that attributing the B-W gap to the effects of racism is incorrect, because the most plausible ways in which discrimination could affect IQ are themselves common environmental factors. These may include psychological effects such as stereotype threat; biological effects such as poor nutrition, health care and living close to toxic environments; and educational effects such as a lack of good schools. Instead, Flynn and his colleague William Dickens have developed more complicated models to explain the black-white gap in terms of environmental factors. One initial motivation of the Dickens-Flynn theory was Flynn's observation that IQ test scores have been rising over time in countries around the world—termed the Flynn effect. Flynn and others believe an explanation for the Flynn effect may elucidate the cause of the B-W gap. Jensen and others disagree.

Critics have also questioned the interpretation of heritability as a whole. Lewontin suggests that some genotypes are more influenced by environments than others, leading to the possibility that populations that have similar genetic variance in the same environment can have different heritabilities because of their different genotypes. David Layzer (1974) contends that the development of a trait can be influenced by genetic differences qualitatively and that heritability estimates cannot measure such qualitative differences, as such it is possible that even with a heritability of close to 100% it is possibly for phenotypic variance to be due largely to environment. As a comparison, schizophrenia is estimated to be at least 70% heritable, of which 30% of the actual genes have been accounted for.

Ten argument supporting the existence of race differences in IQ scores between whites and blacks

• 1. The two races have evolved independently of one another and in different environments over a period of one hundred thousand years. When two populations evolve in isolation from one another during such period there are differences that appear in all areas where there are possibilities of genetic variation. The extreme environmentalist position, assuming there are no intellectual differences between races defy the general principle of biological evolution and can be seen as impossible.
• 2. The Africans obtain an I.Q quite similar in many different locations: this must be regarded as evidence of a strong genetic factor.
• 3. The high heritability found among twins in America, Europe, Japan and India shows that intelligence is largely determined by genetic factors.
• 4.The cranial volume differences between Caucasian and black show the existence of genetic factors, because the heritability of cranial volume is 0.9 and the correlation between intelligence and cranial volume is 0.4.

• 5. Many egalitarians have suggested that white racism could reduce the IQ of blacks, but there is no explanation that can explain how racism might reduce IQ, and then why the IQ of black Africans in Africa would he 67? If racism diminishes intelligence, it is curious that the Jews of America and England have an IQ of 108, then they have been exposed to racism for centuries. The high IQ of American Jews is well known since 1930.
• 6. Black children adopted by white parents get the same scores as predicting racial. There is still difference of 17 IQ points between whites and blacks raised in the same conditions. Being raised by white adoptive parents had no positive effect on the intelligence of blacks.
• 7. The IQ of hybrids is intermediate between the two parental breeds, as well as the cranial volume, which is also the intermediary between the two parental breeds.
• 8. It has been shown a significant difference between races in terms of reaction time. The reaction time is correlated with IQ, because both of them are eficiente signs of central nervous system. The average Caucasian react more quickly to a stimulus.
• 9. The more white admixture, the greater the average brain weight of an African high (genetic testing beyond the color of the skin).
• 10. Racial differences in cranial capacity are correlated with 76 musculoskeletal traits identified in standard works of evolutionary anatomy as systematically related to an increase in cranial capacity in hominids.

Black and biracial children raised by white parents

Studies in which white parents raise black and biracial children have been variously regarded as inconclusive, supportive of an environmental interpretation, or supportive of a hereditarian interpretation. Three studies are commonly cited: the Minnesota Transracial Adoption Study, Moore (1986), and Eyferth (1961). The Moore and Eyferth studies have been criticized due to concern that children and parents in these studies are not representative for reasons such as their age and circumstances that led their inclusion in the studies. A similar study on black, white, and mixed-race children raised in educationally-enriched nursery groups is cited by Nisbett; the study found IQs at age 5 of 108 for black children, 103 for white, and 106 for mixed-race. Like Moore (1986), the IQ of the parents is unknown, and the results could be distorted by the selective migration of the West Indian parents of the black children.

African ancestry and IQ

African Americans typically have ancestors from both Africa and Europe, with, on average, 20% of their genome inherited from European ancestors. Several studies performed without the use of DNA-based ancestry estimation attempted to correlate estimates of African or European ancestry with IQ. These studies have been variously regarded as inconclusive, supportive of an environmental interpretation, or supportive of a hereditarian interpretation. These studies are generally criticized for using unreliable methods to estimate ancestry and for their small sample sizes.

Rowe (2005) and others have suggested using DNA-based methods to reproduce these studies with reliable estimates of ancestry. Such experiments have never been published, although the requirements for such a study have been discussed in the academic literature.

Molecular genetic studies

The decoding of the human genome has enabled scientists to search for sections of the genome that contribute to cognitive abilities. Current studies using Quantitative trait loci have yielded little success in the search for genes influencing intelligence. Robert Plomin is confident that QTLs responsible for the variation in IQ scores exist, but that more powerful tools of analysis will be required to detect them. Some researchers have expressed reluctance to investigate possible links between genes and intelligence, due to the controversy it can produce.

A 2005 literature review article on the links between race and intelligence in American Psychologist stated that no gene has been shown to be linked to intelligence, "so attempts to provide a compelling genetic link of race to intelligence are not feasible at this time". Two 2007 studies found that DTNBP1 and CHRM2 appear to influence intelligence depending on which allele of it a person carries. However, a study published in 2009 by Deary et al.. failed to find evidence of an association between these genes and general intelligence, stating "there is still almost no replicated evidence concerning the individual genes, which have variants that contribute to intelligence differences".

Health

Numerous explanations beside genetics have been proposed to account for the IQ gaps in the US. High rates of low birth-weight babies, lower rates of breastfeeding, and exposure to toxins are some factors. The Flynn effect is often cited as evidence that average IQ scores have changed greatly and rapidly, for reasons poorly understood, thus the IQ gap between races could change in the future or is changing, especially if the Flynn effect started earlier for Whites.

High levels of lead at an early age may affect intelligence; studies indicate that black and Hispanic children have measurably higher levels than white children. A 10 µg/dL increase in blood lead at 24 months of age is associated with a 5.8-point lower IQ later in life. In 1976 77.8% of all children had at least this much lead in their blood.

Exposure to lead is frequently attributed to housing conditions including lead based paint, which is no longer used but has accumulated in older buildings; people of lower economic means are more frequently exposed to lead from housing.

Quality of education

Some researchers have written that studies that find test performance gaps between races even after adjusting for education level, such as the analysis found in The Bell Curve, fail to adjust for the quality of education. Not all high school graduates or college graduates have received the same quality of education. A 2006 study reported that years of education is an inadequate measure of the educational experience among multicultural elders, and that adjusting for quality of education greatly reduced the overall effect of racial differences on the tests. A 2004 study reported that quality of education and cultural experience influence how older African Americans approach neuropsychological tasks and concluded that adjustment for these variables may improve specificity of neuropsychological measures. Yet another study reported that, although significant differences were observed between the ethnic groups when matched for years of education, equating for literacy level eliminated all performance differences between Black Americans and White Americans on both cancellation tasks which assess visual scanning (like reaction time tests, cancellation task tests are sometimes regarded as "culture free" tests of intelligence). Eric A. Hanushek and Steven G. Rivkin wrote in their 2006 book that unequal distributions of inexperienced teachers and of racial concentrations in schools can explain all of the increased achievement gap between grades 3 and 8. In recent years there have also been studies into the degrees in which many minorities, especially blacks, have internalized pathologies about their supposed lack of intelligence and the effects they have in their self-confidence, quality of learning and achievement. Additionally, Jensen's studies (Jensen, 1974b) show that 7% of black children of black professionals have mean IQs below that of white children from low-income families, yet this seems to have little to no detriment on the black children's success.

A 2004 study in South Africa found highly significant effects for both level and quality of education within the black African first language groups taking the Wechsler IQ tests. The scores of black African first language groups with advantaged education were comparable with the US standardization, whereas scores for black African first language participants with disadvantaged education were significantly lower than this. The study cautioned that faulty conclusions may be drawn about the effects of ethnicity and the potential for neuropsychological misdiagnosis.

Racial discrimination in education

Roslyn Arlin Mickelson writes that racial discrimination in education arises from actions of institutions or individual state actors, their attitudes and ideologies, or processes that systematically treat students from different racial/ethnic groups disparately or inequitably. Despite advancement in education reform efforts, to this day African American students continue to experience inequities within the educational system. Hala Elhoweris, Kagendo Mutua, Negmeldin Alsheikh and Pauline Holloway conducted a study of the effect of students' ethnicity on teachers' educational decision making. The results of this study indicated that the students' ethnicity did make a difference in the teachers' referral decisions for gifted and talented educational programs. Recently, a number of scholars have examined the issue of disproportionate representation of minority students in special education programs.

Teachers' perceptions of a student's cultural background may affect school achievement. African American students with African American cultural backgrounds, for example, have been found to benefit from culturally responsive teaching. In a 2003 study, researchers found that teachers perceived students with African American culture-related movement styles as lower in achievement, higher in aggression, and more likely to need special education services than students with standard movement styles irrespective of race or other academic indicators.

Ellis Cose writes that low expectations may have a negative impact on the achievement of minorities. He writes that black people did not need to read The Bell Curve to be aware of the low expectations held for them by the majority culture. He recalls examples of low expectations from his teachers in school who regarded his use of AAVE as "laziness" and teachers who did not feel it was important to purchase new text books because they did not expect the students to be able to read anything complex. He contrasts these low expectations with the high expectations philosophy of Xavier University where, using the ideas Whimbey articulated in his book Intelligence can be Taught teachers created a program called SOAR. SOAR raised the performance of black students and lead Xavier to become the university that sends the greatest number of black students to medical school in the US. The SOAR program produced gains equivalent to 120 points on an SAT test. Cose writes that "...we must treat people, whatever their color, as if they have unlimited intellectual capacity."

Structural equation models have been used to test for possible uncommon factors in the development of children belonging to different ethnic groups, which would include the results of racial discrimination. However, these tests have concluded that black, white, Hispanic and Asian children follow developmental processes which are "nearly identical".

Caste-like minorities

The book Inequality by Design: Cracking the Bell Curve Myth (1996) claims that it is not lower average intelligence that leads to the lower status of racial and ethnic minorities, it is instead their lower status that leads to their lower average intelligence test scores. To substantiate this claim, the book presents a table comparing social status or caste position with test scores and measures of school success in several countries around the world. The authors note, however, that the comparisons made in the table do not represent the results of all relevant findings, nor do they reflect the fact that the tests and procedures varied greatly from study to study. The comparison of Jews and Arabs, for example, is based on a news report that, in 1992, 26% of Jewish high school students passed their matriculation exam, as opposed to 15% of Arab students.

Other views

Jared Diamond's Guns, Germs and Steel argues that historical differences in economic and technological development for different geographic 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. Richard Nisbett argues in his 2004 The Geography of Thought that some of these regional differences shaped lasting cultural traits, such as the collectivism required by East Asian rice irrigation, compared with the individualism of ancient Greek herding, maritime mercantilism, and money crops wine and olive oil However, it has been suggested that these environmental differences may operate in part by selecting for higher levels of IQ.

Differing rates of economic growth have also been attributed to numerous factors other than racial IQ gaps such as local availability of resources, climate, and sociopolitical factors. See for example the Global Competitiveness Report, the Ease of Doing Business Index, and the Index of Economic Freedom or works by Kenneth Pomeranz, Eric Jones, Joel Mokyr, and Douglass C. North.

Debating the hereditarian position

A few of the notable proponents of the partly genetic hypothesis are Raymond B. Cattell, Arthur Jensen and Hans Eysenck.

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). Their article "Thirty Years of Research on Race Differences in Cognitive Ability" was published in the APA journal Psychology, Public Policy and Law showing evidence that they believe supports the hereditarian model. Rushton and Jensen (2005a) believe that the best explanation for the gap is that 50-80% of the group differences in average US IQ is genetic.

Other evidence, such as the Minnesota Transracial Adoption Study, certain racial admixture studies, behavior genetic modeling of group differences, "life-history" traits, and evolutionary explanations have also been proposed to indicate a genetic contribution to the IQ gaps and explain how these arose.

Outdated methodology

A 2006 paper by Professor Denny Borsboom argues that mainstream contemporary test analysis does not reflect substantial recent developments in the field and "bears an uncanny resemblance to the psychometric state of the art as it existed in the 1950s." It also claims that some of the most influential recent studies on group differences in intelligence, in order to show that the tests are unbiased, use outdated methodology; in particular the reliance on classical test theory rather than more sophisticated measurement models as found in item response theory. In response to criticism, proponents of the genetic hypothesis claim they use a standard for intelligence known as g. g is measured by performance on test items without the influence of language or math.

Test construction

While the existence of average IQ test score differences has been a matter of accepted fact for decades, a great deal of controversy exists among scholars over the question of whether these score differences reflect real differences in cognitive ability. Some claim that there is no evidence for test bias since IQ tests are equally good predictors of IQ-related factors (such as school performance) for US Blacks and Whites. The performance differences persist in tests and testing situations in which care has been taken to eliminate bias. It has also been suggested that IQ tests are formulated in such a way as to disadvantage minorities. Controlled studies have shown that test construction does not substantially contribute to the IQ gap. However, some psychometricians are not satisfied that the question of test bias is fully answered by these results.

The preponderance of evidence indicates that IQ tests measuring general intelligence are crossculturally valid. There is little or no evidence of population-specific cultural effects apart from the obvious example of language bias. For example, Robert Sternberg et al. found that the IQ of 12- to 15-year-old Kenyans predicted school grades at about the same level as they do in the West. IQ also predicted university performance equally well in African and non-African engineering students in South Africa in a 2004 study. Salgado et al. (2003) demonstrated the international generalizability of general mental ability across 10 member countries of the European Community and differences in a nation's culture, religion, language, socioeconomic level or employment legislation did not affect the predictive validity of IQ tests.

However, other studies have found evidence for bias. A 2005 study found some evidence that the WAIS-R is not culture-fair for Mexican Americans. Other recent studies have questioned the culture-fairness of IQ tests when used in South Africa.

Lack of direct evidence

Nisbett (2005) argues that many studies find results that do not support the genetic hypothesis. They include studies on IQ and skin color that reported that the average correlation between skin color and IQ is 0.1 (the average correlation between IQ and judged "Negroidness" of features is even lower); IQ and self-reported European ancestry; IQ and blood groups showing degree of European Ancestry; IQ among children in post WWII Germany born to black and white American soldiers; and IQ among mixed-race children born to either a black or a white mother. He argues that these are direct tests of the genetic hypothesis and of more value than indirect variables, such as skull size and reaction time. He argues that "There is not a shred of evidence in this literature, which draws on studies having a total of five very different designs, that the gap has a genetic basis." He argues further that many intervention and adoption studies also find results that do not support the genetic hypothesis. He also argues "that the Black-White IQ gap has lessened considerably in recent decades." Hunt and Carlson argue that Nisbett's interpretations are far too strong in light of problems with these studies that have been recognized for decades. Gottfredson writes that the studies Nisbett cites "actually lack the ability to rule out any hypothesis at all, genetic or not".

Dickens (2005) states that "Although the direct evidence on the role of environment is not definitive, it mostly suggests that genetic differences are not necessary to explain racial differences. Advocates of the hereditarian position have therefore turned to indirect evidence ... The indirect evidence on the role of genes in explaining the black-white gap does not tell us how much of the gap genes explain and may be of no value at all in deciding whether genes do play a role. Because the direct evidence on ancestry, adoption, and cross-fostering is most consistent with little or no role for genes, it is unlikely that the black-white gap has a large genetic component."

Fryer and Levitt (2006), with data from "the first large, nationally representative sample" of its kind, report finding only a very small racial difference when measuring mental function for children aged eight to twelve months, and that even these differences disappear when including a "limited set of controls". "On tests of intelligence, Blacks systematically score worse than Whites, whereas Asians frequently outperform Whites. Some have argued that genetic differences across races account for the gap. Using a newly available nationally representative data set that includes a test of mental function for children aged eight to twelve months, we find only minor racial differences in test outcomes (0.06 standard deviation units in the raw data) between Blacks and Whites that disappear with the inclusion of a limited set of controls. The only statistically significant racial difference is that Asian children score slightly worse than those of other races." They argue that their report poses "a substantial challenge to the simplest, most direct, and most often articulated genetic stories regarding racial differences in mental function". They conclude that "to the extent that there are any genetically-driven racial differences in intelligence, these gaps must either emerge after the age of one, or operate along dimensions not captured by this early test of mental cognition".

Utility of research

Theories of race and intelligence have been challenged on grounds of their utility. Critics want to know what purpose such research could serve and why it has been an intense area of focus for a few researchers. Some defend the research, saying it has egalitarian aims. IQ is, after all, a predictor of educational achievement and special needs. Accordingly, as a matter of public policy, resources can be better allocated by reducing the data to better understand the challenges; it is considered a pure science. Still others say that the true motivation for the research is the same as that of the eugenics movement and other forms of scientific racism. Even supporters of intelligence research have described such research as analogous to "working with dynamite" or "dangerous play" in sports.

Jensen and Rushton have justified their research in this area as being necessary to answer the question of how much white racism should be held responsible for ethnic groups' unequal performance in certain areas. They maintain that when racism is blamed for disparities which are the result of biological differences, the result is mutual resentment, and unjustified punishment of the more successful group. They state:

he view that one segment of the population is largely to blame for the problems of another segment can be even more harmful to racial harmony, by first producing demands for compensation and thereby inviting a backlash. Equating group disparities in success with racism on the part of the more successful group guarantees mutual resentment. As overt discrimination fades, still large racial disparities in success lead Blacks to conclude that White racism is not only pervasive but also insidious because it is so unobservable and "unconscious." Whites resent that nonfalsifiable accusation and the demands to compensate Blacks for harm they do not believe they caused.

Regarding whether research in this area is desirable, John C. Loehlin wrote in 1992, "Research on racial differences in intelligence is desirable if the research is appropriately motivated, honestly done, and adequately communicated." Defenders of the research suggest that both scientific curiosity and a desire to draw benefits from the research are appropriate motivations. Researchers such as Richard Lynn have suggested that conclusions from the research can help make political decisions, such as the type of educational opportunities and expectations of achievement policy makers should have for people of different races. Charles Murray, a political scientist of the American Enterprise Institute has used their conclusions to criticize social programs based on racial equality that fail, he claims, to recognize the realities of racial differences.

Source of funding

Vocal proponents of partially genetic explanations of race/IQ correlation, such as Rushton, Lynn, and Jensen, have been criticized for receiving funding from the Pioneer Fund, a group that has been reported as having had ties to German eugenicists working under the Nazi regime as well as to other US eugenicists of the early 20th century. The Southern Poverty Law Center considers the Pioneer Fund to be a hate group. Rushton is the current head of the Pioneer Fund and has spoken at conferences of the American Renaissance magazine, in which he has also published articles.

Proponents of genetic explanations of race-IQ correlation have in turn accused their critics of suppressing scientific debate in the name of political correctness. They claim harassment and interference with both their work and funding. The Pioneer Fund, whose stated purpose is "to advance the scientific study of heredity and human differences", makes "no grants to individuals but only to research institutions, mainly universities, mostly for specialized 'niche' projects, which have difficulty attracting funds from government sources or from larger foundations".

History of debate

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The idea that there are differences in the brain structures or sizes of different racial and ethnic groups was widely held and studied during the 19th and early 20th centuries. During this time period, research on race and intelligence was often used to claim that one race was superior to another, justifying the poor status and treatment of the "inferior" race.

Sir Francis Galton, a psychometrician and polymath (1822–1911), spurred interest in the study of mental abilities, particularly as they relate to heredity and eugenics. Galton claimed from his field observations in Africa that the African people were significantly below Anglo-Saxons' position in the normal frequency distribution of general mental ability; these claims continue to spark controversy in academia.

The scientific debate on the contribution of nature versus nurture to individual and group differences in intelligence can be traced back to at least the mid-19th century. Beginning in the 1930s, race difference research and hereditarianism—the belief that genetics are the primary cause of differences in intelligence among human groups—began to fall out of favor in psychology and anthropology after major internal debates. By 1961, the mainstream view was that there were no race differences in intelligence, or if there were, they were solely the result of environmental factors.

The most controversial and most publicized part of the 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 which could vary with biogeographic ancestry.

The 1970s debates

See also: Arthur Jensen

Publication in 1969 of psychologist Arthur Jensen's controversial article, "How Much Can We Boost IQ and School Achievement?" triggered the modern debate. In it, he wrote, "All we are left with are various lines of evidence, no one of which is definitive alone, but which, viewed together, make it a not unreasonable hypothesis that genetic factors are strongly implicated in the average negro-white intelligence difference. The preponderance of evidence is, in my opinion, less consistent with a strictly environmental hypothesis than with a genetic hypothesis, which, of course, does not exclude the influence of environment or its interaction with genetic factors." Philosopher Peter Singer wrote that Jensen's article was widely reported in the popular press "as an attempt to defend racism on scientific grounds".

An advocate of population control, physicist William Shockley focused on questions of race, intelligence, and eugenics and published several controversial papers arguing that intelligence is primarily hereditary. He postulated that the higher reproduction rate of those with lower intelligence has a dysgenic effect on society and proposed that individuals with IQs below 100 be paid to undergo voluntary sterilization. Biologists and geneticists criticized his theories, comparing them to rationale used by the Nazis in carrying out their genocidal policies. Criticism of Shockley's racial ideas appeared in scientific journals and was reflected in the popular press.

Arguing that environmental factors could explain the black-white IQ gap, population geneticist Luigi Luca Cavalli-Sforza debated Jensen and Shockley.

The 1990s Bell Curve debates

See also: The Bell Curve

Discussion centers on whether group differences in average IQ are purely social, economic, and cultural or are hard-wired in genetics. The American Anthropological Association has declared that "differentiating species into biologically defined 'races' has proven meaningless and unscientific as a way of explaining variation", while the American Psychological Association has stated that the causes of inter-group IQ differences are unknown.

Academics such as Michael Levin and J. Philippe Rushton differ from the American Anthropological Association in their claims that IQ score differences are traceable to genetics. Stephen Jay Gould, Richard Levin, Richard Lewontin and Joseph L. Graves contend that the proponents of the genetics explanation are wrong.

The book The Bell Curve by psychologist Richard Herrnstein and American Enterprise Institute political scientist Charles Murray wrote: "The debate about whether and how much genes and environment have to do with ethnic differences remains unresolved. The universality of the contrast in nonverbal and verbal skills between East Asians and European whites suggests, without quite proving, genetic roots." Herrnstein and Murray said intelligence is a better predictor of many factors including financial income, job performance, unwed pregnancy, and crime than parents' socioeconomic status or education level.

The Bell Curve attracted attention, both critical of and in defense of the book. Critics called it scientific racism. Several books were written in response, including The Bell Curve Debate and The Mismeasure of Man (second edition), and scholarly associations released statements of opinion.

The American Psychological Association's Board of Scientific Affairs in 1995 established a task force which produced a report, "Intelligence: Knowns and Unknowns" The psychology association report authors wrote that IQ scores have high predictive validity for individual differences in school achievement, for adult occupational status, even when variables such as education and family background have been statistically controlled, and they said individual differences in intelligence are substantially influenced by genetics (75% in adults). Contrary to Herrnstein and Murray's findings, they wrote that prolonged malnutrition during childhood does have long-term intellectual effects. The APA report confirmed the existence of racial IQ differences, while remaining agnostic about their underlying causes:

The differential between the mean intelligence test scores of Blacks and Whites (about one standard deviation, although it may be diminishing) does not result from any obvious biases in test construction and administration, nor does it simply reflect differences in socio-economic status. Explanations based on factors of caste and culture may be appropriate, but so far have little direct empirical support. There is certainly no such support for a genetic interpretation. At present, no one knows what causes this differential.

The APA report concluded with a call for more reflection in debates on intelligence and for a "shared and sustained effort" for more research to answer the many unanswered questions that remain.

Eleven critical responses appeared in the January 1997 issue of American Psychologist, suggesting ways in which the APA report could have been improved. The responses by Richard Lynn and J. Philippe Rushton disputed the task force's conclusion that there is no direct evidence for a genetic interpretation of the IQ difference between blacks and whites.

On December 13, 1994, psychologist Linda Gottfredson and 51 specialists in intelligence and related fields asserted on the opinion page of the Wall Street Journal that IQ bell curves differ across racial and ethnic groups for varying reasons. They maintained that, "Most experts believe that environment is important in pushing the bell curves apart, but that genetics could be involved too."

In 1994, the American Anthropological Association declared itself "deeply concerned by recent public discussions which imply that intelligence is biologically determined by race. Repeatedly challenged by scientists, nevertheless these ideas continue to be advanced. Such discussions distract public and scholarly attention from and diminish support for the collective challenge to ensure equal opportunities for all people, regardless of ethnicity or phenotypic variation".

In August 1995, at the National Bureau of Economic Research, economist Sanders Korenman and Harvard University sociologist Christopher Winship claimed to have found certain errors in Murray and Herrnstein's methodology. Korenman and Winship concluded: "... there is evidence of substantial bias due to measurement error in their estimates of the effects of parents' socioeconomic status. In addition, Herrnstein and Murray's measure of parental socioeconomic status (SES) fails to capture the effects of important elements of family background (such as single-parent family structure at age 14). As a result, their analysis gives an exaggerated impression of the importance of IQ relative to parents' SES, and relative to family background more generally. Estimates based on a variety of methods, including analyses of siblings, suggest that parental family background is at least as important, and may be more important than IQ in determining socioeconomic success in adulthood."

Policy implications

See also: Intelligence and public policy

Public policy implications of IQ and race research are one of the greatest sources of controversy surrounding this issue. Regardless of the source of the IQ gap, most educators agree that it must be addressed; they often advocate more equitable funding for education. An achievement gap refers to the observed disparity in the performance of groups of students, primarily in those defined by race or ethnicity, in educational measures such as standardized test scores, grade point average, dropout rates and course enrollment and completion rates.

Some proponents of a genetic interpretation of the IQ gap, such as Rushton and Jensen (2005a) and Gottfredson (2005b), have sometimes argued that their interpretation does not in itself demand any particular policy response: while a conservative/libertarian commentator may feel the results justify, for example, reductions in affirmative action, a liberal commentator may argue from a Rawlsian point of view (that genetic advantages are undeserved and unjust) for substantial affirmative action. Since all races have representatives at all levels of the IQ curve, this means any policy based on low IQ affects members of all races.

In the book Practical Ethics, philosopher Peter Singer wrote that:

Let us suppose that the genetic hypothesis turns out to be correct... I believe that the implications of this supposition are less drastic than they are often supposed to be... First, the genetic hypothesis does not imply that we should reduce our efforts to overcome other causes of inequality between people... Perhaps we should put special efforts into helping those who start from a position of disadvantage, so that we end with a more egalitarian result. Second, the fact that the average IQ of one racial group is a few points higher than that of another does not allow anyone to say that all members of the higher IQ group have higher IQs... The point is that these figures are averages and say nothing about individuals... The third reason... is simply that, as we saw earlier, the principle of equality is not based on any actual equality that all people share. I have argued that the only defensible basis for the principle of equality is equal consideration of interests... Equal status does not depend on intelligence. Racists who maintain the contrary are in peril of being forced to kneel before the next genius they encounter.

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).

See also

• Height and intelligence
• Hominid intelligence
• Neuroscience and intelligence
• Sex and intelligence

Related publications:

• The Bell Curve (1994)
• Intelligence: Knowns and Unknowns (1996)
• IQ and Global Inequality (2006)
• The Mismeasure of Man (1981)
• Mainstream Science on Intelligence (1994; 1997)
• Race Differences in Intelligence (2006)
• Survey of Expert Opinion on Intelligence and Aptitude Testing (1987)

Other medical:

• Ancestry and health
• Population groups in biomedicine

Notes

1. ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1038/457786a, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1038/457786a instead.
2. ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1038/457788a, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1038/457788a instead.
3. The Bell Curve Wars. Race, Intelligence, and the Future of America
4. Race Differences in Intelligence
5. Attention: This template ({{cite jstor}}) is deprecated. To cite the publication identified by jstor:284632, please use {{cite journal}} with |jstor=284632 instead.
6. ^ Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1037/0003-066X.60.1.46, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1037/0003-066X.60.1.46 instead. Cite error: The named reference "Intelligence, Race, and Genetics" was defined multiple times with different content (see the help page).
7. ^ Neisser, U., G. Boodoo, T. J. Bouchard, A. W. Boykin, N. Brody, S. J. Ceci, D. F. Halpern, J. C. Loehlin, R. Perloff, R. J. Sternberg and S. Urbina. 1996. "Intelligence: knowns and unknowns." American Psychologist 51:77-101.
8. ^ Nisbett 2009 Intelligence and how to get it: Why schools and cultures count
9. Flynn 2007 What Is Intelligence?: Beyond the Flynn Effect
10. Flynn 1980 Race, IQ, and Jensen
11. Lichtenberger, Elizabeth O.; Kaufman, Alan S (2002). Assessing adolescent and adult intelligence. Boston: Allyn and Bacon. p. 23. ISBN 020530527x. {{cite book}}: Check |isbn= value: invalid character (help)CS1 maint: multiple names: authors list (link)
12. Dolan, C. V. (2000). Investigating Spearman's hypothesis by means of multi-group confirmatory factor analysis. Multivariate Behavioral Research, 35, 21-50.
13. Dolan, C. V., & Hamaker, E. L. (2001). Investigating black-white differences in psychometric IQ: Multi-group confirmatory factor analyses of WISC-R and K-ABC and a critique of the method of correlated vectors. In F. Columbus (Ed.), Advances in psychology research (Vol. 6, pp. 30-59). Huntington, NY: Nova Science.
14. Lubke, G. H., Dolan, C. V., Kelderman, H., & Mellenbergh, G. J. (2003). On the relationship between sources of within- and between-group differences and measurement invariance in the common factor model. Intelligence, 31, 543–566.
15. Jensen 1998
16. ^ James R. Flynn, The Black-White IQ Gap
17. Loehlin, J. C., Lindzey, G., & Spuhler, J. N. (1975). Race differences in intelligence. San Francisco, CA: W.H. Freeman.
18. Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:doi:10.1016/j.intell.2006.07.004, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=doi:10.1016/j.intell.2006.07.004 instead.
19. Arthur Jensen (1998). The g Factor.
20. Roth et al. 2001
21. Berry, J. W. (1966). Temne and Eskimo perceptual skills. International Journal of Psychology, 1, 207-222.
22. MacArthur, R. S. (1968). Some differential abilities of northern Canadian native youth. International Journal of Psychology, 3, 43-51.
23. Roth, P. L., Bevier, C. A., Bobko, P., Switzer, F. S. III, & Tyler, P. (2001). Ethnic group differences in cognitive ability in employment and educational settings: A meta-analysis. Personnel Psychology, 54, 297-330.
24. ^ Hunt, Earl & Carlson, Jerry. Considerations Relating to the Study of Group Differences in Intelligence. Perspectives on Psychological Science 2 (2), 194-213.
25. Backman, M.E. (1972) Patterns of mental abilities: ethnic, socioeconomic and sex differences. American Educational Research Journal, 9,1-12.
26. ^ Lynn, Richard (2003). The Intelligence of American Jews. Elsevier Ltd. doi:10.1016/S0191-8869(03)00079-5.
27. Cochran, Gregory & Hardy, Jason & Harpending, Henry. Natural History of Ashkenazi Intelligence. Journal of Biosocial Science, Vol. 38, No. 05. (2005), pp. 659-693.
28. Carretta, T. R., & Ree, M. J. (1995). Near identity of cognitive structure in sex and ethnic groups. Personality and Individual Differences, 19, 149-155.
29. IQ and the Wealth of Nations, Race Differences in Intelligence, and IQ and Global Inequality
30. Satoshi Kanazawa, Temperature and evolutionary novelty as forces behind the evolution of general intelligence
31. Steven M. Shatz, IQ and fertility: A cross-national study
32. The decline of the world's IQ
33. ^ Relevance of education and intelligence at the national level for the economic welfare of people
34. Herrnstein and Murray 1994; Lynn 1991a; Lynn 2006
35. Rushton, J. P. (2006). "Lynn Richard, Race Differences in Intelligence: An Evolutionary Analysis, Washington Summit Books, Augusta, GA (2005) ISBN 1-59368-020-1, 318 pages., US$34.95". Personality and Individual Differences. 40 (4): 853–855. doi:10.1016/j.paid.2005.10.004.
36. Lynn, R. and Vanhanen, T. (2002). IQ and the wealth of nations. Westport, CT: Praeger. ISBN 0-275-97510-X
37. Rindermann, H. (2006). What do international student assessments measure?. Psychologische Rundschau, 57, 69–86.
38. Relevance of education and intelligence for the political development of nations: Democracy, rule of law and political liberty
39. National differences in intelligence and educational attainment
40. Wicherts, J.M. (December 15, 2006). The dark past, obscure present, and bright future of African IQ. 7th Annual Conference of the International Society for Intelligence Research (ISIR), San Francisco, CA, US.
41. Cohen, Mark N. (2005). "Race and IQ Again: A Review of Race: The Reality of Human Differences by Vincent Sarich and Frank Miele". Evolutionary Psychology. Volume 3, pp. 255-262.
42. ^ Neisser et al. 1996
43. ^ Considerations Relating to the Study of Group Differences in Intelligence. Blackwell Synergy - Perspect on Psych Science, Volume 2 Issue 2 Page 194-213, June 2007 (Article Abstract)
44. Reviewed in Neisser et al. (1996). Data from the NLSY as reported in figure adapted from Herrnstein and Murray (1994), p. 288.
45. Aronson, Wilson, & Akert, 2005
46. Flynn 1987, Flynn 1987b, Flynn 1999, Flynn 1999b
47. Colom et al. 2005
48. Nichols, R. C. (1987). Interchange: Nichols replies to Flynn. In S. Modgil & C. Modgil (Eds.), Arthur Jensen: Consensus and controversy (pp. 233–234). New York, NY: Falmer.
49. Flynn 1999
50. Flynn (2007)
51. James Robert Flynn (2007) What is Intelligence?: Beyond the Flynn Effect. Cambridge University Press: Cambridge
52. Wicherts et al. (2004) found that measurement bias contributes to the Flynn effect. They wrote that "the gains cannot be explained solely by increases at the level of the latent variables (common factors), which IQ tests purport to measure." and "It appears therefore that the nature of the Flynn effect is qualitatively different from the nature of differences in the United States" (p. 531).
53. How Heritability Misleads about Race
54. R. J. Sternberg (2000) Handbook of Intelligence. Cambridge: Cambridge University Press
55. David J. Bartholomew (2004) Measuring Intelligence: Facts and Fallacies. Cambridge: Cambridge University Press
56. Ian J. Deary. (2001) Intelligence: A Very Short Introduction. Oxford: Oxford University Press
57. Gottfredson, L. S. (Ed.). (1997). Intelligence and social policy . Intelligence, 24(1).
58. Gottfredson, L. S. (1997). Mainstream science on intelligence: An editorial with 52 signatories, history, and bibliography. Intelligence, 24(1), 13-23.
59. Robert Plomin, John C. DeFries, Gerald E. McClearn, and Peter McGuffin (2000) Behavioral Genetics. Worth Publishers; Fourth Edition edition
60. Brody, N. (1992). Intelligence (2nd ed.). San Diego, CA: Academic Press.
61. Snyderman, M., & Rothman, S. (1988). The IQ controversy, the media and public policy. New Brunswick, NJ: Transaction Press.
62. "Genetic foundations of human intelligence", Ian J. Deary, W. Johnson, L. M. Houlihan Hum Genet (2009) 126:215–232 doi:10.1007/s00439-009-0655-4
63. Jensen (1998) The g Factor
64. Flynn (1980) and Flynn (1999)
65. Lewontin, R. (1970) "Race and Intelligence". Science and Public Affairs March, pp. 2-8
66. Layzer, David. (1974) "Heritability analyses of IQ scores: Science or numerology?" Science 183 pp. 1259-66
67. Schizophrenia and Bipolar Disorder Share Genetic Roots
68. Jianxin S, et al. Common variants on chromosome 6p22.1 are associated with schizophrenia. July 1, 2009, Nature
69. Stefansson H, et al. Common variants conferring risk of schizophrenia. July 1, 2009, Nature
70. Purcell SM, et al. Common polygenic variation contributes to risk of schizophrenia that overlaps with bipolar disorder. July 1, 2009, Nature
71. "Race differences in intelligence" Richard Lynn, 2006
72. (Stringer, 1989, Cavalli-Sforza, 2000)
73. http://www.ssc.uwo.ca/psychology/faculty/rushtonpdfs/2004%20Human%20Evolution.pdf
74. Waldman, Weinberg, & Scarr, 1994
75. Weinberg, Scarr, & Waldman, 1992
76. Flynn 1980
77. Tizard, Barbara; Cooperman, Oliver; Joseph, Anne; Tizard, Jack. (1972). Environmental effects on language development: A study of young children in long-stay residential nurseries.
78. Plomin, R; Kennedy, J; Craig, I (2005). "The quest for quantitative trait loci associated with intelligence". Intelligence. 34: 513. doi:10.1016/j.intell.2006.01.001.
79. Antonio Regalado. Scientist's Study Of Brain Genes Sparks a Backlash. The Wall Street Journal. June 16, 2006.
80. Janneke R Zinkstok, Odette de Wilde, Therese AMJ van Amelsvoort, Michael W Tanck, Frank Baas and Don H Linszen (2007). "Association between the DTNBP1 gene and intelligence: a case-control study in young patients with schizophrenia and related disorders and unaffected siblings". Behavioral and Brain Functions 3:19 doi:10.1186/1744-9081-3-19
81. Dick DM, Aliev F, Kramer J, Wang JC, Hinrichs A, Bertelsen S, Kuperman S, Schuckit M, Nurnberger J Jr, Edenberg HJ, Porjesz B, Begleiter H, Hesselbrock V, Goate A, Bierut L (2007). “Association of CHRM2 with IQ: converging evidence for a gene influencing intelligence.” Behavioral Genetics 37(2):265-72
82. Deary (2009). "Genetic foundations of human intelligence". doi:0.1007/s00439-009-0655-4. {{cite journal}}: Check |doi= value (help); Cite journal requires |journal= (help); Unknown parameter |doi_brokendate= ignored (|doi-broken-date= suggested) (help)
83. Joel Wiesen, "An Annotated List of Many Possible Reasons for the Black-White Mean Score Differences Seen With Many Cognitive Ability Tests: Notes to File," Applied Personnel Research, March 18, 2005.
84. Low-Level Lead Exposure, Intelligence and Academic Achievement: A Long-term Follow-up Study David C. Bellinger PhD, MSc1, Karen M. Stiles PhD, MN1, and Herbert L. Needleman MD1. Pediatrics Vol. 90 No. 6 December 1992, pp. 855-861
85. Blood Lead Levels — United States, 1999–2002 CDC.
86. Mfume Calls Lead Paint Poisoning "The Silent Epidemic" NAACP Press Release 17 July 2001
87. Reading level attenuates differences in neuropsychological test performance between African American and White elders Jennifer J. Manly, Diane M. Jacobs, Pegah Touradji, Scott A. Small and Yaakov Stern
88. Acculturation, Reading Level, and Neuropsychological Test Performance Among African American Elders Jennifer J. Manly, Desiree A. Byrd, Pegah Touradji, Yaakov Stern‌
89. Cancellation test performance in African American, Hispanic, and White elderly Desiree A. Byrd, Pegah Touradji, Ming-Xin Tang and Jennifer J. Manly
90. School Quality and the Black-White Achievement Gap Eric A. Hanushek and Steven G. Rivkin 2006
91. Race and Intelligence: Separating Science from Myth By Jefferson M. Fish
92. Race, Social Class, and Individual Differences in I.Q. By Sandra Scarr
93. Cross-cultural Effects on IQ Test Performance: A Review and Preliminary Normative Indications on WAIS-III Test Performance Journal of Clinical and Experimental Neuropsychology Volume 26, Number 7 / October 2004
94. When Are Racial Disparities in Education the Result of Racial Discrimination? A Social Science Perspective by Roslyn Arlin Mickelson University of North Carolina at Charlotte
95. Effect of Children's Ethnicity on Teachers' Referral and Recommendation Decisions in Gifted and Talented Programs Journal article by Negmeldin Alsheikh, Hala Elhoweris, Pauline Holloway, Kagendo Mutua; Remedial and Special Education, Vol. 26, 2005
96. (Salend, Garrick Duhaney, & Montgomery, 2002; Townsend, 2002)
97. Racial Inequity in Special Education. Losen, Daniel J., Ed.; Orfield, Gary, Ed. Harvard Education Publishing Group.
98. (Gay, 2000; Irvine & Armento, 2001; Ladson-Billings, 1994, 2001)
99. The Effects of African American Movement Styles on Teachers' Perceptions and Reactions Journal article by Scott T. Bridgest, Audrey Davis Mccray, La Vonne I. Neal, Gwendolyn Webb-Johnson; Journal of Special Education, Vol. 37, 2003
100. Color-Blind Ellis Cose. Page 50
101. Rowe, David C., Vazsonyi, Alexander T. and Flannery, Daniel J. [0]=2115 No More Than Skin Deep: Ethnic and Racial Similarity in Developmental Process. Psychological Review 101,3 (July 1994): 396-413
102. Rowe, David C. and Hobart H. Cleveland. Academic achievement in Blacks and Whites: Are the developmental processes similar? Intelligence Volume 23, Issue 3, November-December 1996, Pages 205-228.
103. ^ Inequality by Design: Cracking the Bell Curve Myth by Claude S. Fischer, Michael Hout, Martín Sánchez Jankowski, Samuel R. Lucas, Ann Swidler, and Kim Vos. Page 192. Cite error: The named reference "bell myth" was defined multiple times with different content (see the help page).
104. (pp. 34-35).
105. This theory is discussed by Jensen (1998b) (pp. 435-437), Lynn (1991b) and Rushton (2000) in general and by both Wade (2006) and Steve Sailer with respect to Guns, Germs, and Steel. See Race and intelligence (Explanations)#Rushton's application of r-K theory. .. Voight et al. (2006) state generally that "a number of recent studies have detected more signals of adaptation in non-African populations than in Africans, and some of those studies have conjectured that non-Africans might have experienced greater pressures to adapt to new environments than Africans have" (Kayser et al. 2003, Akey et al. 2004, Storz et al. 2004, Stajich and Hahn 2005, Carlson et al. 2005).
106. Pomeranz, Kenneth (2001). The Great Divergence. Princeton, NJ: Princeton University Press.
107. Jones, Eric (1997). The European Miracle. Cambridge: Cambridge University Press.
108. Mokyr, Joel (1992). The Lever of Riches. Oxford: Oxford University Press.
109. North, Douglass (1976). The Rise of the Western World. Cambridge: Cambridge University Press.
110. http://psychology.uwo.ca/faculty/rushtonpdfs/PPPL1.pdf Thirty Years of Research on Race Differences in Cognitive Ability
111. http://www.innovations-report.de/html/berichte/studien/bericht-43536.html Black-White-East Asian IQ differences at least 50% genetic, major law review journal concludes
112. Rushton and Jensen (2005a), cited in "Black-White-East Asian IQ differences at least 50% genetic, scientists conclude in major law journal", and Murray (2005)
113. Reviewed by Rushton and Jensen (2005).
114. The attack of the psychometricians. Denny Borsboom. Psychometrika Vol. 71, No. 3, 425–440. September 2006.
115. ^ Neisser, U., Boodoo, G., Bouchard, T. J. Jr., Boykin, A. W., Brody, N., Ceci, S. J. et al. (1996). Intelligence: Knowns and unknowns. American Psychologist, 51, 77–101.
116. Dolan, C. V. (1997). A note on Schönemann's refutation of Spearman's hypothesis. Multivariate Behavioral Research, 32, 319–325.
117. Dolan, C. V. (2000). Investigating Spearman's hypothesis by means of multi-group confirmatory factor analysis. Multivariate Behavioral Research, 35, 21–50.
118. Dolan, C. V., & Hamaker, E. L. (2001). Investigating Black-White differences in psychometric IQ: Multi-group confirmatory factor analyses of WISC-R and K-ABC and a critique of the method of correlated vectors. In F. Columbus (Ed.), Advances in psychology research (Vol. 6, pp. 30–59). Huntington, NY: Nova Science.
119. http://www.charlesdarwinresearch.org/PRSL2007.pdf
120. Sternberg, R. J., Nokes, C., Geissler, P. W., Prince, R., Okatcha, F., Bundy, D. A. & Grigorenko, E. L. 2001 The relationship between academic and practical intelligence: a case study in Kenya. Intelligence 29, 401–418.
121. Construct validity of Raven’s Advanced Progressive Matrices for African and non-African engineering students in South Africa.
122. Salgado, J. F., Anderson, N., Moscoso, S., Bertua, C. & Fruyt, F. D. 2003 International validity generalization of GMA and cognitive abilities: a European community meta-analysis. Pers. Psychol. 56, 573–605.
123. Culture-Fair Cognitive Ability Assessment Steven P. Verney Assessment, Vol. 12, No. 3, 303-319 (2005)
124. Cross-cultural effects on IQ test performance: a review and preliminary normative indications on WAIS-III test performance. Shuttleworth-Edwards AB, Kemp RD, Rust AL, Muirhead JG, Hartman NP, Radloff SE. J Clin Exp Neuropsychol. 2004 Oct;26(7):903-20.
125. Case for Non-Biased Intelligence Testing Against Black Africans Has Not Been Made: A Comment on Rushton, Skuy, and Bons (2004) 1*, Leah K. Hamilton1, Betty R. Onyura1 and Andrew S. Winston International Journal of Selection and Assessment Volume 14 Issue 3 Page 278 - September 2006
126. Heredity, Evironment, and Race differences in IQ. A Commentary on Rushton and Jensen (2005) Richard E. Nisbett, Psychology, Public Policy, and Law: June 2005 Vol. 11, No. 2, 302-310
127. Loehlin, J.C., Lindzey, G., & Spuhler, J. (1975). Racial Differences in Intelligence. San Francisco: Freeman.
128. http://www.udel.edu/educ/gottfredson/reprints/2007doublestandards.pdf
129. Genetic Differences and School Readiness Dickens, William T. The Future of Children - Volume 15, Number 1, Spring 2005, pp. 55-69
130. Roland G. Fryer Jr. and Steven D. Levitt, "Understanding the Black-White Test Score Gap in the First Two Years of School," The Review of Economics and Statistics 86, no. 2 (2004). Testing for Racial Differences in the Mental Ability of Young Children
131. ^ e.g., Sternberg, 2003, pp. 386–387
132. Hunt & Carlson, in press
133. Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi:10.1037/1076-8971.11.2.235, please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with |doi=10.1037/1076-8971.11.2.235 instead.
134. Southern Poverty Law Center Into the Mainstream; An array of right-wing foundations and think tanks support efforts to make bigoted and discredited ideas respectable. Retrieved April 15, 2008.
135. The American Breed: Nazi Eugenics and the Origins of the Pioneer Fund Retrieved Oct 27, 2009.
136. http://www.splcenter.org/intel/intelreport/article.jsp?pid=214#27
137. The Pioneer Fund, Inc.
138. Broca 1873; Bean 1906; Mall 1909; Morton 1839; Pearl 1934; Vint 1934
139. Social Darwinism, Scientific Racism, and the Metaphysics of Race Rutledge M. Dennis The Journal of Negro Education, Vol. 64, No. 3, Myths and Realities: African Americans and the Measurement of Human Abilities (Summer, 1995), pp. 243–252
140. Eugenics: America's Darkest Days
141. Francis Galton: British Psychologist
142. Degler 1992; Loehlin et al. 1975
143. According to historian of psychology Graham Richards there was widespread critical debate within psychology about the conceptual underpinnings of this early race difference research (Richards 1997). These include Estabrooks' (1928) two papers on the limitations of methodology used in the research; Dearborn and Long's (1934) overview of the criticisms by several psychologists (Garth, Thompson, Peterson, Pinter, Herskovits, Daniel, Price, Wilkerson, Freeman, Rosenthal and C.E. Smith) in a collection they edited and Klineburg, who wrote three major critiques, one in 1928, and two in 1935. Richards also notes that with over 1000 publications within psychology during the interwar years there had been a large internal debate. Towards the end of the time period almost all those publishing, including most of those who began with a pro-race differences stance, were firmly arguing against race differences research. Richards regards the scientific controversy to be dead at this point, although he also suggests reasons for its re-emergence in the late nineteen sixties.
144. Lynn 2001 pp. 67–69
145. Harvard Educational Review 39: 1-123
146. Practical Ethics 2nd edition by Peter Singer 1999 Princeton University Press ISBN 978-0521439718
147. William Shockley, Part 3 of 3
148. William Shockley - MSN Encarta
149. Shockley, William (1992). Shockley on Eugenics and Race: The Application of Science to the Solution of Human Problems. Washington, D.C.: Scott-Townsend Publishers. ISBN 978-1878465030.
150. A Genetic and Cultural Odyssey: The Life and Work of L. Luca Cavalli-Sforza by Linda Stone, pages 76, 168 ISBN 0231133960.
151. AAA statement on race and intelligence
152. Gould, Stephen Jay (1996). The Mismeasure of Man. Sagebrush Education Resources. ISBN 0613181301.
153. Lewontin, Richard (2001). It Ain't Necessarily So: The Dream of the Human Genome and Other Illusions. New York review of Books. ISBN 0940322951.
154. What a tangled web he weaves: Race, reproductive strategies and Rushton's life history theory by Joseph L Graves
155. American Psychological Association findings on predictive value of intelligence tests
156. Neisser, U. (1997). "Never a Dull Moment". American Psychologist 52: 79-81.
157. Gottfredson, Linda (December 13, 1994) "Mainstream Science on Intelligence". Wall Street Journal, p A18.
158. Mainstream science on intelligence
159. AAA Statement on "Race" and Intelligence
160. http://ssrn.com/abstract=225294 Korenman, Sanders and Winship, Christopher, "A Reanalysis of The Bell Curve" (August 1995). NBER Working Paper Series, Vol. w5230, 1995.
161. Achieving Equitable Education in Calhoun County
162. Educational Studies: A Journal of the American Educational Studies Association
163. For example, the policy recommendations of The Bell Curve were denounced by many. 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)" Two year later the 1996 U.S. welfare reform substantially cut these programs. In a discussion of the future political outcomes of an intellectually stratified society, they stated that they: "fear that a new kind of conservatism is becoming the dominant ideology of the affluent—not in the social tradition of an Edmund Burke or in the economic tradition of an Adam Smith but 'conservatism' along Latin American lines, where to be conservative has often meant doing whatever is necessary to preserve the mansions on the hills from the menace of the slums below. (p. 518)"Moreover, they fear that an increasing welfare will create a 'custodial state': 'a high-tech and more lavish version of the Indian reservation of some substantial minority of the nation's population. They also predict increasing totalitarianism: It is difficult to imagine the United States preserving its heritage of individualism, equal rights before the law, free people running their own lives, once it is accepted that a significant part of the population must be made permanent wards of the states. (p. 526)"
164. Gottfredson 2005b

References

• Akey, J. M., Eberle, M. A., Rieder, M. J., Carlson, C. S., Shriver, M. D., Nickerson, D. A. and Kruglyak, L. (2004). "Population History and Natural Selection Shape Patterns of Genetic Variation in 132 Genes". PLoS Biology. 2 (10): e286. doi:10.1371/journal.pbio.0020286. PMC 515367. PMID 15361935.{{cite journal}}: CS1 maint: multiple names: authors list (link) CS1 maint: unflagged free DOI (link)
• Bean, R. B. (1906). "Some Racial Peculiarities of the Negro Brain". American Journal of Anatomy. 5: 353–432. doi:10.1002/aja.1000050402.
• Berry, J. W. (1966). "Temne and Eskimo Perceptual Skills". International Journal of Psychology. 1: 207–222. doi:10.1080/00207596608247156.
• Broca, P. (1873). "Sur Les Crânes De La Caverne De 'Homme Mort (Loere)". Revue d’Anthropologie. 2: 1–53.
• Brody, N. (1992). Intelligence. San Diego, CA: Academic.
• Carlson CS, Thomas DJ, Eberle MA, Swanson JE, Livingston RJ, et al. (2005). Genomic regions exhibiting positive selection identified from dense genotype data. Genome Res 15: 1553–1565. PMID 16251465
• Carretta, T. R. and Ree, M. J. (1995). "Near Identity of Cognitive Structure in Sex and Ethnic Groups". Personality and Individual Differences. 19 (2): 149–155. doi:10.1016/0191-8869(95)00031-Z. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
• Chan, J. and Lynn, R. (1989). "The Intelligence of Six-Year-Olds in Hong Kong". Journal of Biosocial Science. 21 (4): 461–464. doi:10.1017/S0021932000018198. PMID 2808473. {{cite journal}}: Cite has empty unknown parameter: |month= (help)CS1 maint: multiple names: authors list (link)
• Cochran, G., Hardy, J., and Harpending, H. (2005). "Natural History of Ashkenazi Intelligence" (PDF). Journal of Biosocial Science. 38 (5): 659. doi:10.1017/S0021932005027069. PMID 16867211.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Colom, R., Lluis-Font, J.M., and Andrés-Pueyo, A. (2005). "The generational intelligence gains are caused by decreasing variance in the lower half of the distribution: Supporting evidence for the nutrition hypothesis". Intelligence. 33: 83–91. doi:10.1016/j.intell.2004.07.010.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Degler, C. N. (1992). In Search of Human Nature:The Decline and Revival of Darwinism in American Social Thought. New York: Oxford University Press. ISBN 0-415-28659-X.
• Dickens, W. T. (2005). "Genetic Differences and School Readiness" (PDF). Future of Children. 15 (1): 55–69. PMID 2005-04825-005. {{cite journal}}: Check |pmid= value (help); Unknown parameter |month= ignored (help)
• Dickens, W.T., and J.R. Flynn (In press). "Black Americans reduce the racial IQ gap: Evidence from standardized samples" (PDF). Psychological Science. {{cite journal}}: Check date values in: |year= (help)CS1 maint: multiple names: authors list (link) CS1 maint: year (link)
• Dolan, C. V. (1997). "A Note on Schönemann's Refutation of Spearman's Hypothesis". Multivariate Behavioral Research. 32: 319–325. doi:10.1207/s15327906mbr3203_4.
• Dolan, C. V. (2000). "Investigating Spearman's Hypothesis by Means of Multi-Group Confirmatory Factor Analysis". Multivariate Behavioral Research. 35: 21–50. doi:10.1207/S15327906MBR3501_2.
• Dolan, C. V. and Hamaker, E. L. (2001). "Investigating Black-White Differences in Psychometric IQ: Multi-Group Confirmatory Factor Analyses of the WISC-R and K-Abc, and a Critique of the Method of Correlated Vectors". In F. Columbus (ed.). Advances in Psychological Research (PDF). Huntington, NY: Nova Science Publishers, Inc. ISBN 1-56072-897-3. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)CS1 maint: multiple names: authors list (link)
• Espanshade, T. J., Chung, C. Y. (2005). "The Opportunity Cost of Admission Preferences at Elite Universities" (PDF). Social Science Quarterly. 86 (2): 293–305. doi:10.1111/j.0038-4941.2005.00303.x. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
• Flynn, J. R. (1980). Race, IQ and Jensen. London: Routledge & Kegan Paul. ISBN 0-7100-0651-9. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
• Flynn, J. R. (1987). "Massive IQ Gains in 14 Nations: What IQ Tests Really Measure". Psychological Bulletin. 101: 171–191. doi:10.1037/0033-2909.101.2.171.
• Flynn, J. R. (1987b). Race and IQ: Jensen's case refuted. In S. Modgil & C. Modgil (Eds.), Arthur Jensen: Consensus and controversy (pp. 221–232). Lewes, England: Falmer Press.
• Flynn, J. R. (1999). "Searching for Justice: The Discovery of IQ Gains over Time". American Psychologist. 54: 5–20. doi:10.1037/0003-066X.54.1.5.
• Flynn, J. R. (1999b). Reply to Rushton: A gang of gs overpowers factor analysis. Personality and Individual Differences, 26, 391–393.
• Gottfredson, L. S. (1997). "Mainstream Science on Intelligence: An Editorial with 52 Signatories, History, and Bibliography (Reprinted from the Wall Street Journal, 1994)" (PDF). Intelligence. 24 (1): 13–23. doi:10.1016/S0160-2896(97)90011-8. {{cite journal}}: Unknown parameter |month= ignored (help) appeared originally as "Mainstream Science on Intelligence" in Wall Street Journal, December 13, 1994.
• Gottfredson, L. S. (2005b). "What If the Hereditarian Hypothesis Is True" (PDF). Psychology, Public Policy, and Law. 11: 311–319. doi:10.1037/1076-8971.11.2.311.
• Hacker, Andrew (2005). "The Truth About the Colleges". The New York Review of Books. 52 (17). {{cite journal}}: Unknown parameter |month= ignored (help)
• Herrnstein, R. J. and Murray, C. (1994). The Bell Curve: Intelligence and Class Structure in American Life. New York: Free Press. ISBN 0-02-914673-9. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)CS1 maint: multiple names: authors list (link)
• Jank, Wolfgang (2004). Old World vs. New World: Evolution of Nobel Prize Shares (PDF). Department of Decision & Information Technologies, University of Maryland. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)
• Jensen, A. R. (1969). "How Much Can We Boost IQ and Scholastic Achievement". Harvard Educational Review. 39: 1–123.
• Jensen, A. R. (1973). Educability and Group Differences. London: Methuen. ISBN 0-06-012194-7.
• Jensen, A. R. (1993). "Spearman's Hypothesis Tested with Chronometric Information-Processing Tasks". Intelligence. 17 (1): 47–77. doi:10.1016/0160-2896(93)90039-8. {{cite journal}}: Unknown parameter |month= ignored (help)
• Jensen, A. R. (1998b). The g Factor: The Science of Mental Ability. Westport, CT: Praeger Publishers. ISBN 0-275-96103-6.
• Jensen, A. R. and Whang, P. A. (1994). "Speed of Accessing Arithmetic Facts in Long-Term Memory: A Comparison of Chinese-American and Anglo-American Children". Contemporary Educational Psychology. 19: 1–12. doi:10.1006/ceps.1994.1001.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• jinfo.org (2004). "Jewish Nobel Prize Winners," Accessed 9 June 2005.
• Jones, Garett, and Schneider, Joel W (2005). "Intelligence, Human Capital, and Economic Growth: a Bayesian Averaging of Classical Estimates (BACE) Approach" ( – ). {{cite journal}}: Cite journal requires |journal= (help); External link in |format= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
• Kayser, M., Brauer, S. and Stoneking, M. (2003). "A genome scan to detect candidate regions influenced by local natural selection in human populations". Mol Biol Evol. 20 (6): 893–900. doi:10.1093/molbev/msg092. PMID 12717000. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
• Litwack, Leon How Free is Free? Harvard University Press: 2009 ISBN 9780674031524
• Loehlin, J. C., Lindzey, G. and Spuhler, J. N. (1975). Race Differences in Intelligence. San Francisco: W. H. Freeman. ISBN 0-7167-0754-3. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)CS1 maint: multiple names: authors list (link)
• Lynn, R. (1991a). "Race Differences in Intelligence: A Global Perspective". Mankind Quarterly. 31: 255–296.
• Lynn, R. (1991b). "The Evolution of Racial Differences in Intelligence". Mankind Quarterly. 32: 99–173. {{cite journal}}: Cite has empty unknown parameter: |month= (help)
• Lynn, R. (2001). The Science of Human Diversity: A History of the Pioneer Fund. Lanham, MD: University Press of America. ISBN 0-7618-2041-8.
• Lynn, R. (2006). Race Differences in Intelligence: An Evolutionary Analysis. Washington Summit Books. 1593680201. {{cite book}}: Unknown parameter |month= ignored (help)
• Lynn, R., Hampson, S., and Magee, M. (1984). "Home Background, Intelligence, Personality and Education as Predictors of Unemployment in Young People". Personality and Individual Differences. 5: 549–57. doi:10.1016/0191-8869(84)90029-1. {{cite journal}}: Cite has empty unknown parameter: |month= (help)CS1 maint: multiple names: authors list (link)
• Lynn, R. and Holmshaw, M. (1990). "Black-White Differences in Reaction Times and Intelligence". Social Behavior and Personality. 18: 299–308. doi:10.2224/sbp.1990.18.2.299. {{cite journal}}: Cite has empty unknown parameter: |month= (help)CS1 maint: multiple names: authors list (link)
• Lynn, R. and Shigehasa, T. (1991). "Reaction Times and Intelligence: A Comparison of Japanese and British Children". Journal of Biosocial Science. 23 (4): 409–416. doi:10.1017/S0021932000019519. PMID 1939289. {{cite journal}}: Cite has empty unknown parameter: |month= (help)CS1 maint: multiple names: authors list (link)
• Lynn, R. and Vanhanen, T. (2002). IQ and the Wealth of Nations. Westport, CT: Praeger. ISBN 0-275-97510-X. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)CS1 maint: multiple names: authors list (link)
• MacArthur, R. S. (1968). "Some Differential Abilities of Northern Canadian Native Youth". International Journal of Psychology. 3: 43–51. doi:10.1080/00207596808246642.
• Mackintosh, N. J. (1998). IQ and human intelligence. Oxford; New York: Oxford University Press. ISBN 0-19-852368-8.
• Mall, F. P. (1909). "On Several Anatomical Characters of the Human Brain, Said to Vary According to Race and Sex, with Special Reference to the Weight of the Frontal Lobe". American Journal of Anatomy. 9: 1–32. doi:10.1002/aja.1000090102.
• "Innately Inferior or Equal?" in The Struggle for Equality by Princeton University historian James M. McPherson (Princeton University Press: 1964)
• Morton, S. G. (1839). Crania Americana; or, a Comparative View of the Skulls of Various Aboriginal Nations of North and South America. To Which Is Prefixed an Essay on the Varieties of the Human Species. Philadelphia: Simpkin Marshall & Co.
• Murray, C. (2005). "The Inequality Taboo" ( – ). Commentary Magazine. 120 (2): 13–22. {{cite journal}}: External link in |format= (help); Unknown parameter |month= ignored (help)
• Murray, C. and Herrnstein, R. J. (1994). "Race, Genes and IQ - an Apologia". New Republic. 211 (18): 27–37. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
• Neisser, U. (1997). "Never a Dull Moment". American Psychologist. 52: 79–81. doi:10.1037/0003-066X.52.1.79.
• Neisser, U., Boodoo, G., Bouchard, T. J., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J. and Urbina, S. (1996). "Intelligence: Knowns and Unknowns" (PDF). American Psychologist. 51 (2): 77–101. doi:10.1037/0003-066X.51.2.77. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
• Nisbett, R. E. (2005). "Heredity, Environment, and Race Differences in IQ: A Commentary on Rushton and Jensen (2005)". Psychology, Public Policy, and Law. 11: 302–310. doi:10.1037/1076-8971.11.2.302.
• Nisbett, R.E. (2009). Intelligence and How to Get It: Why Schools and Cultures Count. W.W. Norton & co. ISBN 0393065057.
• Ogbu, J. U. (1978). Minority Education and Caste: The American System in Cross-Cultural Perspective. San Diego, CA: Academic Press.
• Pearl, R. (1934). "The Weight of the Negro Brain". Science. 80 (2080): 431–434. doi:10.1126/science.80.2080.431. PMID 17816046.
• Pinker, Steven (2006). "The Edge Annual Question — 2006: What is Your Dangerous Idea?". The Edge. {{cite journal}}: Unknown parameter |month= ignored (help)
• Plomin, R., DeFries, J. C., McClearn, G. E. and McGuffin, P. (2001). Behavioral Genetics (4th Ed.). New York: Freeman. ISBN 0-7167-5159-3. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)CS1 maint: multiple names: authors list (link)
• Purdey, J. E., University of Melbourne (2002). http://eprints.unimelb.edu.au/archive/00000840/
• Reynolds, C. R., Chastain, R. L., Kaufman, A. S., & McLean, J. E. (1987). "Demographic characteristics and IQ among adults: Analysis of the WAIS-R standardization sample as a function of the stratification variables". Journal of School Psychology. 25: 323–342. doi:10.1016/0022-4405(87)90035-5.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Roth, P. L., Bevier, C. A., Bobko, P., Switzer, F. S. and Tyler, P. (2001). "Ethnic Group Differences in Cognitive Ability in Employment and Educational Settings: A Meta-Analysis". Personnel Psychology. 54 (2): 297–330. doi:10.1111/j.1744-6570.2001.tb00094.x. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
• Rowe, D. C.; Rodgers, Joseph (2005). "Under the Skin: On the Impartial Treatment of Genetic and Environmental Hypotheses of Racial Differences". American Psychologist. 60 (1): 60–70. doi:10.1037/0003-066X.60.1.60. PMID 15641922. {{cite journal}}: Unknown parameter |month= ignored (help)
• Rushton, J. P. (1989a). "Japanese Inbreeding Depression Scores: Predictors of Cognitive Differences between Blacks and Whites". Intelligence. 13: 43–51. doi:10.1016/0160-2896(89)90005-6.
• Rushton, J. P. (2000). Race, Evolution, and Behavior: A Life History Perspective (3rd ed.). Port Huron, MI: Charles Darwin Research Institute. ISBN 0-9656836-1-3.
• Rushton, J. P. (2005). "(Book review) Lynn Richard, Race Differences in Intelligence: An Evolutionary Analysis" (PDF). Personality and Individual Differences: In press.
• Rushton, J. P. and Jensen, A. R. (2003). "African-White IQ Differences from Zimbabwe on the Wechsler Intelligence Scale for Children—Revised Are Mainly on the g Factor" (PDF). Personality and Individual Differences. 34: 177–183. doi:10.1016/S0191-8869(02)00192-7.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Rushton, J. P. and Jensen, A. R. (2005a). "Thirty Years of Research on Race Differences in Cognitive Ability". Psychology, Public Policy, and Law. 11: 235–294. doi:10.1037/1076-8971.11.2.235. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
• Smedley, A. and Smedley, B. D. (2005). "Race as Biology Is Fiction, Racism as a Social Problem Is Real: Anthropological and Historical Perspectives on the Social Construction of Race" (PDF). American Psychologist. 60 (1): 16–26. doi:10.1037/0003-066x.60.1.16. PMID 15641918. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
• Snyderman, M. and Rothman, S. (1988). The IQ Controversy, the Media, and Public Policy. New Brunswick, NJ: Transaction Books. ISBN 0-88738-839-6. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)CS1 maint: multiple names: authors list (link)
• Sowell, T. (1981). Ethnic America: A History. New York: Basic Books. ISBN 0-465-02075-5. {{cite book}}: Cite has empty unknown parameter: |coauthors= (help)
• Stajich, J. E. and Hahn, M. W. (2005). "Disentangling the effects of demography and selection in human history". Molecular Biology and Evolution. 22 (1): 63–73. doi:10.1093/molbev/msh252. PMID 15356276. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
• Sternberg, R. J. (2005). "There Are No Public-Policy Implications: A Reply to Rushton and Jensen (2005)". Psychology, Public Policy, and Law. 11: e72. doi:10.1037/1076-8971.11.2.295. {{cite journal}}: Cite has empty unknown parameter: |month= (help)
• Stock, Gregory (2002). Redesigning Humans: Our Inevitable Genetic Future. Boston: Houghton Mifflin. p. 194. ISBN 0-618-06026-X.
• Storz, J. F., Payseur, B. A. and Nachman, M. W. (2004). "Genome Scans of DNA Variability in Humans Reveal Evidence for Selective Sweeps Outside of Africa". Molecular Biology and Evolution. 21 (9): 1800–1811. doi:10.1093/molbev/msh192. PMID 15201398.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Suzuki, L. and Aronson, J. (2005). "The Cultural Malleability of Intelligence and Its Impact on the Racial/Ethnic Hierarchy". Psychology, Public Policy, and Law. 11 (2): 320–327. doi:10.1037/1076-8971.11.2.320. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
• Vint, F. W. (1934). "The Brain of the Kenya Native". Journal of Anatomy. 48: 216–223.
• Voight, B. F., Kudaravalli, S., Wen, X., Pritchard, J. K. (2006). "A Map of Recent Positive Selection in the Human Genome". PLoS Biology. 4 (3): e72. doi:10.1371/journal.pbio.0040072. PMC 1382018. PMID 16494531. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link) CS1 maint: unflagged free DOI (link)
• Wade, Nicholas (2006). Before the Dawn: Recovering the Lost History of Our Ancestors. New York: Penguin Press. ISBN 1-59420-079-3.
• Wicherts, J. M., Dolan, C. V., Hessen, D. J., Oosterveld, P., van Baal, G. C. M., Boomsma, D. I. and Span, M. M. (2004). "Are intelligence tests measurement invariant over time? Investigating the nature of the Flynn effect". Intelligence. 32 (5): 509–537. doi:10.1016/j.intell.2004.07.002.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Wright, W. D. (2007). Crisis of the Black Intellectual. ISBN 0–88378–251–0. {{cite book}}: Unknown parameter |nopp= ignored (|no-pp= suggested) (help)

External links

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Collective statements

• APA Task Force Examines the Knowns and Unknowns of Intelligence
• Statement on "Race" and Intelligence. American Anthropological Association. Adopted December 1994.
• Mainstream Science on Intelligence. Intelligence, v24 n1 p. 13–23 January–February 1997

Review papers

• James Flynn and Charles Murray debate – news summary
• June 2005 issue of Psychology, Public Policy, and Law, Vol. 11, No. 2.
  • Thirty Years of Research on Race Differences in Cognitive Ability J. Philippe Rushton & Arthur R. Jensen
  • There Are No Public-Policy Implications Robert J. Sternberg
  • What if the Hereditarian Hypothesis is True? Linda S. Gottfredson
  • Heredity, Environment, and Race Differences in IQ Richard E. Nisbett
  • The Cultural Malleability of Intelligence and Its Impact on the Racial/Ethnic Hierarchy Lisa Suzuki & Joshua Aronson
  • Wanted: More Race Realism, Less Moralistic Fallacy J. Philippe Rushton & Arthur R. Jensen
• Race, Genetics and IQ Richard E. Nisbett (PDF)
• The Inequality Taboo Charles Murray archived version
• Race and IQ: A Theory-Based Review of the Research in Richard Nisbett’s Intelligence and How to Get It J. Philippe Rushton & Arthur R. Jensen

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