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This article also discusses issues regarding ethnicity and intelligence.

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The study of race and intelligence seeks to determine whether human intellectual abilities vary between races and/or the causes of any differences that appear in the measurements.

Theories about a relationship between race and intelligence have been the subject of speculation and debate since the 16th century. The contemporary debate focuses on the nature, causes, and importance, or lack of importance, of ethnic differences in intelligence test scores and other measures of cognitive ability, and whether "race" is a meaningful biological construct. The question of the relative roles of nature and nurture in causing individual and group differences in cognitive ability is seen as fundamental to understanding the debate.

The modern controversy surrounding intelligence and race focuses on the results of intelligence quotient (IQ) studies conducted during the second half of the 20th century in the United States, Western Europe, and other industrialized nations. There are also controversies over the definition of "race", the definition of "intelligence", and whether the "intelligence quotient" is a satisfactory measure of intelligence; see the respective articles on those subjects for more information.

History

Charles Darwin wrote in Descent of Man : "The races differ also in constitution, in acclimatisation and in liability to certain diseases. Their mental characteristics are likewise very distinct; chiefly as it would appear in their emotional, but partly in their intellectual faculties."

The opinion that there are differences in the brain sizes and brain structures 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".

The writings of 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 estimated 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; findings that continue to spark controversy in academia today.

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.

Contemporary issues

The contemporary debate on race and intelligence is about what causes racial and ethnic differences in IQ test scores.

The modern debate was prompted by psychology professor Arthur Jensen's 1969 publication of the controversial article, "How Much Can We Boost IQ and School Achievement?". In this paper, he "argued that black-white differences in IQ scores might be due to genetic factors" and that if "IQ had a substantial genetic component, remedial education programs to improve IQ should not be expected to raise IQ as they were currently being applied." His article was widely reported in the popular press.

Physicist William Shockley, who shared the 1956 Nobel Prize in Physics, spent much of his later life focused on the questions of race, intelligence, and eugenics. He began giving speeches on population problems and published several controversial papers arguing that intelligence is primarily hereditary. He postulated that the higher reproduction rate of those with lower intelligence was having 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 and pointed out that eugenics was a rationale used by the Nazis. He was attacked in the media and in scientific journals. Shockley described his work on the issue as the most important of his career.

Population geneticist Luigi Luca Cavalli-Sforza on several occasions publicly debated Arthur Jensen and William Shockley arguing that environmental factors could explain the black-white IQ gap.

The Snyderman and Rothman study was published in 1988, showing a liberal media bias on the reporting of race and intelligence. The study indicated the media gave a misleading impression of what the mainstream view is in the scientific community regarding the relative importance of genetic and environmental factors in explaining individual and group differences in IQ. It found that the media regularly presented the views of those who stress that individual and group differences may be substantially genetic as a minority view, however, their 1987 survey of expert opinion found that the opposite was true.

The publication of The Bell Curve in 1994, which included a discussion of racial differences in intelligence, received much attention in the popular press and ignited renewed debate within academia and amongst the general public.

In recent years, the belief that there are no race differences in intelligence or potential has been challenged by scholars such as Charles Murray, Michael Levin, and J. Philippe Rushton and defended by other scholars such as Stephen Jay Gould, Richard Levin, and Richard Lewontin. They claim that, in light of the slight but definite effect that racial origins have on physical traits like medical risk factors and athletic abilities, there is no reason to suppose that such effects do not extend to mental traits. In his 2007 book, Avoid Boring People: Lessons From a Life in Science, Nobel Laureate James D. Watson writes:

There is no firm reason to anticipate that the intellectual capacities of peoples geographically separated in their evolution should prove to have evolved identically.

The Bell Curve

The Bell Curve is a controversial, best-selling 1994 book by the late Harvard professor of psychology Richard J. Herrnstein and American Enterprise Institute political scientist Charles Murray. Its central point is that intelligence is a better predictor of many factors including financial income, job performance, unwed pregnancy, and crime than parents' socioeconomic status or education level. Also, the book argued that those with high intelligence (the "cognitive elite") are becoming separated from the general population of those with average and below-average intelligence, and that this was a dangerous social trend. Much of the controversy concerned Chapters 13 and 14, in which the authors wrote about the enduring racial differences in intelligence and discuss implications of those differences. The authors were reported throughout the popular press as arguing that these IQ differences are genetic, although they state no position on the issue in the book, and write in the introduction to Chapter 13 that "The debate about whether and how much genes and environment have to do with ethnic differences remains unresolved."

Shortly after publication, many people rallied both in criticism and defense of the book. Some critics denounced the book and its authors as supporting scientific racism. A number of critical texts, including The Bell Curve Debate and The Mismeasure of Man (second edition), were written in response to the book.

"Mainstream" statement

A collective statement titled "Mainstream Science on Intelligence" was published in the Wall Street Journal on December 13, 1994. It was written by psychology professor Linda Gottfredson, and signed by Gottfredson and 51 other professors specializing in intelligence and related fields. It listed 25 statements which claimed to uphold findings on the subject of intelligence research discussed in the The Bell Curve. This statement was reprinted in the psychology journal Intelligence in 1997 with additional information and a bibliography. Regarding the cause of racial-ethnic group differences in IQ, the statement says:

There is no definitive answer to why IQ bell curves differ across racial-ethnic groups. The reasons for these IQ differences between groups may be markedly different from the reasons for why individuals differ among themselves within any particular group (whites or blacks or Asians). In fact, it is wrong to assume, as many do, that the reason why some individuals in a population have high IQs but others have low IQs must be the same reason why some populations contain more such high (or low) IQ individuals than others. Most experts believe that environment is important in pushing the bell curves apart, but that genetics could be involved too.

American Psychological Association response

In response to the controversy surrounding The Bell Curve, the American Psychological Association's Board of Scientific Affairs in 1995 established a special task force to publish an investigative report on the research presented in the book. The report, Intelligence: Knowns and Unknowns, agreed with many of the book's statements on intelligence, however, regarding the book's genetic implications, it states:

It is sometimes suggested that the Black/White differential in psychometric intelligence is partly due to genetic differences (Jensen, 1972). There is not much direct evidence on this point, but what little there is fails to support the genetic hypothesis.

The January 1997 issue of American Psychologist published eleven critical responses to the American Psychological Association (APA) report, most of which criticized the report's failure to examine all of the evidence for or against genetic contributions to racial differences in IQ. Charles Murray, for example, responded:

Actually, there is no direct evidence at all, just a wide variety of indirect evidence, almost all of which the task force chose to ignore.

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

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 gap, most educators agree that it must be addressed. They often advocate equitable funding for education.

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.

While not specifically race-related, policies focused on geographical regions or nations may have disproportionate influences on certain racial groups and on cognitive development. Differences in health care, nutrition, regulation of environmental toxins, and geographic distribution of diseases and control strategies between the developing world and developed nations have all been subjects of policies or policy recommendations (see Health and intelligence).

Melvin Konner, professor of anthropology and associate professor of psychiatry and neurology at Emory University, called Bell Curve a "deliberate assault on efforts to improve the school performance of African-Americans". "This book presented strong evidence that genes play a role in intelligence but linked it to the unsupported claim that genes explain the small but consistent black-white difference in IQ. The juxtaposition of good argument with a bad one seemed politically motivated, and persuasive refutations soon appeared. Actually, African-Americans have excelled in virtually every enriched environment they have been placed in, most of which they were previously barred from, and this in only the first decade or two of improved but still not equal opportunity. It is likely that the real curves for the two races will one day be superimposable on each other, but this may require decades of change and different environments for different people. Claims about genetic potential are meaningless except in light of this requirement."

Achievement gap

An achievement gap refers to the observed disparity on a number of educational measures between the performance of groups of students, including groups defined by race or ethnicity.

Eugenics

Since World War II, both the public and the scientific communities have associated eugenics with Nazi abuses, such as enforced racial hygiene, human experimentation, and the extermination of undesired population groups. Beginning in the 1980s, the history and concept of eugenics were again widely discussed as knowledge about genetics advanced significantly; developments in genetic, genomic, and reproductive technologies raised many new questions and concerns about eugenics and what its ethical and moral status is in the modern era. Endeavors such as the Human Genome Project made the effective modification of the human species seem possible again.

A few scientific researchers such as psychologist Richard Lynn, psychologist Raymond Cattell, and doctor Gregory Stock have openly called for eugenic policies using modern technology, but they represent a minority opinion in current scientific and cultural circles. One attempted implementation of a form of eugenics was a "genius sperm bank" (1980–99) created by Robert Klark Graham, from which nearly 230 children were conceived. In the U.S. and Europe, though, these attempts have frequently been criticized as in the same spirit of classist and racist forms of eugenics of the 1930s. Because of its association with compulsory sterilization and the racial ideals of the Nazi Party, the word eugenics is rarely used by the advocates of such programs.

Eugenicists have argued that immigration from countries with low national IQ is undesirable. According to Raymond Cattell "when a country is opening its doors to immigration from diverse countries, it is like a farmer who buys his seeds from different sources by the sack, with sacks of different average quality of contents."

Biotechnology

Gregory Stock argues that modern biotechnology will allow parents to select desired genes in their children. He states "current debates about whether some of the differences among ethnic and racial groups are cultural or biological will soon become irrelevant, given the coming ". He writes that germinal choice technology may one day be able to select or change directly alleles found to influence intelligence or racially identifying traits (such as skin color; see gene SLC24A5), making them susceptible to biotechnological intervention.

Test results

The examples and perspective in this section may not represent a worldwide view of the subject. You may improve this section, discuss the issue on the talk page, or create a new section, as appropriate. (Learn how and when to remove this message)

The gaps found between the average intelligences of races or ethnicities varies depending on the populations studied and the content of the tests used. Black and white populations in the United States are the best studied. Black-White average IQ differences appear to increase with age, averaging approximately 17 points by age 24. According to James Flynn, the overall average Black-White gap has reduced by one third over the last 30 years. However, a large (21,260 children) and probably the most recent (1998) study found that the Black-White gap for young children in reading and math scores was much smaller than in earlier studies. Less controversially, Black-White differences on school achievement tests shrunk over the last 30 years, but some of the improvements did not continue through the 1990s. The Black-White IQ gap 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. Using a variety of statistical techniques, Dolan and colleagues have found that the Black-White IQ gap can be accounted for by differences in g and the other interindividual ability factors measured by IQ tests, and also that IQ tests measure roughly the same mix of abilities in both Black and white populations. 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 United States 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 United States as they do elsewhere. Also Ashkenazi Jewish populations tend to score substantially higher on average than other populations of European ancestry. 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 on tests of visuospatial ability to a greater extent than on tests of verbal ability, whereas the test score differences skew towards higher verbal ability 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.

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 accuracy of the cross cultural IQ scores is highly controversial, but many scholars use the results as an estimate of world-wide IQ scores. Lynn's meta-analysis lists East Asians (105), Europeans (99), Inuit (91), Southeast Asians and Amerindians (87 each), Pacific Islanders (85), Middle Easterners (including South Asians and North Africans) (84), sub-Saharan Africans (67), and Australian Aborigines (62). International achievement test scores, including TIMSS and PISA, have also been used to estimate average IQ world-wide with similar results where data is available. The very low IQ scores reported for sub-Saharan African populations is especially controversial. For example, Wicherts argues that the average IQ of sub-Saharan Africans is poorly measured and is more likely 78. Sternberg, a critic of Rushton and Lynn, reported an average IQ of 70 for "young adolescents" in Kenya. All commenters agree that IQ scores in developing countries are depressed to some extent by environmental conditions, such as macronutrient and micronutrient deficiencies.

Increases in IQ scores over time

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 black American performance today could be higher than the mean white American performance 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. An added complication to this hypothesis is the question of whether the secular IQ gains can be predominantly a real change in cognitive ability. Flynn's face-value answer to this question is "No", and some other researchers have found reason to concur. In terms of the mixture of ability factors 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. Other recent studies have found that g has improved substantially. Cranial vault size has increased and the shape changed during the last 150 years in the US; these changes must occur by early childhood because of the early development of the vault.

Reaction time

In 1991, Richard Lynn tested 1,468 9-year old children consisting of Blacks from South Africa, East Asians from Hong Kong and Japan, and Whites from Britain and Ireland. The content of the tests involved flipping a switch after one or more lights came on. Lynn found that the decision times (the time taken to make a decision about what to do) had a low correlation with IQ data on Raven's Progressive Matrices tests also administered during the same study, and that movement times (the time taken to execute the decision) did not show any correlation. He found that the Asians had the fastest decision times, followed by the Whites, and then by the Blacks. He also determined that the Black children had movement times that were substantially faster than those of Whites and Asians on certain tests. Studies by Jensen have shown similar patterns in response time on tests of arithmetic and international studies by Lynn have also asserted the same trend.

Nature and nurture

The nature versus nurture debates concern the relative importance of an individual's innate qualities ("nature", i.e. nativism, or philosophical empiricism, innatism) versus personal experiences ("nurture") in determining or causing individual differences in physical and behavioral traits. The view that humans acquire all or almost all their behavioral traits from "nurture" is known as tabula rasa ("blank slate"). In a modern context, the issue often relates to estimating the relative contribution of genetic and environmental factors to difference between individuals. However, all commenters agree that these methods cannot and are not intended to distinguish genetic and environmental contributions to the development of individual people. Instead, they are meant to determine the extent to which difference between individuals, for example individual difference in IQ scores, can be attributed to genetic and environmental factors that differ between individuals. Thus, a heritability of 100% does not mean that environmental factors are unimportant for development, but rather that physical or behavioral difference between individuals are not caused by difference in environment.

There is disagreement amongst scientists, scholars, and the public over the extent to which differences in intelligence quotient (IQ) between groups of humans are the result of genetic (nature), environmental (nurture), or the interaction of both factors. The consensus among intelligence researchers is that IQ differences between individuals of the same racial-ethnic group reflect real, functionally and socially significant, and substantially heritable differences in intelligence. There is still substantial debate about the influence of various environmental factors on IQ test score differences between races and ethnic groups in a given country, and whether or not genetics may also play a role.

Much of the research on explaining group differences stems from an observation promoted first by Arthur Jensen and later James Flynn regarding an environmental explanation for group differences. Jensen and Flynn argue that the very high within-group heritability of IQ presents a problem for environmental explanations of group differences in IQ. The high heritability of IQ implies that any environmental factor that varies within populations must have little effect on IQ. This implies that factors that vary within populations cannot contribute much to IQ differences between groups, unless the groups are extremely different with respect to that environmental factor. Differences in social and economic status might fall in this category. Yet there are no environmental factors known to vary that much between groups. Alternatively then, an environmental cause of group differences must vary between groups and not within groups. Effects associated with racism might fall into this category. Based on this reasoning, both Jensen and Flynn believe that the range of plausible environmental causes of group differences is constrained. Flynn believes that a predominately environmental cause will be found. Jensen believes that genetic factors will be found to be involved.

Viewpoints of notable scientists and researchers

Researchers who believe that there is no significant genetic contribution to race differences in intelligence include Flynn (1980), Brody (1992), Neisser et al. (1996), Nisbett (1998), Mackintosh (1998), Jencks and Phillips (1998), and Fish (2002). Some scientists who emphasize cultural explanations do not necessarily exclude a small genetic influence. Reynolds (2000) suggests up to 20% genetic influence be included in the cultural explanation. Researchers who believe that there are significant genetic contributions to race differences in intelligence include McGurk (1953), Garrett (1961), Shuey (1966), Shockley (1968), Eysenck (1971), Baker (1974), Loehlin et al. (1975), Vernon (1979), Lynn (1991a), Waldman et al. (1994), Scarr (1995), Levin (1997), Jensen (1998b), Rushton (2000), and Gottfredson (2005b). Coming advances in genetics and genomics are expected to soon provide the ability to test hypotheses about group differences more rigorously than has as yet been possible.

Genetic

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). In the article "Thirty Years of Research on Race Differences in Cognitive Ability" published in the APA journal Psychology, Public Policy and Law they cite the following evidence to support the hereditarian model:

1. Black–White–East Asian differences in IQ, reaction time, and brain size are observed worldwide in a range of cultures and environments. In the United States, significant Black-White IQ differences are observable at every age above 3 years, within every occupation or socioeconomic level tested, in every region of the country, and at every time since the invention of ability tests.
2. Jensen and others have argued that the magnitude of race differences on different IQ subtests correlate with the extent to which those subtests measures g, which also correlates with measures of the subtests heritability. From these and other findings, they argue that race differences have a partly biological basis.
3. The rising heritability of IQ with age (within all races; studies have found on average in the developed world heritability starts at 20% in infants, rises to 40% in middle childhood, and peaks at 80% in adulthood); and studies showing the virtual disappearance (~0.0) by adulthood of shared environmental effects on IQ (for example, family income, education, and home environment), with adopted siblings partaking in the studies no more similar in IQ than with strangers From these studies, they argue that most suggested environmental explanations for IQ difference between groups do not have a strong enough effect on IQ to fully account for group differences.
4. Studies of US comparisons of both parents to children and siblings to each other finding regression to differing means for different races (85 for Blacks and 100 for Whites) across the entire range of IQs, despite the fact that siblings are matched for shared environment and genetic heritage, with regression unaffected by family socioeconomic status and generation examined

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 transracial adoption, 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..

Environmental

Critics of the significantly genetic view, such as Robert Sternberg, argue that these studies are either flawed and thus inconclusive, or else that they support a primarily environment (<20% genetic) hypothesis. For example, Dolan and Hamaker (2001) argue that the statistical methods linking the Black-White gap to g are insufficient. They reanalyzed the data from several earlier studies and concluded that Spearman's hypothesis is not an "empirically established fact" (i.e., that Black-White IQ differences may be due to differences in common factors other than g) due to insufficient power in the data to choose between alternative models. "This leaves the validity of Spearman's hypothesis, considered a central justification for the genetic explanation, an unresolved question." However, they did confirm that the Black-White IQ gap is not due to measurement artifacts, and is instead due to some measured factor that varies both within and between groups.

Nisbett (2005) lists many studies that 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 .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." 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."

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. 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." 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."

Health

Regarding the IQ gaps in the U.S., numerous explanations beside genetics have been proposed. Joel Wiesen lists more than a hundred. Increased rates of low birth weight babies and lower rates of breastfeeding in Blacks as compared to Whites are some factors of many that have been proposed to affect the IQ gap. The Flynn effect is often cited as evidence that average IQ scores have changed greatly and rapidly, for reasons poorly understood, noting that average IQ in the US may have been below 75 before the start of this effect, and thus some argue that the IQ gap between races could change in the future or is changing, especially if the effect started earlier for Whites.

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 fully explain the gaps found in non-threatening test conditions.

Quality of education

Some researches 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 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 African Americans and Whites 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.

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. Scores 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 student's 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 students cultural background may effect 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 United States. 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."

Caste-like minorities

The book Inequality by Design: Cracking the Bell Curve Myth claims that it is not lower average intelligence that leads to the lower status of ethnic minorities, it is instead their lower status that leads to their lower average intelligence test scores. The following table from the same book illustrates how social status or caste position is related to test scores and school success in nations around the world.

Interpretations

Given the observed differences in IQ scores between certain groups, a great deal of debate revolves around the significance of these observations. Various interpretations of test data lead to a multitude of conflicting conclusions as to which specific explanations the data support.

Jared Diamond's Guns, Germs and Steel instead 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.

J. Philippe Rushton, a professor of psychology at the University of Western Ontario and the current head of the Pioneer fund, has written a controversial book called Race, Evolution, and Behavior: A Life History Perspective. Rushton claims in the book that race is a valid biological concept and that racial differences frequently arrange in a continuum of Mongoloids (Orientals, East Asians) at one extreme, Negroids (blacks, Africans) at the opposite extreme, and Caucasoids (whites, Europeans) in the middle. It has been heavily criticized.

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.

Criticisms

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.

Fluid gF'

A recent theory hypothesizes that fluid cognition (gF) may be separable from general intelligence (g), and that the portion of gF which is distinct from g, called gF', may be very susceptible to environmental factors, in particular early childhood stress. Some IQ tests, especially those used with children, are poor measures of gF' (the part of gF that is distinct from g), which means that the effect of the environment on intelligence regarding racial differences, the Flynn effect, early childhood intervention, and life outcomes may have been underestimated in many studies. The article has received numerous peer commentaries for and against.

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 an area of focus for a few researchers. Some defend the research, saying it has egalitarian aims or that it is pure science; 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.

As to 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 conservative political pundit at 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.

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 reflected 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 U.S. 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. Also, all commenters reject the common misconception that IQ is meant to measure "innate" differences in intelligence, and they agree that average IQ scores on their own say nothing about the cause of the differences.

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 finds 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.

Source of funding

Proponents of genetic explanations of race/IQ correlation, such as Rushton, Lynn, and Jensen, have often been criticized for their intimate links with groups that have historic ties to Nazis and eugenics of the early 19th century, such as the Pioneer Fund. It has been characterized by the Southern Poverty Law Center as 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. Anti-racist Searchlight Magazine described one of these as a "veritable 'who’s who' of American white supremacy.". Beverly Daniel Tatum writes that dominant cultures often set the parameters by which minority cultures will be judged. Minority groups are labeled as substandard in significant ways: for example, blacks have historically been characterized as less intelligent than whites. Tatum suggests that the ability to set these parameters is a form of white privilege. 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.

See also

Theories of Race and Intelligence:

• Hominid intelligence

Publications of Race and Intelligence:

• IQ and the Wealth of Nations
• IQ and Global Inequality
• The Mismeasure of Man
• Race Differences in Intelligence

Theories of other Intelligence links:

• Brain to body mass ratio
• Height and intelligence
• Neuroscience and intelligence
• Sex and intelligence

Notes

1. Andor, L. E., ed. Aptitudes and Abilities of the Black Man in Sub-Saharan Africa: 1784-1963: An Annotated Bibliography. Johannesburg: National Institute for Personnel Research, 1966.
2. "Race as Biology Is Fiction, Racism as a Social Problem Is Real: Anthropological and Historical Perspectives on the Social Construction of Race." by Audrey Smedley and Brian D. Smedley
3. Thirty Years of Research on Race Differences In Cognitive Ability. p. 240
4. Black-White-East Asian IQ differences at least 50% genetic, major law review journal concludes
5. Darwin Descent of Man VII, On the races of Man, published in 1871
6. Broca 1873; Bean 1906; Mall 1909; Morton 1839; Pearl 1934; Vint 1934
7. 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
8. Eugenics: America's Darkest Days
9. Francis Galton:British Psychologist
10. Degler 1992; Loehlin et al. 1975
11. 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 a 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.
12. Lynn 2001 pp. 67–69
13. based on World distribution of the intelligence of indigenous peoples from Lynn (2006) p. vi
14. Jensen 1969
15. http://encarta.msn.com/encyclopedia_761570026_6/Intelligence.html
16. http://www.pbs.org/transistor/album1/shockley/shockley3.html
17. http://encarta.msn.com/encyclopedia_761562270/william_shockley.html
18. Shockley, William. Shockley on Eugenics and Race: The Application of Science to the Solution of Human Problems. ISBN 978-1878465030. {{cite book}}: Check |authorlink= value (help)
19. A Genetic and Cultural Odyssey: The Life and Work of L. Luca Cavalli-Sforza by Linda Stone, pages 76, 168 ISBN 0231133960.
20. Does Race Matter? - Recent Developments
21. Race is More Than Just Skin Deep: A Psychologist's View
22. Wagenseil, P. "DNA Discoverer: Blacks Less Intelligent Than Whites", Fox News, October 18, 2007. Retrieved October 24, 2007.
23. Gottfredson, Linda (December 13, 1994), Mainstream Science on Intelligence. Wall Street Journal, p A18.
24. Mainstream science on intelligence
25. The authors of the report agreed that IQ scores have high predictive validity for individual differences in school achievement. They confirmed the predictive validity of IQ for adult occupational status, even when variables such as education and family background have been statistically controlled. They agree that individual differences in intelligence are substantially influenced by genetics (75% in adults). Consistent with Herrnstein and Murray's findings, they state there is little evidence to show that childhood diet influences intelligence except in cases of severe malnutrition.
26. http://faculty.mwsu.edu/psychology/Laura.Spiller/4503_Tests/intelligence_knowns_and_unknowns.pdf
27. Neisser, U. (1997). "Never a Dull Moment". American Psychologist 52: 79-81.
28. Murray lists race differences in brain size, along with "IQ in sub-Saharan Africa, the results of transracial adoption studies, the correlation of the black-white difference with the g-loadedness of tests, regression to racial means across the range of IQ, or other relevant data" among the evidence omitted from the task force report.
29. Achieving Equitable Education in Calhoun County
30. Educational Studies: A Jrnl of the American Educ. Studies Assoc.
31. 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)"
32. Gottfredson 2005b
33. The Tangled Wing Biological Constraints on the Human Spirit by Melvin Konner, 2nd edition, p. 428
34. See, i.e., Richard Lynn, Eugenics: A Reassessment (Human Evolution, Behavior, and Intelligence) (Praeger Publishers, 2001).
35. Cattell, R. B. (1987). Beyondism: Religion from science. New York: Praeger, p. 187
36. (Template:AYref, p. 194; race and intelligence discussed on pp. 44-47).
37. (Stock 2002, p. 194; race and intelligence discussed on pp. 44-47).
38. ^ James R. Flynn, The Black-White IQ Gap
39. 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).
40. The g Factor. 1998. {{cite book}}: Unknown parameter |Author= ignored (|author= suggested) (help)
41. Dolan, C. V. (1997). A note on Schönemann's refutation of Spearman's hypothesis. Multivariate Behavioral Research, 32, 319-325.
42. Dolan, C. V. (2000). Investigating Spearman's hypothesis by means of multi-group confirmatory factor analysis. Multivariate Behavioral Research, 35, 21-50.
43. 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.
44. Roth et al. 2001
45. Berry, J. W. (1966). Temne and Eskimo perceptual skills. International Journal of Psychology, 1, 207-222.
46. MacArthur, R. S. (1968). Some differential abilities of northern Canadian native youth. International Journal of Psychology, 3, 43-51.
47. 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.
48. Carretta, T. R., & Ree, M. J. (1995). Near identity of cognitive structure in sex and ethnic groups. Personality and Individual Differences, 19, 149-155.
49. IQ and the Wealth of Nations, Race Differences in Intelligence, and IQ and Global Inequality
50. Satoshi Kanazawa, Temperature and evolutionary novelty as forces behind the evolution of general intelligence
51. Steven M. Shatz, IQ and fertility: A cross-national study
52. The decline of the world's IQ
53. ^ Relevance of education and intelligence at the national level for the economic welfare of people
54. Herrnstein and Murray 1994; Lynn 1991a; Lynn 2006
55. 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. {{cite journal}}: Cite has empty unknown parameter: |month= (help)
56. Lynn, R. and Vanhanen, T. (2002). IQ and the wealth of nations. Westport, CT: Praeger. ISBN 0-275-97510-X
57. Rindermann, H. (2006). What do international student assessments measure?. Psychologische Rundschau, 57, 69–86.
58. Relevance of education and intelligence for the political development of nations: Democracy, rule of law and political liberty
59. National differences in intelligence and educational attainment
60. 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.
61. 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.
62. Black Americans reduce the racial IQ gap: Evidence from standardization samples William T. Dickens and James R. Flynn. Oct. 2006
63. Flynn 1987, Flynn 1987b, Flynn 1999, Flynn 1999b
64. Colom et al. 2005
65. Flynn 1999
66. Flynn (2007)
67. Wicherts et al. (2004) 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". In other words, according to this study, some of the inter-generational difference in IQ is attributable to bias or other artifacts, and not real gains in general intelligence or higher-order ability factors.
68. James Robert Flynn (2007) What is Intelligence?: Beyond the Flynn Effect. Cambridge University Press: Cambridge
69. Are cognitive differences between immigrant and majority groups diminishing?TE NIJENHUIS Jan ; DE JONG Mart-Jan ; EVERS Arne ; VAN DER FLIER Henk ; European journal of personality (Eur. j. pers.) 2004, vol. 18, no5, pp. 405-434
70. Secular Gains in Fluid Intelligence: Evidence from the Culture-Fair Intelligence Test Roberto Colom and Oscar Garcia-Lopez, Journal of Biosocial Science (2003), 35: 33-39 Cambridge University Press
71. "Changes in vault dimensions must occur by early childhood because of the early development of the vault." Secular change in craniofacial morphology "During the 125 years under consideration, cranial vaults have become markedly higher, somewhat narrower, with narrower faces. The changes in cranial morphology are probably in large part due to changes in growth at the cranial base due to improved environmental conditions. The changes are likely a combination of phenotypic plasticity and genetic changes over this period." Cranial change in Americans: 1850-1975.
72. Richard Lynn, "Race Differences in Intelligence: A Global Perspective," The Mankind Quarterly 31, no. 3 (1991): 255–96; Means for Progressive Matrices and 12 reaction time measures for 9-year-old children from five countries.
73. Jensen 1993; Jensen and Whang 1994.
74. See Lynn and Shigehisa (1991) for Japan; Chan and Lynn (1989) for Hong Kong and Britain; Lynn (1991) for Ireland; and Lynn and Holmshaw (1990) for South Africa.
75. How Heritability Misleads about Race
76. Reviewed in Neisser et al. (1996). Data from the NLSY as reported in figure adapted from Herrnstein and Murray (1994), p. 288.
77. R. J. Sternberg (2000) Handbook of Intelligence. Cambridge: Cambridge University Press
78. David J. Bartholomew (2004) Measuring Intelligence: Facts and Fallacies. Cambridge: Cambridge University Press
79. Ian J. Deary. (2001) Intelligence: A Very Short Introduction. Oxford: Oxford University Press
80. 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. (Feb 1996). "Intelligence: Knowns and Unknowns". American Psychologist 51 (2): 77-101.
81. Gottfredson, L. S. (Ed.). (1997). Intelligence and social policy . Intelligence, 24(1).
82. Gottfredson, L. S. (1997). Mainstream science on intelligence: An editorial with 52 signatories, history, and bibliography. Intelligence, 24(1), 13-23.
83. Robert Plomin, John C. DeFries, Gerald E. McClearn, and Peter McGuffin (2000) Behavioral Genetics. Worth Publishers; Fourth Edition edition
84. Brody, N. (1992). Intelligence (2nd ed.). San Diego, CA: Academic Press.
85. Snyderman, M., & Rothman, S. (1988). The IQ controversy, the media and public policy. New Brunswick, NJ: Transaction Press.
86. Jensen (1998) The g Factor
87. Flynn (1980) and Flynn (1999)
88. http://en.wikipedia.org/Talk:Race_and_intelligence/references
89. Pinker (2006), Rowe (2005), Stock (2002) pp. 44–47.
90. http://psychology.uwo.ca/faculty/rushtonpdfs/PPPL1.pdf Thirty Years of Research on Race Differences in Cognitive Ability
91. 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
92. Jensen 1998b
93. For example, see Rushton and Jensen (2003); see also Spearman's hypothesis
94. for example, inbreeding depression scores measured in Japan predict the magnitude of the Black-White gap in the United States. (Rushton 1989a)
95. reviewed by Jensen (1998b)
96. Plomin et al. 2001
97. for example, the children of wealthy, high IQ Black parents score lower than the children of poor, low IQ White parents (Jensen 1998b, p. 358); and for Black and White children with an IQ of 120, the siblings of the Black children average an IQ of 100 whereas the siblings of the White children average an IQ of 110; in comparison, for Black and White children with an IQ of 70, the siblings of the Black children average an IQ of 78 whereas the siblings of the White children average an IQ of 85 (Jensen 1973, pp. 107–119))
98. http://www.lrainc.com/swtaboo/taboos/cmurraybga0799.pdf
99. 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)
100. Reviewed by Rushton and Jensen (2005).
101. For example: Nisbett (2005), Suzuki and Aronson (2005), Sternberg (2005), Dickens (2005)
102. HEREDITY, ENVIRONMENT, 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
103. Genetic Differences and School Readiness Dickens, William T. The Future of Children - Volume 15, Number 1, Spring 2005, pp. 55-69
104. 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
105. 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
106. Blood Lead Levels --- United States, 1999--2002 CDC.
107. 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.
108. Aronson, Wilson, & Akert, 2005
109. 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
110. Acculturation, Reading Level, and Neuropsychological Test Performance Among African American Elders Jennifer J. Manly‌, Desiree A. Byrd‌, Pegah Touradji‌, Yaakov Stern‌
111. Cancellation test performance in African American, Hispanic, and White elderly DESIREE A. BYRD, PEGAH TOURADJI, MING-XIN TANG and JENNIFER J. MANLY
112. School Quality and the Black-White Achievement Gap Eric A. Hanushek and Steven G. Rivkin 2006
113. 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
114. 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
115. 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
116. (Salend, Garrick Duhaney, & Montgomery, 2002; Townsend, 2002)
117. Racial Inequity in Special Education. Losen, Daniel J., Ed.; Orfield, Gary, Ed. Harvard Education Publishing Group.
118. (Gay, 2000; Irvine & Armento, 2001; Ladson-Billings, 1994, 2001)
119. 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
120. Color-Blind Ellis Cose. Page 50
121. 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. (The footnotes given are also from this book.)
122. The Bell Curve and many other places.
123. Church Academic Achievement
124. Richard Lynn discussed in Benson Ireland's 'Low' IQ
125. Lynn et al. Home Background
126. Klich Aboriginal Cognition and Psychological Science; Clark and Halford, Does Cognitive Style Account for Cultural Differences?
127. Ogbu, Minority Education and Caste
128. Verster and Prinsloo, The Diminishing Test Performance Gap
129. Raven, The Raven Progressive Matrices esp fig. 2
130. Kugelmass et al., Patterns of Intellectual Ability
131. Das and Khurana, Catse and Cognitive Processes
132. Shimahara, Social Mobility and Education
133. (pp. 34-35).
134. 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).
135. Rushton, J. P. (1995). Race, Evolution, and Behavior: A Life History Perspective (PDF) (2nd special abridged edition ed.). Port Huron, MI: Charles Darwin Research Institute. {{cite book}}: |edition= has extra text (help); Cite has empty unknown parameters: |coauthors= and |month= (help)
136. Pomeranz, Kenneth (2001). The Great Divergence. Princeton, NJ: Princeton University Press.
137. Jones, Eric (1997). The European Miracle. Cambridge: Cambridge University Press.
138. Mokyr, Joel (1992). The Lever of Riches. Oxford: Oxford University Press.
139. North, Douglass (1976). The Rise of the Western World. Cambridge: Cambridge University Press.
140. The attack of the psychometricians. Denny Borsboom. Psychometrika Vol. 71, No. 3, 425–440. September 2006.
141. How similar are fluid cognition and general intelligence? A developmental neuroscience perspective on fluid cognition as an aspect of human cognitive ability, Behavioral and Brain Sciences (2006), 29: 109-125 Cambridge University Press, Clancy Blair. Multiple comments can be seen on Google Scholar.
142. e.g., Sternberg, 2003, pp. 386–387
143. e.g., Sternberg, 2003, pp. 386–387
144. Hunt & Carlson, in press
145. ^ 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. Cite error: The named reference "APA" was defined multiple times with different content (see the help page).
146. Dolan, C. V. (1997). A note on Schönemann's refutation of Spearman's hypothesis. Multivariate Behavioral Research, 32, 319–325.
147. Dolan, C. V. (2000). Investigating Spearman's hypothesis by means of multi-group confirmatory factor analysis. Multivariate Behavioral Research, 35, 21–50.
148. 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.
149. http://www.charlesdarwinresearch.org/PRSL2007.pdf
150. 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.
151. Construct validity of Raven’s Advanced Progressive Matrices for African and non-African engineering students in South Africa.
152. 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.
153. Culture-Fair Cognitive Ability Assessment Steven P. Verney Assessment, Vol. 12, No. 3, 303-319 (2005)
154. 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.
155. 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
156. Tatum, Beverly Daniel (1997). Why are all the black kids sitting together in the cafeteria? And other conversations about race. New York: BasicBooks. ISBN 9780465091270.

References

External links

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 Jan–Feb 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
• The Black-White Test Score Gap (1998) online (page-image) version of ISBN 0-8157-4609-1

Others

• Crippled by Their Culture - Race doesn't hold back America's black rednecks. Nor does racism by Thomas Sowell
• Race and IQ: Part 1, Part 2, Part 3 by Thomas Sowell
• The Skeptic's Dictionary entry on IQ and race
• (Skeptic Magazine): Two book reviews, by Paul R. Gross and Alondra Oubre, of Sarich’s and Miele’s book, Race: The Reality of Human Differences
• Criticism on source material of Bell Curve book
• Poverty and Brain Development in Early Childhood 1999 report
• Miscellaneous articles by Richard Lynn et al.
• Are IQ Tests Biased?
• Scholars Provide an Overview of Explanations for Black-White Test Score Gap
• School Readiness: Closing Racial and Ethnic Gaps
• A review of the field (Jan. 2006) Kohn, Marek, "This racist undercurrent in the tide of genetic research: As taboos fall away, there's a danger that denial of racial difference will be replaced with uncritical acceptance," The Guardian.
• The Lessons of the Ashkenazim: Groups and Genes, Steven Pinker, June 2006, The New Republic.
• Are all races equally intelligent? -- Or: When is knowledge knowledge? by John J. Ray
• Black-White Gap in IQ Scores Closing, Study Finds
• Breaking Free of Nehruby Sanjeev Sabhlok : Chapter 2, section 6 of this book proposes a model of IQ determination which is strongly impacted by the level of freedom (and dignity)

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• Misplaced Pages neutral point of view disputes from March 2008
• Intelligence
• Race and intelligence controversy