User:Nick Connolly/RaceIQ

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This is an essay; it contains the advice and/or opinions of one or more Wikipedia contributors. It is not a policy or guideline, and editors are not obliged to follow it.

_{This is an essay outlining what I believe is the central topic in the race-intelligence article. It is currently OR, SYN and POV - so don't treat it as an article if you come across it. It is also a work-in progress. Offers of help are welcome! Also note that the "Q" on my keyboard sticks so a solitary I isn't egomania but IQ with the Q missing. Lastly, I am an outlier on the regression line of spelling and IQ :)}

The Race and IQ hypothesis (also known as the "genetic hypothesis"^[1], the "hereditarian hypothesis"^[2], or "Jensenism"^[3]) is a controversial topic within psychometrics. In particular the hypothesis that differences in IQ between different ethnic groups is primarily due to genetic differences in those groups has provoked controversy in both the academic and popular press. The hypothesis has been criticised by anthropologists as relying on out-moded notions of race, by biologists as misunderstanding issues of within group and between group heredity, by sociologist and psychologists as failing to acknowledge the effects of socioeconomic status and racism and by psychometricians who have criticised the underlying data. Supporters of the hypothesis have presented a plethora of indirect evidence for the hypothesis and have also claimed that, while unproven, the hypothesis is a worthwhile area of inquiry. At another level the hypothesis has been characetrised as racist as it implies a fundamental inequality between racial groups. Critics have raised questioned the funding of the research and in particular the role of the Pioneer fund. Supporters have, in turn, claimed that an important area of inquiry has been supressed for political reasons and that policy implications should be regarded as seperate from academic inquiry. The status of research into "race and intelligence" as science is also disputed.

Contents 1 Key concepts 2 Outline of the hypothesis 2.1 The 1969 hypothesis 2.1.1 Within-group heritability 2.2 Characterization of alternatives 2.3 Emprical tests 2.3.1 Spearman's hypothesis 2.3.2 Brain size and evolution 2.3.3 ECT 2.3.4 Structural equation modeling 2.3.5 Transracial adoption 2.3.6 Admixture 2.3.7 Global comparisons 3 Scientific criticism of the hypothesis 3.1 Race and anthropology 3.2 Heredity 3.3 Intelligence 3.4 Confounding variables 3.5 Psychometrics 3.6 Evolutionary theory 4 Views of Key People 4.1 Proponents 4.2 Critics 4.2.1 Biologists - Geneticists 4.2.2 Anthropologists and Sociologists 4.2.3 Psychologists 4.2.4 Psychometricians 4.2.5 Economists 5 Notable studies 5.1 Twin Studies 5.2 Studies of Educational Interventions 5.3 Studies of Social Interventions 5.4 Studies of IQ Scores across ethnic groups 5.5 Studies of IQ scores by nationality or national origin 5.6 ECT and Psychophysical studies 6 Notable Books 7 Notes

[edit] Key concepts

• Race (see main article Race). Race is a term with multiple definitions. The data relevant to this article primarily deals with IQ by self-identified racial or ethnic groups or national groups. Researchers claiming a genetic Race-IQ link have applied their own definitions to describe what they mean by race in a genetic sense. These definitions may not comply with common usage in either anthropology or biology. [these last two are probably controversial.^[4]]
• Intelligent quotient (see main article IQ) . The validity of IQ as a measure of intelligence is itself a matter of dispute. The psychometric properties of IQ scores are also a matter of ongoing debate.
• General intelligence or g (see main article g). General intelligence is a view of intelligence derived from factor analysis of IQ scores - that is a single statistical factor covers a significant amount of the variance in IQ scores. This single dimension view of intelligence is disputed by some psychologists (see Multiple intelligence and the validity of the factor-anayltic evidence has also been disputed.
• The achievment gap (see main article Achievement gap). The well-documented gap in IQ scores between different ethnic groups in the USA is claimed to be explained by the genetic race-IQ hypothesis. A variety of other explanations exist that offer different enviromental and genetic factors (and combinations thereof) as explanations, as well as fundamental questions of test-bias and the role of racism in IQ testing.

[edit] Outline of the hypothesis

[edit] The 1969 hypothesis

The central theoretic axis of the 1969 argument is:

1. High within-group heritability of IQ for both blacks and whites
2. Empirical data (mainly about the relation of various environmental variables to variation in IQ) implies
3. non-zero between-group heritability

This argument is commonly mistaken to mean either that #1 entails #3 logically or that #1 itself inductively establishes #3. Instead, Jensen concluded: "So all we are left with are various lines of evidence, no one of which is definitive alone, but which, viewed all together, make it a not unreasonable hypothesis that genetic factors are strongly implicated in the average Negro-white intelligence difference".

[edit] Within-group heritability

Adoption, twin, and other behavioral genetic studies have shown that differences in IQ are lower for people who are genetically similar, leading to the hypothesis that difference between individuals in general-intelligence is primarily determined by differences in their genes.

[edit] Characterization of alternatives

Jensen enumerates two classes of alternatives to the genetic hypothesis: common environmental factors or "X-factor" theories. Given high within-group heritability, for between group differences to be explained by common environmental factors alone, the two groups must differ to a very large extent with respect to those common environmental factors. In fact, the environmental differences would need to be so large to explain the observed IQ differences that such hypotheses would seem implausible given the size of observed environmental differences in candidate factors.

The following table shows the effect of within-group heritability on the common environmental differences required to explain a 1 SD difference in IQ:

Within-Group Heritability	0%	10%	20%	30%	40%	50%	60%	70%	80%	90%	100%
Required environmental difference	1	1.05	1.12	1.19	1.29	1.41	1.58	1.82	2.24	3.16	impossible

X-factor theories take the form of an example given by Lewontin to argue against Jensen. [Corn experiment] A hypothetical X-factor has zero within-group variance, but it varies between groups and causes the observed IQ differences. Jensen argues that it is very difficult to name a genuine candidate X-factor. For example, SES and educational inequalities do not qualify as X-factors. Prima facie, discrimination appears to be an X-factor. Flynn argues that discrimination is not a genuine X-factor as it can only plausibly operate through mechanisms involving common environmental factors.

[edit] Emprical tests

In the 1969 paper, Jensen writes that theoretical considerations alone cannot decide whether the genetic hypothesis is correct and that empirical tests are required. In the 2005 review paper, Jensen and Rushton outline various predictions of the genetic hypothesis and argue that the published data supports it more than the alternative.

[edit] Spearman's hypothesis

Factor-analysis of IQ scores have led some researchers to claim that a single factor (g or general intelligence) underpins variance in IQ scores within populations. Spearman's hypothesis states that "variation in the size of the mean W-B [White-Black] difference across various mental tests is a positive function of variation in the tests’ g loadings" (Jensen, 1998, p. 372). This is an accessory hypothesis, and the causal hypothesis does not rest on any particular theory of the phenotypic structure of group differences. Jensen argues that 1. BW differences are correlated with the extent that a test measures g; 2. the extent that a test measures g is correlated with the heritability of the test and other biological factors^[5]. Therefore, 3. BW differences track the effects of biological and heritable variation at the phenotypic level.

The validity of the statistical method Jensen used to support Spearman's hypothesis have been criticized. New statistical methods were unable to distinguish between a number of alternative models and thus were unable to prove or disprove Spearman's hypothesis.

[edit] Brain size and evolution

The genetic contribution to within population difference in complex traits such as IQ comes from the effects of large number genes found throughout the genome. Genes contribute to difference between individual when the genes themselves come in different forms, called alleles. In that sense, differences in alleles underly genetic difference between individuals. The frequency of alleles vary between populations. On average 85% of the total variation in alleles occurs within populations and 15% occurs between populations. In the case of two populations and two alleles of a single gene, this average translates into allele frequencies of 30%/70% for one population and 70%/30% for another population. If group differences in intelligence have a genetic basis, this would have to be due to differences in frequencies of alleles associated with IQ. It is implausible that all alleles associated with IQ have exactly the same frequencies in every population. What is unknown is whether the allele frequency difference that are important for IQ line up in such a way that different population have different average IQs or whether the different alleles balance out to have zero net effect on average IQ. For the allele frequencies to line up in the same direction, natural selection would have to have affected their frequencies. Thus, if group differences in intelligence have a genetic basis this would have to be due to past selective pressure.

Natural selection affects a trait when the trait is associated with reproductive fitness. That is, if the number of surviving children an individual has is associated with a trait, such as IQ, then the alleles associated with that trait will increase in frequency in the population and the average value of the trait in the population will change. For group difference in IQ to have a genetic basis, IQ would have to have been under selection during the time after the groups diverged, and also, the net effect of natural selection would have to have been different between populations.

Rushton

[edit] ECT

Elementary cognitive tasks are, as the name suggests, simple tasks that involve some basic cognition. Proponents of the g-hypothesis have looked at ECTs as a means of assessing general intelligence in a way that is manifestly culture-free. The underlying hypothesis is that there is a close link between general-intelligence and neural efficiency ^[6]. summary^[7] The effectiveness and relevance of ECT studies has been criticised (see below).

[edit] Structural equation modeling

[edit] Transracial adoption

[edit] Admixture

[edit] Global comparisons

[edit] Scientific criticism of the hypothesis

The hypothesis has been criticised at several levels and across disciplines.

[edit] Race and anthropology

Anthropologist's views on race have changed significantly during the twentieth century. The extent to which races are valid biological concepts has diminished and has been replaced with a view of races as being primarily a social construct. The genetic race-IQ hypothesis runs counter to this trend and has been criticised by anthropologist for this reason.

[edit] Heredity

Biologists and geneticists have criticised the claims of heredity and general intelligence. Enviromental and genetic factors are not mutually independent and hence while heredity may explain variance within a group, enviroment can account for variance across groups. IQ research can't control for these variables systematically and demonstrations of heredity for people within a consistent enviroment can't evaluate the effect of changing the enviroment in some significant way (eg the effect of racial discrimination).

[edit] Intelligence

Cognitive science and psychology do not have a single explantory model of intelligence. Significantly intelligence may or may not be a single thing. If intelligence is multidimensional then IQ tests may not measure all relevant aspects, further genetic or enviromental factors may cause differences in the way various aspects of intelligence intercorrelate. Consequently differences in IQ may represent differences in different kinds of intelligence rather than differences in an overall level of intelligence. The notion of general intelligence may not be valid as an underlying theory of intelligence.

[edit] Confounding variables

As well as potential multidimensionality in intelligence, IQ scores are subject to variation that is due to factors that are not neccesarily intelligence. Cultural bias in a test may depress the score for people from a different culture. Emotional or behavioural factors may affect test scores. The theory of stereotype threat suggests that test scores are lowered if test-takers percieve that the test is in an area that their group stereotypically perform poorly.

[edit] Psychometrics

IQ tests and IQ research are typically conducted within Classical test theory, a theoretical model of testing that has been superceded by Item Response Theory and more sophisticated measurement models such as the Rasch model. From an IRT perspective IQ tests produce ordinal data, a form of data which does not constitute measurement. As such arithmetic differences in IQ are not properly meaningful as individual IQ points may not represent equal increases of intelligence.

[edit] Evolutionary theory

If group differences in intelligence have a genetic basis this would have to be due to past selective pressure. The evolution of human intelligence is still a matter of research. However, there is no obvious reason why there would be different selective pressure on intelligence in different geographic areas. Evolutionary psychology typically assumes that the human mind is the product of adaptations in pre-agricultural times. Evolutionary psychology is itself controversial and some evolutionary psychologists such as Kanazawa have offered scenarios were people in colder climbs needed to solve more complex problems as an explanation for the finding that existing differences in test scores are highly correlated with climate. Critics have argued that similar arguments can be claimed for any latitude. The doctrine of eugenics suggests that genetic changes are possible over a relatively short time spans. Genome scans find strong signatures of natural selection in the genomes of several human populations, with strong evidence for positive selection during the last 10 thousand years^[8]. The example of lactase persistence indicates that phenotypically meaningful human evolution had led to some population differentiation since the advent of agriculture. Lactase persistence maps to the LCT gene in Europeans, which shows the same kind of signatures detected throughout the genome.^[9]

[edit] Views of Key People

This controversial topic has attracted the interest of numerous academics. Proponents have typically been associated with the hereditarian view of general intelligence. Critics have come from a wide range of scientific disciplines.

[edit] Proponents

The following people have all, to some extent, contributed to the genetic race-IQ hypothesis. The extent to which any one may have overtly asserted the hypothesis varies and they may also have changed their views over time.^[10]

• Charles Spearman : regarded by many as the founder of classical test theory, Spearman's work on factor anaylsis was instrumental in promoting the notion of a biological general intelligence "g" as the primary factor underlying intelligence tests.^[11]
• Hans Eysenck : A leading proponent of the hereditarian view of intelligence in the second half od the twentieth century. Eysenck outlined his views in Race, Intelligence and Education (1971) and also a signatory to the Mainstream Science on Intelligence editorial in the Wall Street Times which gave a qualified defence of the science in The Bell Curve.
• Arthur Jensen : Like Eysenck Jensen has been a noted proponent of the hereditarian position. However, is views on the nature and measurability of intelligence have changed over time. His most significant contribution to the debate on race and IQ was in the paper "How Much Can We Boost I.Q. and Scholastic Achievement?" in the Harvard Educational Review. This paper argued that educational programs in the US designed to boost the achivement of black school children had not only failed but could only ever be of limited effectiveness due to genetic differences. The paper provoked both an academic and a popular controversy. Jensen was also a signatory to the Mainstream Science on Intelligence editorial.
• J. Philippe Rushton : With Richard Lynn, probably the most proliic author on the subject. Psychologist and author of Race, Evolution, and Behavior, a book which argues that East Asians have significant cognitive advantages of other population groups due to genetics. Rushton has also been an editor of the journal Intelligence, which has published many articles relevant to both race and IQ. More controversially Rushton has, since 2002, been the president of the Pioneer Fund - a primary source of funding for race-IQ research which has also been accused of being a racist organisation by the Southern Poverty Law Center, an anti-racist organization.
• Linda Gottfredson, a psychologist, best known for authoring Mainstream Science on Intelligence [3], an editorial originally published in the Wall Street Journal in 1994, signed by 51 other researchers. This editorial defended the position of the authors of The Bell Curve.
• Charles Murray : Political scientist and commentator noted as being the co-author of The Bell Curve.
• Richard Herrnstein : A behavioural psychologist and researcher into animal learning. Along with Charles Murray authored The Bell Curve, a controversial book which presented for a general audience some of the arguments and evidence for the genetic view of race and IQ.
• Richard Lynn : In recent times, possibly the most prolific researcher in this area, along with Rushton. Lynn has published many papers on racial and geographic differences in measures of intelligence. He has also revived research in areas such as dysgenics, eugenics, and craniometry. Lynn's research has been heavily criticised.
• Satoshi Kanazawa : a proponent of evolutionary psychology who has attemtpted to reconcile EP with traditional views of general intelligence ^[12]. More notable for his views on gender-differences Kanazawa has also written favourably about Lynn's research.
• David C. Rowe : psychologist who make use of structural equation modelling to empirically test the genetic hypothesis.^[13][14] A critic of the Dickens-Flynn model.^[15] His final paper reviewed his past studies and proposed new empirical tests.^[16]

Also associated have been Nobel Prize recipients physicist William Shockley, and biologists James Watson and Francis Crick^[17].

[edit] Critics

Critics of the hypothesis cross many disciplines. Many papers have been written critical of the claims made by Jensen, or in The Bell Curve. The people listed below do not represent an exhaustive list, rather they represent particular criticisms or are authors of notable works relevant to the debate.

[edit] Biologists - Geneticists

• Stephen J. Gould : Paleontologist and polymath, Gould's Mismeasure of Man was a detailed critque of the history of attempts to measure human intelligence and to ascribe differences to race. Gould was critical of the factor-analysis view of general-intelligence and regarded it as a misunderstanding of the statistical process. Gould critcised Jensen's work and in a later edition also examined the claims made in the Bell Curve
• Richard C. Lewontin : Biologist. Leowontin examined Jensen's heritability claims. In particular he suggested a thought experiment involving corn seed and the height of plants grown in different circumstances to demonstrate the fallacy of judging between group hereidty based on within group heridty. Criticially reviewed.^[18]
• Jared Diamond : Diamond's quest is to explain why Eurasian civilizations, as a whole, have survived and conquered others, while refuting the belief that Eurasian hegemony is due to any form of Eurasian intellectual, genetic, or moral superiority. Diamond argues that the gaps in power and technology between human societies do not reflect cultural or racial differences, but rather originate in environmental differences powerfully amplified by various positive feedback loops. Diamond outlined his views in the book Guns, Germs and Steel.

[edit] Anthropologists and Sociologists

• Ashley Montagu : An anthropologist noted in particular for his attempts to change attitudes on race within the field of anthropology. Notable also as an editor of the book Race and IQ - a collection of articles critical of the race-IQ claims particularly of the Jensen's 1969 paper. A later expanded edition also looked at the the Bell Curve's claims.
• Leonard Lieberman, reknowned anthropologist, who has been especially critical of the brain size vs intelligence relationship posited by Rushton and Lynn. In his paper, How Caucasoids Got Such Big Crania and Why They Shrank, From Morton to Rushton[4] he deconstructs many of the arguments used by Rushton to support his theory.
• John Ogbu : sociologist, deceased, Nigerian-American , argues that being a "caste-like minority" affects motivation and achievement, depressing IQ scores. He also stated that some students did poorly because high achievement was considered "acting white" among their peers.
• Claude S. Fischer lead author of Inequality by Design: Cracking the Bell Curve Myth

[edit] Psychologists

• James R. Flynn : a psychologist whose work is closely related to Jensen's research but which has reached very different conclusions. Flynn examined a wide range of IQ results and in the process highlighted the wide ranging upward trend of IQ scores over generations. This result, named the Flynn effect by Herrnstien and Murray, appears to confirm a large environmental component in IQ scores. The steady rise also appears to disconfirm the dysgenic trend predicted by the hereditarian view.
• Ulric Neisser : a psychologist and lead author of the American Psychological Association's paper Intelligence: Knowns and Unknowns - a paper designed to clarify current thinking on intelligence in the aftermath of the The Bell Curve.
• Zack Cernovsky, a psychologist specialized in intelligence, who in a paper entitled A critical look at intelligence research[5], levels several profound criticism at both the methodology and the interpretation of data made by the proponents of the hereditarian position.
• Robert Sternberg : originator and proponent of the concept of practical intelligence; argues that intelligence test score differences represent an inappropriate comparison of intelligence differences between groups

[edit] Psychometricians

• Denny Borsboom : A noted psychometrician in the field of item response theory and the Rasch model. Borsboom paper "Attack of the psychometricians" ^[19] is a general critiue of the gulf between adavances in psychometrics and the techniques used by many psychologist researching areas such as IQ and personality tests. Borsboom argues that the work of both Richard Lynn and Hernstein makes a fundamental conceptual error by confusing predictive invariance between groups (i.e. the same test shows is equally good at predicting some other measure for both groups) with measurment invariance (i.e. the same test is measuring the same latent trait between groups. This is not a mere quibble as "In fact, prediction invariance is generally indicative of violations of measurement invariance: if two groups differ in their latent means, and a test has prediction invariance across the levels of the grouping variable, it must have measurement bias with regard to group membership. Conversely, when a test is measurement invariant, it will generally show differences in predictive regression parameters." In other words most of the data on IQ differences between US "blacks" and "whites" is prima-facie evidence of test bias and the fact that the tests are predictively invariant confirms that. See also Borsboom's counter-arguments to Kanazawa ^[20]
• Roger E. Millsap : Borsboom argument (above) is based on an earlier paper by psychometrician Millsap. ^[21]. Millsap has published several papers on measurement bias and in this one examined the issue with particular regard to Spearman's g.
• Jelte Wichers and Conor Dolan: papers on Spearman's hypothesis^[22], the Flynn effect^[23], and stereotype threat^[24][25]

[edit] Economists

• Thomas Sowell : conservative economist, African American, argues that difference in test scores between groups within societies are not uncommon and that they are of a social origin [6]
• Roland G. Fryer Jr : economist, African American -- A 2006 study titled An Empirical Analysis of "Acting White" by Roland G. Fryer, Jr. at Harvard University and Paul Torelli suggested that the phenomenon has a significant effect on black student achievement, especially in schools with high interracial contact and among high achieving students, but little or no effect in predominantly black or private schools.[7]

[edit] Notable studies

A wide range of research is cited in relation to the hypothesis. The quality of the methodology, particulalrly in identifying the race of the subject and in measuring their IQs, has been of varying quality.

[edit] Twin Studies

The hypothesis requires an adequate estimate of the heritability of IQ. Studies of identical twins have been a major source of data in this area. In particular the IQ scores of identical twins who, due to adoption, have been brought up seperately. Some notable twin studies include:

• Cyril Burt's twin studies. British psychologist conducted a number of studies to gauge the hereritability of IQ. Much of his data is now disputed. Notably Arthur Jensen was one of the first to cast doubts on Burt's studies.
• Thomas J. Bouchard Jr.; David T. Lykken; Matthew McGue; Nancy L. Segal; Auke Tellegen (October 12, 1990). Minnesota Study of Twins Reared Apart. Science, Oct 12, 1990 v250 n4978 p223(6).
• [REVIEW] Thomas J. Bouchard, Jr., Matt McGue (2003). Genetic and Environmental Influences on Human Psychological Differences. [8]

[edit] Studies of Educational Interventions

Jensen's provocative paper specifically addressed concerns over programs such as Head Start. Other attempts to boost academic achievment of ethnic groups have also occurred and been studied. The success and failure of such schemes is also hotly disputed as are the factors which have played a role in them.

• Head Start program started in the mid 1960s and critcised in Jensen's 1969 paper.
• The Carolina Abecedarian Project

(List from Is Early Intervention Effective? Some Studies of Early Education in Familial and Extra-Familial Settings Urie brofenbrenner Ch17 Race & IQ Ashley Montagu (ed.))

• Howard University Preschool Program
• Perry Preschool Project
• Philadelphia Project Temple University
• Indiana Project
• Infant Research Project
• Verbal Interaction Project

[edit] Studies of Social Interventions

Minnesota Transracial Adoption Study

[edit] Studies of IQ Scores across ethnic groups

• Armed Forces Qualifying Test (AFQT) : data from this test was used extensively in the Bell Curve
• 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.

[edit] Studies of IQ scores by nationality or national origin

[didn't screen for notability here]

• IQ and the Wealth of Nations
• IQ and Global Inequality
• Rindermann, H. (2007). The g-factor of international cognitive ability comparisons: The homogeneity of results in PISA, TIMSS, PIRLS and IQ-tests across nations. European Journal of Personality, 21, 667−706.
• Heiner Rindermann, Relevance of education and intelligence at the national level for the economic welfare of people, Intelligence Volume 36, Issue 2, March-April 2008, Pages 127-142.
• Heiner Rindermann, Relevance of education and intelligence for the political development of nations: Democracy, rule of law and political liberty, Intelligence (In press)
• Garry A. Gelade, The geography of IQ, Intelligence (In Press).
• Steven M. Shatz, IQ and fertility: A cross-national study, Intelligence Volume 36, Issue 2, , March-April 2008, Pages 109-111.
• Earl Hunt and Werner Wittmann, National intelligence and national prosperity, Intelligence Volume 36, Issue 1, January-February 2008, Pages 1-9.
• Richard Lynn and Jaan Mikk, National differences in intelligence and educational attainment, Intelligence Volume 35, Issue 2, March-April 2007, Pages 115-121.
• Deborah L. Whetzel and Michael A. McDaniel, Prediction of national wealth, Intelligence Volume 34, Issue 5, September-October 2006, Pages 449-458.
• Nigel Barber, Educational and ecological correlates of IQ: A cross-national investigation, Intelligence Volume 33, Issue 3, May-June 2005, Pages 273-284.
• Dickerson, R. E. (2006). Exponential correlation of IQ and the wealth of nations. Intelligence, 34, 291−295.
• Lynn, R., Meisenberg, G., Mikk, J., & Williams, A. (2007). National IQs predict differences in scholastic achievement in 67 countries. Journal of Biosocial Science, 39, 861−874.

[edit] ECT and Psychophysical studies

• Jensen's chronometric work
• Dreary and Crawford (1998) - critical
• Lynn, Chan and Eysenck (1991) Reaction Times and intelligence in Chinese and British children, Perceptual and Motor Skills; also Flynn (1991) , analysis of above study, Reaction times show that both Chinese and British children are more intelligent than one another Perceptual and Motor Skills
• Matsuzawa - Ali the chimp
• AEP average evoked potential studies... (need to look them up)

[edit] Notable Books

• The Bell Curve
• The g Factor
• The Mismeasure of Man
• Guns, Germs, and Steel
• Loehlin, J. C., Lindzey, G., & Spuhler, J. N. (1975). Race differences in intelligence. New York: Freeman.
• Race and IQ (ed Ashley Montagu)
• What is Intelligence? James Flynn
• Race, IQ and Jensen. James R. Flynn. London: Routledge & Kegan Paul. 1980. [mostly of historical note]
• Inequality by Design: Cracking the Bell Curve Myth Claude S. Fischer, Michael Hout, Martín Sánchez Jankowski, Samuel R. Lucas, Ann Swidler, & Kim Vos

[edit] Notes