Hereditarianism

Hereditarianism (aka Jensenism"Introduction to Jensenism". In: C. L. Brace, G. R. Gamble, and J. T. Bond, eds., Race and Intelligence. (1971). Anthropological Studies No. 8. Washington: American Anthropological Association. pp. 4-9.) is a racist pseudoscience that argues mean differences in IQ between human populations (socially constructed races and ethnic groups) are significantly the result of genetics. Proponents of hereditarianism typically argue (following Jensen, 1973) that the black-white IQ gap in the United States is 50% to 75% caused by genetic factors (although some argue as high as 80% to 100%) while 25% to 50% environmental factors.
As mentioned by Linda Gottfredson (2005):
The scientific consensus position on this issue is that there is no evidence for any genetic components that explain the racial IQ gap.Nisbett et al 2012Turkheimer, Harden, Nisbett, 2017 As stated by Stephan Ceci and Wendy M. Williams:
==History==
Probably the first argument for hereditarianism was made in 1869 by Francis Galton who used scores on mathematical and civil-service tests instead of IQs, and used ancestral lineages of the subjects to measure proximity to "great" men.Hereditary Genius: An Inquiry into Its Laws and Consequences by Francis Galton (1st ed., 1869; 2nd ed., 1892) hosted at galton.org Galton also coined the term "eugenics".Inquiries into Human Faculty and Its Development by Francis Galton (1883) hosted at galton.org In the early 20th century, before IQ tests were popular (although sometimes used) racists made different arguments to establish a racial hierarchy in intelligence e.g. the pseudoscientific theory intelligence is correlated to brain size, with whites having the average largest brains and blacks the smallest. This was falsified by Franz Boas (1938) who showed that Eskimos have the largest mean brain-sizes, without asserting their superiority.“Race,” in General Anthropology edited by Franz Boas, pp. 95–123. New York: D. C. Heath. While it is true cranial capacity on average slightly differs by ethnic group, Beals et al. (1984) found smaller cranial capacities are found in warmer climates, while larger in colder; the variation in brain-size between populations is caused by natural selection.https://www.journals.uchicago.edu/doi/10.1086/203138 There's also some evidence that brain size correlates moderately with intelligence: a 2005 meta-analysis found a correlation of r=0.33, implying that brain size explains about 0.33*0.33=11% of the variation in intelligence.Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence, Intelligence, Michael A. McDaniel, 2005, 33(4): 337-356 But more recent evidence suggests that this and other previous estimates of the brain size-intelligence relationship were inflated, and that the actual relationship is much weaker. Accordingly, "it is not warranted to interpret brain size as an isomorphic proxy of human intelligence differences."of associations between human brain volume and intelligence differences: How strong are they and what do they mean?
In 1958 published The Testing of Negro Intelligence; by this time the use of IQ and other standardized tests of intelligence had become politicized by segregationists as a backlash against the Brown v. Board of Education (1954) decision to desegregate public schools. Shuey argued the black-white IQ gap is largely the result of genetic factors to justify racial segregation. However, Pettigrew (1964) reported he was able to find only three American psychologists (including Shuey and her PhD supervisor, Henry Garrett, a segregationist) out of 21,000 members of the American Psychological Association, who were hereditarians.Pettigrew, Thoras F., (1964). A Profile of the American Negro. D. Van Nostrand Company: Princeton. This is likely because it was not until 1968 that all forms of segregation had been declared unconstitutional by the Supreme CourtSee and and most racists wouldn't have become interested in hereditarianism until segregation had formally ended.
In 1969, the psychologist Arthur Jensen published a controversial paper "How Much Can We Boost IQ and Scholastic Achievement" in Harvard Educational Review suggesting genetic factors are "strongly implicated" in average group differences in IQ between blacks and whites:
This view became known as Jensenism based on the idea mean differences in IQ between populations have high between-group heritability. Some contemporary hereditarians include: Richard Lynn, Helmuth Nyborg, Emil Kirkegaard, Jordan Lasker, Gerhard Meisenberg, Heiner Rindermann, Michael A. Woodley of Menie, Paul Irwing, Jonatan Pallesen, Adam Perkins, Davide Piffer, Roger Pearson, John Fuerst, James Thompson, David Becker, Jared Taylor, Peter Frost, Frank Ellis, Michael Levin, Kenya Kura, Jan te Nijenhuis, Noah Carl, Edward Dutton, Fróði Debes, Stefan Molyneux, Gregory Cochran, Nicholas Wade, Guy Madison, Linda Gottfredson, Seymour Itzkoff, Frank Miele, Richard Haier, Edward M. Miller, Kevin MacDonald, Andrew Sabisky, Satoshi Kanazawa, Neven Sesardić, James Watson, Aurelio J. Figueredo and Dimitri van der Linden. Many of these individuals have published in the white supremacist journal Mankind Quarterly and OpenPsych pseudojournals, while nearly all of them are known to have right-wing to far-right/alt-right political beliefs. According to Snyderman & Rothman (1988) individuals with traditional conservative political views are "more likely than liberals to believe that genes play a causal role in race and class differences in IQ".Snyderman, M., and Rothman, S. (1988). The IQ Controversy, the Media and Public Policy. Transaction Books. p. 134.
Recently, the Aporia Magazine is promoting hereditarianism and many eugenicists and hereditarians have appeared on its podcast. The magazine is managed by Matthew Archer, Bo Winegard, Noah Carl and Diana Fleischman."About Aporia". Aporia Magazine.
===1973 survey===
In 1973, 341 American Psychological Association members were asked whether they disagreed or agreed with Jensen's statement (quoted above). The survey revealed 60% disagreed, compared to only 28% who agreed and 2% unsure.Robert W. Friedrichs, (1973). "The Impact of Social Factors Upon Scientific Judgment: The ‘Jensen Thesis’ as Appraised by Members of the American Psychological Association". Journal of Negro Education. 42: 429-438. There is therefore scientific consensus against hereditarianism despite claims to the contrary by hereditarians.
===The Bell Curve===
The controversy over race and IQ culminated in 1994 with the publication of The Bell Curve.
==Black-white IQ gap==
The black-white IQ gap refers to the mean IQ difference between self-identified black and white Americans that hereditarians claim is 15 IQ points (e.g. Jensen, 1969). However, Turkenheimer et al. 2017 argue the 15 point gap is historical, and that the gap has been substantially narrowed in the last few decades; as the difference was found to be 9.5 IQ points in 2006:
In other words, the mean IQ of black Americans has risen from 85 to 90.5; the mean IQ of white Americans is about 100.See Table 3.2 "IQs of Europeans Outside Europe" (USA) in Lynn, R. (2006). Race Differences in Intelligence. Washington Summit Publishers.
==Racialism==
Most racialists who nowadays call themselves "race realists" are proponents of hereditarianism. The exception includes a small number of academics who argue for the existence of human races, but maintain the black-white IQ gap has zero or a trivially small genetic basis e.g. Michael O. Hardimon who defends a minimalist concept of races "characterized by nothing more than outward physical differences and health-related biological susceptibilities."Al-Shawaf, R. (2017). Rethinking Race: The Case for Deflationary Realism by Michael O. Hardimon. The National Book Review. Spencer (2014) argues for a similar biological race definition, and states his theory in terms of genetics "does not entail that there are aesthetic, intellectual, or moral differences among races."Spencer, Q. (2014). "A Radical Solution to the Race Problem". Philosophy of Science. 81(5): 1025-1038. The pioneer of racialist non-hereditarianism was Theodosius Dobzhansky, who was an outspoken proponent of the idea human races exist, but published a paper criticizing Jensen's hereditarianism hypothesis,Dobzhansky, T. (1973). "Race, Intelligence and Genetics". Psychol. Today. 7(7): 97-101. argued for race equality,Dobzhansky, T. (1971) 'Race Equality', in R. H. Osborne (ed.) The Biological and Social Meaning of Race (San Francisco: Freeman). pp. 13–24 and in his book Genetic Diversity and Human Equality (1973) also rejected hereditarianism, given the lack of evidence and reality environmental factors most likely explain the black-white IQ gap.
Because non-hereditarianism is a minority viewpoint within racialism and hereditarianism is racist, Hardimon (2017) re-labels himself as a minimalist race proponent opposed to a racialist to avoid the negative connotations or harmful affect of racialism: "The minimalist concept of race provides a nonmalific alternative to the racialist concept of race".Hardimon, M. (2017). "Minimalist Race Concept" in: Zack, N. ed. The Oxford Handbook of Philosophy and Race. Oxford University Press. p. 159. Non-hereditarianist racialism while more reasonable than hereditarianism because it rejects racism and white supremacism, is still a pseudoscience since human races don't exist as biological constructs, but are social constructs, e.g. some ethnic groups considered to be "white" today weren't a century ago (see ).
==Racism==
Hereditarians view racial inequality in IQ as predominantly genetic, rather than largely or entirely the product of socioeconomic environmental factors and hence argue "equalizing opportunities cannot, in fact, remove black/white disparities in IQ"J. Philippe Rushton, "The American Dilemma in World Perspective" in Jared Taylor's The Real American Dilemma, 1998, p. 11. because of a natural race hierarchy in intelligence. This is obviously racist, and proponents of hereditarianism often describe anti-hereditarians as "egalitarians", e.g. according to J. Philippe Rushton (1995) it is a "politically correct equalitarian fiction" that "races are genetically equal in cognitive ability".https://link.springer.com/article/10.1007/BF02088001
===Asian supremacism?===
Hereditarianism in the early 20th century was explicitly white supremacist with whites at the top of the IQ hierarchy, East Asians in the middle, and blacks as the bottom. However, in the late 20th century Richard Lynn, J. Philippe Rushton and several other hereditarians began to change the racial hierarchy, placing East Asians at the top of the pyramid. Whereas early 20th century hereditarians also argued whites have the largest brains, Rushton would now argue Asians do. Contemporary hereditarians try to silence their critics and deny being racist by pointing out they cannot be white supremacists if they're arguing East Asians on average are smarter than whites. However, this is widely considered a ploy to deflect charges of racism, while at the same time maintaining blacks are mentally inferior; after all, even in the revised pyramid, blacks are still placed at the bottom by hereditarians:
 
Despite hereditarians putting East Asians at the top of the IQ hierarchy, they often still attempt to claim white superiority over East Asians anyway, e.g. the hereditarian James Thompson cites a pseudoscience talk presented at the London Conference on Intelligence that maintains "Asians are bright, but not curious"James Thompson, Asians: Bright, But Not Curious? The Unz Review, 15 September 2015."Learning Without Questioning – Why Asians do not win Nobel prizes". London Conference on Intelligence, 2014. Kenya Kura. and Lynn (2008) states "North East Asians have a higher IQ than Europeans, but their creative achievements have been less."Race Differences in Intelligence, Creativity and Creative Achievement. Hereditarians argue that while East Asians have higher IQ's than whites, they're far less creative and inventive.
==Heritability of IQ==
Heritability is a statistical concept (H/h²) that describes how much of phenotypical variation is accounted for by genotypical variation. Moore DS, Shenk D. The heritability fallacy. Wiley Interdiscip Rev Cogn Sci. 2017 Jan;8(1-2). doi: 10.1002/wcs.1400. Epub 2016 Dec 1. PMID: 27906501. This should not be confused with cause, e.g. a trait might be under strong genetic control, but has 0 heritability because there is no variation, for example everyone is born with two legs:
While there are no conclusively-identified genes that affect human intelligence, some research, such as that of geneticists Robert Plomin and John DeFries, propose that the heritability of IQ in human populations is around .50.
*Mackenzie, B. (1984). "Explaining race differences in IQ: The logic, the methodology, and the evidence". American Psychologist. 39(11): 1214-1233, citing: Plomin, R., & DeFries, J. C. (1980). "Genetics and intelligence: Recent data. Intelligence. 4: 15-24. However, this says absolutely nothing about the cause of IQ group differences between populations; broad-sense heritability is formally defined as the proportion of phenotypic variation (VP) within a population due to variation in genetic values (VG) and should not be confused with between-group heritability.Wray, N. & Visscher, P. (2008). Estimating trait heritability. Nature Education. Stephen Jay Gould (1980) cautioned not to confuse the two:
LewontinLewontin, R. C. (1970). "Race and intelligence". Bulletin of the Atomic Scientists. 26 (3): 2–8. (1970) and Loehlin (1992) provide a useful thought experiment in plant genetics, i.e. two populations of corn have extremely high heritability for a trait, but mean group differences between them are entirely caused by environmental rather than genetic factors; therefore between-group heritability is zero, despite within group heritability nearly 100%:
===Jensen's straw man===
Proponents of hereditarianism such as Jensen (1970, 1973) and Jensen & Rushton (2005) have always acknowledged the aforementioned difficulty, but argue that if two or more populations share a high heritability for a trait or character, it increases probability that average group differences are caused by genes and between-group heritability is above 0:
This argument from mathematical logic has been criticized for lack of empirical support.Mackenzie, B. (1980). "Hypothesized genetic racial differences in IQ: A criticism of three proposed lines of evidence". Behaviour Genetics. 10: 225-234. While it may be theoretically true, it has never been demonstrated in any test. Jensen also never tried to quantify an estimate for between-group heritability from this argument and only ever claimed high within-group heritability is evidence for non-zero between-group heritability, supporting hereditarianism. This is arguably a straw man since almost all scientists are not against the possibility group differences in IQ are negligibly (1-5%) caused by genes, which is above zero, but most these scientists are against hereditarianism.Harwood (1976) points out that the geneticists Richard Lewontin, Walter Bodmer and Jerry Hirsch "accept the plausibility (but not likelihood)" of a small genetic component in race differences in IQ; labelling all three as environmentalists (anti-hereditarians). To this list can be added L. L. Cavalli-Sforza; see his article "Intelligence and Race". (1970). Scientific American. 223(4): 19-29. Earl Hunt former president of the International Society for Intelligence Research thus noted:
Gould (1994) for example in his critical review of The Bell Curve didn't rule out the possibility that genes play a very minor role in average group differences in IQ: "the strong circumstantial case for substantial [environmental] malleability and little average genetic difference" (emphasis added).Gould, S. J. (1994). Curveball. The New Yorker, November 28. Similarly, Nisbett (2005) who published a paper heavily criticizing Jensen & Rushton (2005) doesn't deny the possibility genes are negligibly involved in explaining the black-white IQ gap, i.e. "close to zero" meaning not absolutely nil:
Therefore concerning between-group heritability: anti-hereditarians either argue for 0% genes, but accept the possibility of a very small percentage of genes (e.g. Lewontin, 1970; Gould, 1994; Nisbett, 2005) or argue for the latter (Loehlin et al. 1975; Hunt, 2010).Loehlin et al. in Race Differences in Intelligence (1975) are critical of Jensen's hereditarianism, but favour a minor role of genetics in the black-white IQ gap rather than 0%; in their appendix they estimate between-group heritability at 12.5%, although this is tentative and probably an overestimation since they note, between-group heritability is "more easily accommodated in an environmentalist framework" (p. 238) and so a negligible role for genes (1-5%) is more plausible. Earl Hunt in Human Intelligence (2010) rejects both hereditarianism (as 50-75% or 80% genes) and 0% genes; while emphasising environment, he instead favours an "intermediate" position (p. 435); he provides two examples of low percentage estimates, 3% and 5-15%, but cautions evidence to try to quantify the exact % is currently lacking (p. 436). Note Jensen defined hereditarianism as the view genetics explains between 50% and 75% of the black-white IQ gap and not a figure close to zero (e.g. 3%), so it's intellectually dishonest to try to redefine hereditarianism to mean, say, 97% environment and only 3% genes:
However, instead of trying to test and demonstrate this, both Jensen and Rushton throughout their careers would focus on trying to falsify zero between-group heritability, that they described as the "only environmental"Jensen, A. R. (1998). The g factor. Westport, CT: Praege. p. 465. or "only culture" view.Jensen & Rushton, 2005. Charles Murray often uses the same straw man and defines hereditarianism as only above-zero between-group heritability to argue "if you say it is likely that there is any genetic component to the black-white difference in test scores, the roof crashes in on you."http://www.aei.org/publication/bell-curve-20-years-later-qa-charles-murray/ This is false, since it would mean absurdly classifying anti-hereditarians who accept the possibility or likelihood there is a very minor genetic component involved in the black-white IQ gap, as hereditarians.
Knapp et al. (1996) criticize Murray's use of Jensen's straw man:
They also criticize Herrnstein & Murray's (1994) book The Bell Curve for deceptively claiming to be "agnostic" about between-group heritability:
Herrnstein & Murray (1994) extensively quote and cite Jensen in their work, as well as rely heavily on the pseudoscientific racist theories of J. P. Rushton and Richard Lynn. Laughably, Herrnstein & Murray (1994) defend Rushton, by saying his research on race and intelligence is "not that of a crackpot or bigfoot" and is "plainly science" (p. 667).
===Default hypothesis===
Having failed to actually provide any evidence for hereditarianism, Jensen in 1998 argued that hereditarianism should be accepted as the default hypothesis:
 
This argument is refuted by anthropologist C. Loring Brace (1999) who points out the default hypothesis is the null hypothesis i.e. zero between-group heritability.Brace, C. L. "An Anthropological Perspective on "Race" and Intelligence: The Non-Clinal Nature of Human Cognitive Capabilities". Journal of Anthropological Research. 55(2): 245-264.
==Rindermann et al. surveys== 
===2017===
In 2017 Heiner Rindermann and colleagueshttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC4804158/ published a survey on experts opinion of why there are "large differences in cognitive ability and intelligence studies" between cross-national populations. This survey is now quoted by proponents of hereditarianism as proof their view is mainstream. However, the study is flawed for several reasons:
* The survey was emailed to 1345 individuals, but only 265 (20%) responded and just 71 (5%) participated in the survey.
* 14 (20%) survey participants weren't experts, being non-psychologists, including 2 economists (3%) and 1 sociologist (2%). 
* The survey acknowledged "one researcher suggested in an email that only politically biased researchers would respond to the questionnaire".
* Some participants had no relevant scientific qualifications at all i.e. the criteria to participate in the survey was to have either published articles in peer-reviewed journals on intelligence/cognitive abilities or have attended intelligence conferences and presented research, e.g. ISIR. The journal Intelligence and ISIR conferences (where the survey was announced) have allowed far-right politically biased individuals such as Emil Kirkegaard to publish articles and present talks, despite being non-scientists with no qualifications.
The survey itself despite these issues and bias, hardly lends support to hereditarianism since it showed that overall "experts attributed about one-sixth to one-fifth of international ability differences to genes (cross-national: 16.99%, single-country: 19.72%)", but that this was "still well below the rated impact of environmental factors (around 50%)." In actual fact if one combines the other non-genetic factors with environmental factors, this equates to around 80% environmental which is the complete opposite of Jensen's default hypothesis of 80% genetic–20% environmental between-group heritability; note Jensen (1973) originally defined hereditarianism as the view genes cause at least 50% of the black-white IQ gap.
Turkenheimer et al. (2017) criticize the survey, noting: 
===2013===
In 2013, Rindermann and colleagueshttps://figshare.com/articles/2013_survey_of_expert_opinion_on_intelligence/1295234 delivered a presentation at a ISIR conference that included a survey of expert opinion of the "sources of US black-white differences in IQ":
* 0% of differences due to genes: 17% of experts.
* 0-40% of differences due to genes: 42% of experts.
* 50% of differences due to genes: 18% of experts.
* 60-100% of differences due to genes: 39% of experts.
* 100% of differences due to genes: 5% of experts.
The 0% and 100% views reported above are included in the "0-40% of differences due to genes" and "100% of differences due to genes" respectively (since 42% + 18% + 39% = 99% of experts.). This study is quoted by hereditarians who argue it shows their view is mainstream. However, this is erroneous for five reasons: (1) the environmentalist viewpoint was never solely 0% of differences due to genes, since anti-hereditarians have always accepted the possibility genes are negligibly involved (above zero, but close to zero e.g. 3%) in between-group heritability. (2) For this reason clearly more than 17% of experts are anti-hereditarians (3) The largest amount of experts argue for "0-40% of differences due to genes" which is lower than Jensen's threshold of defining hereditarianism as at least 50%, although “50%”, for the purpose of the survey, can really be anywhere between 45% and 55%. (4) The study suffers from the same bias as the other survey. (In this case, the survey was emailed to 1237 individuals, but only 228 (18%) participated in the survey, of which just 70 completed it.) (5) The survey isn't peer-reviewed.
The final results of the survey were published in Intelligence.Rindermann, H., Becker, D., & Coyle, T. R. (2020). Survey of expert opinion on intelligence: Intelligence research, experts’ background, controversial issues, and the media. Intelligence, 78, 101406. https://doi.org/10.1016/j.intell.2019.101406
==Arguments against hereditarianism==
===The non-validity and non-heritability of IQ===
Although most psychologists agree IQ (as a measure of intelligence) has statistical reliability, makes predictions and reliably measures important elements of intelligence,Turkheimer, E. 1990. “Consensus and Controversy About IQ”. Contemporary Psychology. Vol. 35. No. 5: 428-430). a minority of experts argue IQ is invalid and arguably due to competing theories on the nature of intelligence, the concept of IQ itself is still somewhat controversial. One school of thought posits the existence of g-factor or General Intelligence, a single measurable factor underlying all mental activity and various specific factors, specific abilities that come into play in particular kinds of cognitive tasks. Even scientists who agree that G exists don't necessarily agree on its precise nature. There is also the "Multiple intelligence theory" which says that intelligence isn't a single entity and that there are distinct types of intelligence that each exist independently of one another; so if a person exhibits one type of intelligence that doesn't indicate them being high or low on another type. One thing that should be emphasized that even though IQ tests themselves arguably for sure do measure some degree of various cognitive abilities namely verbal fluency, mathematical ability, etc., there is no universally accepted operational definition of "intelligence" within the field of psychology itself. Benisz, Mark & Willis, John & Dumont, Ron. (2018). Abuses and Misuses of Intelligence Tests: Facts and Misconceptions. 10.7551/mitpress/9780262037426.003.0016. This by extension makes the argument that IQ tests for certain measure intelligence a bit shaky given there is no agreed upon consensus to what "intelligence" even is. None the less this does not necessitate that IQ tests themselves have no scientific legitimacy, or reliable applications. It is still the case IQ tests are intended to measure the existence of general intelligence, though the degree to which they do is not universally accepted.
===Race is a social construct===
Hereditarians usually study IQ differences between populations in the sense of broad regions or continents, e.g. J. P. Rushton's Race, Evolution, and Behavior (1995) divides most of the world into three large racial groupings: Caucasoids (Europeans, West Asians, Indians and North Africans), Negroids (Sub-Saharan Africans) and Mongoloids (Northeast and Southeast Asians). This has been criticized on the basis the groupings are arbitrary and useless since they contain populations that have differential mean IQs; Rushton ignored the huge variability within his racial groupings and aggregated populations that are dissimilar.Lieberman, L. (2001). "How Caucasoids got such big crania and why they shrank: from Morton to Rushton". Current Anthropology. 42: 69-95. Analysing the mean IQ of populations on a subcontinental level is also inappropriate, for example different countries or ethnic groups in Europe vary on average by up to 12 IQ points.Richard Lynn and Tatu Vanhanen in their IQ and the Wealth of Nations (2002, pp. 73-80) provide the following national IQ means (bold = lowest and highest): Albania, 90; Belgium, 100; Bulgaria, 93; Croatia, 90; Denmark, 98; Estonia, 97; Finland, 97; France, 98; Germany, 102; Greece, 92; Hungary, 99; Iceland, 98; Ireland, 93; Italy, 102; Macedonia, 93; Malta, 95; Netherlands, 102; Norway, 98; Poland, 99; Portugal, 95; Romania, 94; Slovakia, 96; Spain, 97; Sweden, 101; Switzerland, 101; Ukraine, 96; UK, 100. Turkenheimer et al. (2017) discuss the problems with race, and favour instead to analyse average IQ differences between populations at a more local level say Swedes and Greeks, rather than clustering both these ethnic groups into a broader "white" category:
The fact there are self-identified black Americans who have predominantly white American ancestry shows why race is a social, not biological construct. There is also the issue "whiteness" has changed definition; some ethnic groups e.g. Italians who were not considered white in the early 20th century, today are in US political discourse. This is relevant to the black-white IQ gap, since Italians have the highest mean IQ in Europe (102) according to Lynn & Vanhanen (2002) and Lynn (2006). If Italian-Americans are not included as white, this lowers the mean white IQ. Furthermore, in a few cases even ethnic groups by country may be unsuitable population units to analyse average IQ differences since subpopulations (by local city, province or district) may show a disparity in mean IQ scores; this is noticeable among the Han Chinese who differ by up to 7 IQ points depending on China province.Lynn, R., and Cheng, H. (2013). "Differences in intelligence across thirty-one regions of China and their economic and demographic correlates". Intelligence. 41(5): 553-559.
===Racial mixture studies===
If the black-white IQ gap is significantly due to genes, self-identified black Americans with the most white American ancestry should have average higher IQ scores than those with less white ancestry (genetic studies reveal black Americans range anywhere from between 1% and 98% white American ancestry).Mersha, T. B., and Abebe, T. (2015). "Self-reported race/ethnicity in the age of genomic research: its potential impact on understanding health disparities". Hum. Gen. 9(1): 1-15.6 However studies have repeatedly shown black Americans with predominantly white American ancestry don't have higher average IQs and racial admixture studies fail to support hereditarianism (Nisbett, 2005; Colman, 2016):
===Adoption studies===
Nisbett (2005) argues adoption studies (e.g. Tizard, 1972; Moore, 1986) are evidence against hereditarianism since they tend to show when middle-class black children are raised by middle-class white families in America or in a highly enriched institutional environment, their average IQs are significantly higher than black children raised by black families.Tizard, B., Cooperman, A., and Tizard, J. (1972). "Environmental effects on language development: A study of young children in long-stay residential nurseries". Child Development. 43: 342–343.Moore, E. G. J. (1986). "Family socialization and the IQ test performance of traditionally and transracially adopted Black children". Development Psychology. 22: 317-326.
===Lack of evidence===
As mentioned, the default hypothesis is the null hypothesis, i.e. zero between-group heritability (0% genes). This has never been falsified. For this reason several scientists e.g. Eric Turkheimer, Richard E. Nisbett argue "there's still no good reason to believe black-white IQ differences are due to genes."https://www.vox.com/the-big-idea/2017/6/15/15797120/race-black-white-iq-response-critics Nisbett (2005) however does not deny the possibility genes are negligibly involved in between-group heritability, but sees no reason right now to argue for this since the null hypothesis (0% genes) is the unfalsified default hypothesis.
===Significant rises in IQ===
Over 14 years (1984-1998), a study found that IQ scores in Kenyan children increased by 11.22 to 26.3 IQ points depending on how test results were converted into IQ, an increase greater than the Flynn effect in developed countries.Daley, T. C., Whaley, S. E., Sigman, M. D., Espinosa, M. P., & Neumann, C. (2003). IQ on the Rise: The Flynn Effect in Rural Kenyan Children. Psychological Science, 14(3), 215-219. https://pdfs.semanticscholar.org/d824/d41d360d8660b64b44e5c0067f50725a78a4.pdf Since the population essentially remained genetically identical throughout the 14-year period, Daley et al. (2003) proposed that improved healthcare, nutrition, parental literacy, smaller families, and education as explanations. The authors note that parasitic diseases (which cause anemia and thereby reduce intelligence) and malnutrition declined over the 14-year period. Under the 11.22 IQ points per 14 years conclusion, a gain of 24 points could occur over 30 years according to the Flynn effect, assuming that environmental conditions continue to improve. This shows that improvements to the environment can have an appreciable effect on IQ, thereby casting doubt on the use of raw IQ data to prove racial superiority.
===Underreporting of African IQ===
Lynn and Vanhansen (2006) found that many Subsaharan African countries had IQs in the 60s and 70s.http://gentlecynic.net/Articles/IQ%20and%20Global%20Inequality.pdf The book was co-authored by Richard Lynn, who has been funded by the Pioneer Fund, and is the source of the colour-coded map of IQ often used by "race realists".https://web.archive.org/web/20110727175000/http://www.pioneerfund.org/Grantees.html 
Data points used by Lynn and Vanhansen (2006) are almost always unrepresentative. Hilariously, the IQ of 59 for Equatorial Guinea given by Lynn and Vanhansen (2006) is actually from a study of developmentally-disabled children in Spain. Lynn and Vanhansen (2006) has been criticized by Wicherts et al. (2009) for using lower IQ data points while not including higher IQs (possibly unintentional because they may not have had access to scientific journals from Africa).Wicherts, J. M., et al., A systematic literature review of the average IQ of sub-Saharan Africans, Intelligence (2009), 15-17. doi:10.1016/j.intell.2009.05.002 The report calls below-70 mean IQ figures for Subsaharan Africans "untenable", and estimates a mean IQ of around 81 after correction for methodological issues. The difference between an IQ of sixty-something and an IQ of 81 is important: after correcting for the Flynn effect, the pure-Nordic Danish population in the 1950s would also have had an IQ of around 80. Thus, more realistic estimations of African IQ might permit it to rise to first-world levels through the Flynn effect given sufficient economic development.
==Links==
* The Wikipedia article on 
* Race and intelligence. Psychology Wiki — useful overview with sources
==References==
Category:Pseudoscience
Category:Racialism
Category:Racism