[[Image:Sketch-4race-transparent.png|thumb|400px|[[Normal distribution]] showing results of studies comparing [[race]]s and [[ethnic group]]s with [[IQ]] among U.S. test subjects show differences in average test scores, though the [[normal distribution|distributions]] overlap, as seen in this graph based on {{AYref|Reynolds et al.|1987}} (see [[#_note-IQdistribution|footnote 2]] for further references). The causes and meaning of the different average scores for these groups are debated.]] '''Race and intelligence''' is a controversial area of [[intelligence (trait)|intelligence]] research studying the nature, origins, and practical consequences of racial and ethnic group differences in [[intelligence quotient|intelligence test]] scores and other measures of [[cognition|cognitive]] ability.Researchers contributing to this area of inquiry mostly include [[psychology|psychologists]], [[psychometrics|psychometricians]], [[genetics|geneticists]], [[sociology|sociologists]], and [[anthropologists]]. This research is grounded in several controversial assumptions: *the social categories of [[race]] and [[ethnicity]] are [[concordance (genetics)|concordant]] with [[genetics|genetic]] categories, such as [[biogeographic ancestry]]. *[[Intelligence (trait)|intelligence]] is measurable (see [[psychometrics]]) and is dominated by a unitary [[general intelligence factor|general cognitive ability]]. Much of the evidence currently cited is based on [[IQ]] testing in the United States. While the distributions of IQ scores among different racial-ethnic groups overlap considerably, groups differ in where their members cluster along the IQ scale. {{AYref|Reynolds et al.|1987}}; {{AYref|Roth et al.|2001}}; {{AYref|Rushton|2000}}; {{AYref|Shuey|1958}}; {{AYref|Herrnstein and Murray|1994}}; {{AYref|Lynn|1991a}}. For samples of individual studies showing similar results, see the [http://www.archives.gov/research/electronic-records/nih.html National Collaborative Perinatal Project], reported by {{AYref|Broman et al.|1987}}; the [[Minnesota Transracial Adoption Study]] reported by {{AYref|Weinberg et al.|1992}}; also {{AYref|Lynn|1977a}}, {{AYref|Lynn|1977b}}, {{AYref|Lynn|1982}}, {{AYref|Lynn|1987}}, {{AYref|Lynn|1991a}}; {{AYref|Lynn et al.|1991}}; {{AYref|Lynn and Hampson|1986a}} {{AYref|Lynn and Hampson|1986b}}; {{AYref|Lynn et al.|1987a}}, {{AYref|Lynn et al.|1987b}}; {{AYref|Lynn et al.|1988}}; {{AYref|Lynn and Holmshaw|1990}}; {{AYref|Lynn and Shigehasa|1991}}; {{AYref|Montie and Fagan|1988}}; {{AYref|Rushton|1997}}; {{AYref|Rushton and Jensen|2003}}; {{AYref|Rushton et al.|2003}}; {{AYref|Notcutt|1950}}; {{AYref|Jensen|1993}}; {{AYref|Jensen and Reynolds|1982}}; {{AYref|Peoples et al.|1995}}. For scientific consensus statements see {{AYref|Gottfredson|1997a}} and {{AYref|Neisser et al.|1996}}. Similar clustering occurs with related variables, such as [[Achievement gap|school achievement]], [[reaction time]], and [[neuroscience and intelligence|brain size]], and the gap shows up before age 3 on most standardized tests after matching for variables such as maternal education. Other clustering: {{AYref|Thernstrom and Thernstrom|2003}}; {{AYref|Jensen|1993}}; {{AYref|Jensen and Whang|1994}}; {{AYref|Lynn and Holmshaw|1990}}; {{AYref|Lynn and Shigehasa|1991}}; {{AYref|Ho et al.|1980a}}, {{AYref|Ho et al.|1980b}}; {{AYref|Harvey_et_al.|1994}}; {{AYref|Rushton|1991}}. The East-Asian/White/Black difference in average IQ can be measured in very young children. For example, a one standard deviation gap is observed in Black and White 3-year olds matched for gender, birth order, and maternal education ({{AYref|Peoples et al.|1995}}). {{AYref|Lynn|1996}} found that by age 6 the average IQ of East Asian children is 107, 103 for White children and 89 for Black children. {{A(Y)ref|Broman et al.|1987}} found that the same trichotomy in brain size and IQ held at 4 months, 1 year, and 7 years of age. Most [[Variance|variation]] in IQ in the U.S. occurs within individual families, not between races. However, even small differences in average IQ at the group level might theoretically have large effects on social outcomes. For example, a randomly selected group of Americans with an average IQ of 103 had a [[poverty line|poverty rate]] 25% lower than a group with an average IQ of 100. Similar substantial correlations in high school drop-out rates, crime rates, and other outcomes have been measured.For this calculation, [[Richard Herrnstein|Herrnstein]] and [[Charles Murray|Murray]] alter the mean IQ (100) of the U.S. [[National Longitudinal Survey|National Longitudinal Survey of Youth]]'s population sample by randomly deleting individuals below an IQ of 103 until the population mean reaches 103. This calculation was conducted twice and averaged together to avoid error from the random selection.({{AYref|Herrnstein_and_Murray|1994}}, pp. 364-368) Discussed further in the section [[Race_and_intelligence#Within_societies|#Significance of group IQ differences #Within societies]]. Many hypotheses have been proposed to explain racial-ethnic group differences in IQ. Certain environmental factors, such as [[nutrition]], are thought to modulate IQ in childrenwhether or not this carries over to adulthood remains to be investigated, and other influences have been hypothesized, including education level, richness of the early home environment, and other social, cultural, or economic factors. The primary focus of the scientific debate is whether group IQ differences also reflect a genetic component. [[Hereditarianism]] hypothesizes that a genetic contribution to intelligence could include genes linked to neuron structure or function, [[neuroscience and intelligence|brain size]] or metabolism, or other physiological differences which could vary with biogeographic ancestry. The findings of this field are often thought to conflict with fundamental social philosophies, and have thus engendered a large controversy. Some of the researchers who publically argue for the partly genetic hypothesis have received grants from the [[Pioneer Fund]], which has been accused of [[racism]] by some scientists and the [[SPLC]]. Other scientists, such as [[Steven Pinker]], argue unnecessary fear of the implications of the science of human nature has led to large swaths of the intellectual landscape being reengineered to deny fundamental aspects of human nature. Media portrayal of the role of genetic and environmental factors in explaining individual and group differences in IQ was shown in a 1988 study to be misleading regarding mainstream expert opinion. Some critics examine the fairness and validity of cognitive testing and racial categorization, as well as the reliability of the studies and the motives of the authors, on both sides. Some critics fear the misuse of the research, question its [[utility]], and feel that comparing the intelligence of racial groups is itself [[ethics|unethical]]. For instance, the disparity in average IQ among racial groups is sometimes mistaken for the idea that all members of one race are more intelligent than all members of another, or that ranking group IQ averages from "high" to "low" implies a moral ranking of races from "good" to "bad" or an overall ranking of "superior" to "inferior". The conclusion that some racial groups have lower average IQ scores, and the hypothesis that a genetic component may be involved, have led to heated academic debates that have spilled over into the public sphere. {{Message_box| id =totallydisputed| backgroundcolor =Pink| image =Stop_hand.svg| heading =The [[Wikipedia:NPOV dispute|neutrality]] and [[Wikipedia:Accuracy dispute|factual accuracy]] of this article are disputed.| message = This tag is supported by 1 "con" editor and considered inappropriate by 1 "con" editor and 2 "pro" editors. Please see the relevant discussion on the [[:{{NAMESPACE}} talk:{{PAGENAME}}|talk page]].}}[[Category:Accuracy disputes]][[Category:NPOV disputes]] {{Race and intelligence vertical navbox}} == Background information == ===Race=== {{Main|Race}} | ''See also: [[Race and multilocus allele clusters]]'' Racial distinctions are generally made on the basis of skin color, facial features, inferred ancestry, national origin and self-identification. In an ongoing debate, some geneticists argue race is neither a meaningful concept nor a useful [[heuristic]] device,{{AYref|Wilson et al.|2001}}, {{AYref|Cooper et al.|2003}} and even that genetic differences between groups are biologically meaningless,{{AYref|Schwartz|2001}}, {{AYref|Stephens|2003}} on the basis of that more genetic variation exists within such races than between themIt is well established that within-population genetic diversity is greatest within Sub-Saharan Africa, and decreases with distance from Africa. One study estimates that only 6.3% of the total human genetic diversity is explained by race.[http://www.cbse.ucsc.edu/pdf_library/MeaningOfRace_Riese101005.pdf] This value is similar comparable to other reports which find that on average approximately 85% of genetic variation occurs within populations., and that racial traits overlap without discrete boundaries.{{AYref|Sternberg et al.|2005}}, {{AYref|Suzuki and Aronson|2005}}, {{AYref|Smedley and Smedley|2005}}, {{AYref|Helms et al.|2005}}, [http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-311X2004000300003&lng=es&nrm=iso]. Lewontin, for example argues that there is no biological basis for race on the basis of research indicating that more genetic variation exists within such races than between them {{AYref|Lewontin|1972}}. .. Some critics of race may not consider this a problem for race and intelligence inquiries. [[Jared Diamond]], who praises [[Cavalli-Sforza]]'s genetics research over the decades for "demolishing scientists' attempts to classify human populations into races in the same way that they classify birds and other species into races"({{AYref|Diamond|2000}}), also argues "in mental ability New Guineans are probably genetically superior to Westerners" due to that intelligence was likely selected for in hunter-gatherer [[New Guinea]] societies where the challenges were tribal warfare and food procurement, compared with high population density European civilizations where the major survival pressure was on genes for resisting [[epidemic]]s ([[Guns, Germs, and Steel|Diamond 1997/99]], p.21). Other geneticists, in contrast, argue self-identified ancestry corresponds nearly perfectly with genetically-inferred ancestry when enough genetic loci are examined, and that [[Race and multilocus allele clusters|in genetic cluster analysis]], the clusters that emerge correspond with the [[biogeographic ancestry]] on which racial groups are based.{{AYref|Risch et al.|2002}}, {{AYref|Tang et al.|2005}}, {{AYref|Rosenberg et al.|2005}}: "If enough markers are used... individuals can be partitioned into genetic clusters that match major geographic subdivisions of the globe". It is well known that many [[allele]]s vary in frequency across human populations. While most of this variation is [[Neutral theory of molecular evolution|selectively netural]] and has no obvious phenotypic effect, a significant portion of human genes do show evidence of changes recent natural selection, which have led to functional differences between populations. Five recent studies have shown that some genes involved in brain development and other neuronal functions have variants that have spread to high frequencies under selective pressure and now occur in different frequencies in different global populations.{{AYref|Mekel-Bobrov et al.|2005}}, {{AYref|Evans et al.|2005}}, {{AYref|Wang et al.|2005}}, {{AYref|Voight et al.|2006}}, {{AYref|Moehler et al.|2002}} (this gene is also tied to behavior, discussed [[#_note-32|above]]). See the NYTimes' [http://www.nytimes.com/2005/09/08/science/08cnd-brain.html "Researchers Say Human Brain Is Still Evolving"] (September 8, 2005), and [http://www.nytimes.com/2006/03/07/science/07evolve.html?_r=1&oref=slogin "Still Evolving, Human Genes Tell New Story"] (March 7, 2006) for discussion of Mekel-Bobrov et al. and Evans et al., and Voight et al. (Discussed [[Race_and_intelligence#_ref-brain_alleles_1|below]].) Worldwide, human populations are geographically bounded into five less than perfectly distinct continental areas: the Americas, Eurasia (including Europe, North Africa and West Asia), East Asia, Sub-Saharan Africa, and the Pacific Islands (including Australia). At least for subjects of biomedical research in the [[United States]], self-identified racials labels correspond to geographic regions of genetic ancestry, with only a small number of individuals showing genetic cluster membership different from their self-identified race/ethnicity.{{AYref|Tang et al.|2005}} People labeled ''[[Blacks]]'' have most of their ancestors from sub-Saharan Africa, ''[[Whites]]'' from Europe (and sometimes the Middle East and North Africa), and ''[[East Asia|East Asians]]'' from the north-western Pacific Rim. ''[[Hispanics]]'' form a genetically diverse group that includes many recent U.S. immigrants of mixed ancestry, and are more often called an [[ethnic group]]. The political, social and cultural structure of the United States is still weighted by race. It was only in the 1960s that racial discrimination became illegal in many areas of public and private life, including employment and housing, and some consider discrimination to remain prevalent. The national and state governments of the United States employ racial categorization in the census, law enforcement, and innumerable other ways. Many political organizations intend to represent the interests of specific racial groups. See the articles [[Race]] and [[Race (U.S. Census)]] for further discussion. ===Intelligence testing=== {{Main|Intelligence quotient}} [[Intelligence (trait)|Intelligence]] is most commonly measured using IQ tests. These tests are often geared to be good measures of the [[psychometric]] variable '''''[[general intelligence factor|g]]''''', and other tests that measure ''g'' (for example, the [[Armed Services Vocational Aptitude Battery|Armed Forces Qualifying Test]] and the [[SAT]]) also serve as measures of cognitive ability. All such tests are often called "intelligence tests," though the use of the term "intelligence" is itself controversial. It is clear, however, that performance in these tests accurately predicts performance in similar life tasks (typical college courses, for example). The correlation with many real-world results is lower. For example, while the correlation of IQ with job performance is strong, income is modestly correlated and accumulated [[wealth]] is only weakly correlated. The genetic transmission of wealth via IQ is near zero. As commonly used, "IQ test" denotes any test of cognitive ability, and "IQ" is used as shorthand for scores on tests of cognitive ability. Some critics question the validity of all IQ testing or claim that there are aspects of "intelligence" not reflected in IQ tests. Historically, criticisms of the validity of IQ testing focused primarily on questions of "test bias", which has many related meanings. Several conclusions about tests of cognitive ability are now largely accepted: * IQ scores measure many, but not all of the qualities that people mean by ''intelligent'' or ''smart'' (for example, IQ does not measure creativity, wisdom, or personality) * IQ scores are fairly stable over much of a person's life * IQ tests are predictive of school and job performance, to a degree that does not significantly vary by socio-economic or racial-ethnic background * For people living in the prevailing conditions of the developed world, cognitive ability is substantially [[heritability|heritable]], and while the impact of family environment on the IQ of children is substantial, after adolescence this effect becomes difficult to detect. See the articles [[Intelligence (trait)|Intelligence]], [[intelligence quotient|IQ]], and [[general intelligence factor]] for further discussion of the validity of these tests. ===The contemporary debate: results and interpretations=== The contemporary scholarly debate about race and intelligence involves both the relatively uncontroversial experimental '''results''' that indicate that average IQ test scores vary among racial groups, and the relatively more controversial '''interpretations''' of these IQ differences. In general, contemporary interpretations of the "IQ gap" can be divided into three broad categories: # '''"culture-only"''' or '''"environment-only"''' interpretations that posit overwhelmingly non-genetic causes (for example, [[Economic inequality|socioeconomic inequality]] or [[minority]] group membership) that differentially affect racial groups; and # '''"partly genetic"''' interpretations that posit an IQ gap between racial groups caused by approximately the same matrix of genetic and environmental forces that cause IQ differences among individuals of the same race. # '''"insufficient data"''': no meaningful interpretation can be made based on available evidence. === History === [[Image:Francis Galton 1850s.jpg|right|thumb|155px|Sir [[Francis Galton]] wrote on [[eugenics]] and [[psychometrics]] in the 19th C.]] ====1850s to World War II==== The scientific debate on the contribution of [[nature versus nurture]] to individual and group differences in intelligence can be traced to at least the mid-19th century{{AYref|Degler|1992}}; {{AYref|Loehlin et al.|1975}}. [[Charles Darwin]] wrote in his ''[[Descent of Man]]'' (VII, ''On the races of Man''): "[T]he various [human] races, when carefully compared and measured, differ much from each other—as in the texture of hair, the relative proportions of all parts of the body, the capacity of the lungs, the form and capacity of the skull, and even the convolutions of the brain. But it would be an endless task to specify the numerous points of difference. The races differ also in constitution, in acclimatization 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." [[Image:FranzBoas.jpg|thumb|140px|left|[[Anthropology|Anthropologist]] [[Franz Boas]] was a prominent 20th C. critic of claims that intelligence differed among races.]] The writings of Sir [[Francis Galton]], elaborating on the work of his cousin Darwin, spurred interest in the study of mental abilities, particularly as they relate to [[heredity]] and [[eugenics]]. The fact that there are differences in the brain sizes and brain structures of different racial and ethnic groups was well known and widely studied during the [[19th century]] and early [[20th century]].{{AYref|Broca|1873}}, {{AYref|Bean|1906}}, {{AYref|Mall|1909}}, {{AYref|Morton|1839}}, {{AYref|Pearl|1934}}, {{AYref|Vint|1934}} Average ethnic and racial group differences in IQ were first found due to the widespread use of standardized mental tests during [[World War I]]. Beginning in the [[1930s]], [[hereditarianism]] — the belief that [[genetics]] contribute to differences in intelligence among humans — began to fall out of favor, in part due to the advocacy of [[Franz Boas]], who in his 1938 edition of ''The Mind of Primitive Man'' wrote, "there is nothing at all that could be interpreted as suggesting any material difference in the mental capacity of the bulk of the Negro population as compared with the bulk of the White population."{{AYref|Boas|1938}} The hereditarian position was greatly weakened by Boas' finding that cranial vault size had increased significantly in the U.S. from one generation to the next, because racial differences in such characteristics had been among the strongest arguments for a genetic role. Inspired by the American eugenics movement, [[Nazi Germany]] implemented the [[T-4 Euthanasia Program]] in which roughly 200,000 mentally and physically disabled Germans were killed, and about 400,000 sterilized. ====Post WWII and modern times==== Due in part to the association of hereditarianism with [[Nazi Germany]], after the conclusion of [[World War II]] until the 1994 publication of ''[[The Bell Curve]]'', it became largely taboo to suggest that there were racial or ethnic differences in measures of intellectual or academic ability and even more taboo to suggest that they might involve a genetic component{{AYref|Garrett|1961}}; {{AYref|Lynn|2001}}, pp. 45–54. [[Image:Charles_Murray.gif|left|thumb|140px|[[Charles Murray (author)|Charles Murray]] (pictured) and [[Richard Herrnstein]] started the contemporary debate with ''[[The Bell Curve]]'' in [[1994]].]] In 1961, the psychologist [[Henry Garrett]] coined the term ''equalitarian dogma'' to describe the then politically fashionable view that there were no race differences in intelligence, or if there were, they were purely the result of environmental factors. Those who questioned these views often put their careers at risk{{AYref|Lynn|2001}} pp. 67–69. [[Image:Stephen_Jay_Gould.png|right|thumb|140px|In ''[[The Mismeasure of Man]]'', updated in [[1996]], [[Stephen Jay Gould]] criticized many aspects of IQ research.]] The contemporary scholarly debate on race and intelligence may be traced to [[Arthur Jensen]]'s [[1969]] publication in the ''Harvard Educational Review'' of "How Much Can We Boost IQ and School Achievement?"{{AYref|Jensen|1969}} In this paper, he wrote on some of the major issues that characterize the partly genetic hypothesis of racial IQ differences, and on compensatory educational programs. Reports on Jensen's article appeared in ''[[Time]]'', ''[[Newsweek]]'', ''[[Life]]'', ''[[U.S. News & World Report]]'', and ''[[The New York Times Magazine]]''. Press attention returned to the issue of race and intelligence in [[1994]] with the publication of ''[[The Bell Curve]]'', which included two chapters on the subject of racial difference in intelligence and related life outcomes. In response to ''The Bell Curve'', [[Stephen Jay Gould]] updated ''[[The Mismeasure of Man]]'' in [[1996]].{{AYref|Gould|1996}} Among other things, he criticized the IQ test as a measure of intelligence, citing what he perceived as inherent racial and social biases as well as systematic flaws in the testing process. The introduction of [[Race in biomedicine|biomedicine]] tailored to the genetics and disease patterns of specific racial groups is currently one of the factors adding to the complexity and controversy of debates on race and science{{AYref|Kohn|2006}}. In [[2006]], the scholarly debate continues on the question of "whether the cause of group differences in average IQ is purely social, economic, and cultural or whether genetic factors are also involved"{{AYref|Rushton and Jensen|2005a}}. == Public controversy == {{main|Race and intelligence (Public controversy)}} ===Media portrayal === {{Main|Race and intelligence (Media portrayal)}} A [[1987]] study found that media portrayal of intelligence-related topics, including race and intelligence research, was then misrepresentative of opinion among academics such as psychologists, sociologists, cognitive scientists, educators, and geneticists. Among those surveyed, 53% thought that the black-white gap was partially genetic and 17% thought that it was entirely environmental. Journalists and editors had the opposite opinion.{{AYref|Snyderman and Rothman|1988}}; Whether this still applies today is unknown. (See below: [[Race and intelligence#Expert opinion|Expert opinion]].) A [[2004]] study found widespread research misinterpretation regarding the study's specific focus, "stereotype threat."{{AYref|Sackett et al.|2004}} Introducing stereotype threat to a test-taking environment has been shown to increase the existing gap between Blacks or Whites in relation to Whites or Asians respectively, and has thus been offered as a potential contributor to the gap. However, 88% of accounts in the popular media, 91% in scientific journals, and 67% in psychology textbooks misinterpreted the findings as that eliminating the introduced stereotype threat eliminated the Black-White gap, when in fact the students had already been matched according to prior scores. The authors suggest the appeal of the misinterpreted findings may have been a factor, and that such research results in general may in this way be systemically more readily accepted. ===Utility of research and racism=== {{Main|Race and intelligence (Utility of research)}} One criticism of race and intelligence research, regardless of whether racial differences are genetic or not, questions its [[utility]]. It's been argued that society might actually be better off "with an untruth: that there is no good reason for this [racial] inequality, and therefore society is at fault and we must try harder."{{AYref|Glazer|1994}}. The position that knowledge of ''what is'' is dependent on statements of ''what is good'' has been criticized by microbiologist [[Bernard Davis]] as the "moralistic fallacy," an implied converse of the [[naturalistic fallacy]]({{AYref|Davis|1978}}). The latter refers to an effort to derive an ''ought'' directly from an ''is'' (for example, war is good because it's part of human nature) and the former refers to an effort to derive an ''is'' from an ''ought'' (for example, war is not part of human nature because it's bad). The [[Southern Poverty Law Center]] has stated: "Race science has potentially frightening consequences, as is evident not only from the horrors of Nazi Germany, but also from the troubled racial history of the United States. If white supremacist groups had their way, the United States would return to its dark days. In publication after publication, hate groups are using this "science" to legitimize racial hatred."[http://www.splcenter.org/intel/intelreport/article.jsp?pid=625] Some scientists, including [[W. D. Hamilton]], "...Might it be fair also to say that the champions of 'no difference' in race or sex, or intelligence ... are the guardians of a greater 'untruth' that allows people to live together in mutual harmony, implying that these critics really deserve to be praised as our protectors even when they are factually wrong? ... I think also it is roughly how the self-appointed guardians choose to present themselves - leaving aside, usually, the step of frankly admitting that they are promoting factual untruths when they know that they are." While these scientists may, he argues, be driven by personal social or political concerns, "it is harder for me to caste a man like [[J. Philippe Rushton|Philipe Rushton]], taking an example from the other side, in a similar light. ... Rushton has to be admitted to be promoting a segment of the pan-human chromosome that is very distantly situated from his own locus, Ontario, supporting a locus situated at the far end of Asia." Hamilton concludes: "Any human science not aiming for factual truth in human social matters is as inevitably doomed to bring costly accidents in the long run as would be an unfactual science of technology" ({{AYref|Hamilton & Dawkins|2002}}, [http://www.amazon.com/gp/reader/0198503369/?v=search-inside&keywords=racial%20intelligence pp. 332-334]) considered one of the greatest evolutionary theorists of the 20th century,[http://www.edge.org/3rd_culture/hamilton/hamilton_index.html Dawkins 2000] argue that suppressing race and intelligence research is actually more harmful than dealing with it honestly. [[Linda Gottfredson]] argues:
Lying about race differences in achievement is harmful because it foments mutual recrimination. Because the untruth insists that differences cannot be natural, they must be artificial, manmade, manufactured. Someone must be at fault. Someone must be refusing to do the right thing. It therefore sustains unwarranted, divisive, and ever-escalating mutual accusations of moral culpability, such as Whites are racist and Blacks are lazy.{{AYref|Gottfredson|2005b}}
[[Steven Pinker]] argues that opposition to racism is based on [[morality|moral]], not scientific assumptions, and is not vulnerable to being disproved by bioscientific advances. "The case against bigotry is not a factual claim that humans are biologically indistinguishable. It is a moral stance that condemns judging an individual according to the average traits of certain groups..."''[[The Blank Slate]]'' p. 145. Pinker suggests that intellectual life may not at present be prepared to deal with this area of inquiry{{AYref|Pinker|2005}}. Coming advances in [[genetics]] and [[genomics]] are expected to soon provide the ability to test hypotheses about group differences rigorously, whether between races, sexes, or other groups, in cognitive traits or temperament, musical or athletic talent, or in responses to biomedical treatments. Some scientists predict this will be the source of one of the biggest social and intellectual issues of the coming decades. {{AYref|Pinker|2006}} predicts "the dangerous idea of the next decade [will be] that groups of people may differ genetically in their average talents and temperaments . . . Perhaps geneticists will forbear performing these tests, but one shouldn't count on it. The tests could very well emerge as by-products of research in biomedicine, genealogy, and deep history which no one wants to stop." {{AYref|Stock|2002}} argues "We will have to consider how much our genes shape personality, intelligence, athletic talent, musical ability, memory, temperament, [and] sexual orientation [as] such sensitive issues will not remain in limbo much longer . . . The answers will be just another byproduct of [advances that allow us] to find useful correlations between our genes and key aspects of who we are. How we respond to this new information will be one of the biggest social and intellectual challenges of the coming decades, for we will learn a great deal about ourselves that many people would rather not face" (pp. 44-47, also p. 105). {{AYref|Murray|2005}} discusses the issue of group differences also in the context of age groups and sexual orientation groups. ===Accusations of bias=== {{main|Race and intelligence (Accusations of bias)}} The largest source of funding for proponents of the partly genetic interpretation, the [[Pioneer Fund]], has been criticized by some critics as having a [[eugenics|eugenic]] and [[racism|racist]] political agenda, and has been characterized by the controversial [[Southern Poverty Law Center]] as a "[[hate group]]," using the definition "attack[ing] or malign[ing] an entire class of people, typically for their immutable characteristics". http://www.tolerance.org/maps/hate/index.html. Other critics regard the fund as having had an ultimately positive effect. [[Ulric Neisser]], who was the chairman of the APA's [[Race_and_intelligence#Expert_opinion|1995 taskforce]] on intelligence research, gave support for [[Richard Lynn]]'s argument in Lynn's ''The Science of Human Diversity: A History of the Pioneer Fund'' (2001). Neisser states in his book review ({{AYref|Neisser|2004}}) that, though race and intelligence research "turns [his] stomach . . . Lynn's claim is exaggerated but not entirely without merit: 'Over those 60 years, the research funded by Pioneer has helped change the face of social science.'" Neisser concludes in agreement with Lynn and against [[William H. Tucker|William Tucker]]'s critical book on the Pioneer Fund ({{AYref|Tucker|2002}}), also reviewed, that the world is ultimately better off having had the Pioneer Fund: "Lynn reminds us that Pioneer has sometimes sponsored useful research - research that otherwise might not have been done at all. By that reckoning, I would give it a weak plus." Some critics have found it significant that some of the prominent researchers advancing genetic explanations have also opposed affirmative action and school integration.{{AYref|Tucker|2002}} [[Steven Pinker]] argues a fear of the implications of the science of human nature ("mind, brain, genes, and evolution") has led to the perception that these are dangerous ideas{{AYref|Pinker|2006}}. Pinker argues this has resulted in a denial of human nature in which "large swaths of the intellectual landscape have been reengineered to try to rule [...] hypotheses out [[a priori]] (race does not exist, intelligence does not exist, the mind is a blank slate inscribed by parents)." Scientists working in these areas have in the past been targets of censorship, violence, and comparisons to Nazis{{AYref|Pinker|2006}}, {{AYref|Tucker|2002}}. {{AYref|Gottfredson|2005a}} summarizes the history of harrassment and violence in this area: "For a long time Jensen received death threats, needed body guards while on his campus or others, had his home and office phones routed through the police station, received his mail only after a bomb squad examined it, was physically threatened or assaulted dozens of times by protesters disrupting his talks in the United States and abroad, regularly found messages like "Jensen Must Perish" and "Kill Jensen" scrawled across his office door, and much more. Psychologists [[Richard Herrnstein]] and [[Hans Eysenck]] also had such experiences during the 1970s for defying right thinking about intelligence—Eysenck, for example, being physically assaulted by protesters during a public lecture at the London School of Economics.". == Average test score gaps among races == {{main|Race and intelligence (Average gaps among races)}} [[Image:IQ-4races-rotate-highres.png|thumb|401px|Cumulative IQ gaps by race or ethnicity based on 1981 U.S. distributions. According to these findings, [[Wechsler Adult Intelligence Scale|WAIS]] IQs for Whites (mean = 101.4, SD = 14.7) were higher than those for Blacks (mean = 86.9, SD = 13.0); distributions for Hispanics (mean = 91), East Asians (mean = 106), and Ashkenazi Jews (mean = 112-115) are less precise because of overlap and small sample size. The modern debate focuses on what causes these disparities in average IQ. Based on {{AYref|Reynolds et al.|1987}}, p. 330.]] The modern controversy surrounding intelligence and race focuses on the results of IQ studies conducted during the second half of the 20th century, mainly in the United States and some other industrialized nations. In almost every testing situation where tests were administered and evaluated correctly, a difference of approximately one [[standard deviation]] was observed in the US between the mean IQ score of Blacks and Whites. Most attempted compilations of average IQ by race place [[Ashkenazi Jews]] at the top, followed by [[East Asia]]ns, [[White (people)|Whites]], [[Hispanic]]s and [[Native Americans]], [[African Americans]], [[Sub-Saharan Africa]]ns, and [[Indigenous Australians]].For example, see {{AYref|Herrnstein and Murray|1994}}; {{AYref|Lynn|1991a}}; {{AYref|Lynn|2006}}. Some other psychological traits, such as behavioral inhibition, have also been found to vary significantly in distribution among ethnicities{{AYref|Moehler et al.|2006}} finds significantly higher behavioral inhibition in German children with blonde hair, slightly higher inhibition in American children with blue eyes, and a statistically insignificant increase in inhibition in German children with blue eyes. {{AYref|Harpending and Cochran|2002}} discuss substantially different worldwide frequencies of a [[dopamine]] allele associated with [[Attention-deficit hyperactivity disorder|attention-deficit/hyperactivity disorder]] and novelty-seeking behavior, noting high frequencies in South American Indians, such as the [[Yanomamo]] (sometimes referred to as "the Fierce People"), intermediate frequencies in Europeans and Africans, and very low frequencies in East Asians and [[Bushmen|Kung! Bushmen]] (sometimes referred to as "the Harmless People")., but group differences in tests of cognitive ability have been the subject of more attention, as they're seen by some as one of society's most pressing problems{{AYref|Sackett et al.|2004}} p. 11. ===World-wide scores=== Cognitive ability scores for the ten global genetic clusters identified in previous genetic cluster analysis{{AYref|Cavalli-Sforza et al.|1994}} have been surveyed by [[Richard Lynn]]{{AYref|Lynn|2006}}. In general, Lynn lists East Asians and Europeans as demonstrating the highest average IQ, indigenous Americans and other Eurasians with intermediate average IQ, and Africans and Australian Aborigines with the lowest average IQ. Lynn's 2006 work on the subject is an expansion of the data in his earlier ''[[IQ and the Wealth of Nations]]'' with [[Tatu Vanhanen]], which received strong criticism for both error and alleged bias, but has also been used as a source of IQ data and hypotheses used in several peer-reviewed studies.Sociologist Thomas Volken argues the data for national IQs is "highly deficient," citing limited sampling and varying tests and years ([http://www.suz.unizh.ch/volken/ThomasVolken/pdfs/IQWealthNation.pdf Volken]). In a review of ''The Bell Curve'', controversial critic [[Leon Kamin]] writes that "Lynn's distortions and misrepresentations of the data constitute a truly venomous racism, combined with scandalous disregard for scientific objectivity."({{AYref|Kamin|1995}}). John M. Grohol comments of the data massaging by Lynn and Vanhanen: "In many cases arbitrary adjustments were made by authors to account for the Flynn effect or when the authors thought that the studies were not representative of the ethnic or social composition of the nation."[http://psychcentral.com/psypsych/IQ_and_the_Wealth_of_Nations] In contrast to Kamin's strongly worded attack on Lynn, [[W. D. Hamilton]] described Lynn in a review of another of Lynn's books as doing "an excellent job with the facts" and being "brave [and] thick-skinned ... to swim against ... popular antirealistic currents."[http://www.blackwell-synergy.com/doi/abs/10.1046/j.1469-1809.2000.6440363.x] Examples of problematic national IQ figures include that the stated average IQ score of 59 for Equatorial Guinea is based on one test of 48 children aged 10-14 in 1984; the Ethiopian average is derived from a study of Ethiopians who immigrated to Israel a year prior, and whose low scores were thought by the original authors to be a reflection of temporary adjustment to a different culture and language (note that this data is not used in the averages presented below). Kamin also argued Lynn selectively excluded data showing a similar score in Whites and sub-Saharan Africans: "Lynn chose to ignore the substance of Crawford-Nutt's paper, which reported that 228 black high school students in Soweto scored an average of 45 correct responses on the Matrices--HIGHER than the mean of 44 achieved by the same-age white sample on whom the test's norms had been established and well above the mean of Owen's coloured pupils." ({{AYref|Kamin|1995}}) IQ scores vary greatly among different nations for related groups. Blacks in Africa score much lower than Blacks in the US. Some reports indicate that the Black–White gap is smaller in the UK than in the U.S.{{AYref|Gene Expression|2003}}. American Blacks average about 7-20% European admixture{{AYref|Burchard et al.|2003}};{{AYref|Parra et al.|1998}}; UK admixtures are not as well-studied. Many studies also show differences in IQ between different groups of Whites. In Israel, large gaps in test scores and achievement separate [[Ashkenazi Jews]] from other groups such as the [[Sephardi]]{{AYref|Willms and Chen|1989}}. ===Brain size, employment tests, and school achievement=== IQ has a low to moderate correlation with various measures of brain size and performance on elementary tests of response time{{AYref|Neisser et al.|1996}}. For example, a [[2005]] meta-analysis found that brain size correlates with IQ by a factor of approximately .40 among adults. {{AYref|McDaniel|2005}} Reaction times correlate with IQ by about .30 to .50{{AYref|Grudnick and Kranzler|2001}}. Studies have shown racial differences in both brain sizesee {{AYref|Neisser|1997}}, p. 80 for a consensus statement and tests of response timesee [[Race and intelligence (Average gaps among races)#Reaction_time]]. Cranial vault size and shape have changed greatly during the last 150 years in the US. These changes must occur by early childhood because of the early development of the vault. The explanation for these changes may be related to the [[Flynn effect]]. {{AYref|Gravlee et al.|2003a}}, {{AYref|Gravlee et al.|2003b}}; {{AYref|Jantz and Jantz|2000}}, {{AYref|Jantz|2001}} Gaps are seen in other tests of cognitive ability or aptitude, including university admission exams such as the [[SAT]] and [[Graduate Record Examination|GRE]] as well as employment tests for corporate settings and the military{{AYref|Roth et al.|2001}}. Measures of school achievement correlate fairly well with IQ, especially in younger children. In the United States, achievement tests find that by 12th grade Black students are performing on average only as well as White and Asian students in 8th grade; Hispanic students do only slightly better than Blacks. Whether these gaps are narrowing or not is debated. == Cultural or genetic explanation? == [[Image:1995-SAT-Education.png|right|thumb|356px|Family social-economic variables (education shown) are positively correlated with IQ scores (SAT shown). However, the score gap between races persists at all socio-economic levels. These kinds of findings have led some to argue that that differences in [[socio-economic status]] cannot explain all the IQ gap.]] {{main|Race and intelligence (Culture-only or partially-genetic explanation)}} === Introduction === The most widely accepted view among intelligence researchers is that IQ differences among individuals of the same race reflect real, functionally/socially significant, and substantially genetic differences in the [[general intelligence factor]], ''g''. It is likewise widely believed that average IQ differences among races reflect real and significant differences in the same ''g'' factor.{{AYref|Gottfredson|2005b}}; {{AYref|Snyderman and Rothman|1987}}; {{AYref|Neisser et al.|1996}}; {{AYref|Gottfredson|1997a}} While these conclusions are largely beyond technical dispute, the nature of ''g'' is still an active area of research. However, it is a matter of debate whether IQ differences among races in the U.S. are entirely environmental or partly genetic. Several published consensus statements agree that the large difference between the average IQ scores of Blacks and Whites in the U.S. cannot be attributed to biases in test constructionSee for example {{AYref|Gottfredson|1997a}}, nor can they be explained by simple differences in socio-economic status. These results are further supported when the artificial black-white dichotomy is supplemented with statistics for other ethnicities. It should be noted that most research has been done in the US and a few other developed nations (see [[Race_and_intelligence#World-wide_scores|above]] for worldwide data). That research cannot directly be generalized to the world as a whole. Blacks in the US do not constitute a random sample of the original African population, and environmental conditions differ among nations. IQ tests done in developing countries are likely to have been affected by conditions associated with poverty that are common in the developing world, such as nutritional deficiencies and the impact of diseases (for example, HIV, anemia or chronic parasites) that may affect IQ test scores. The extent to which the IQ gap is caused by genetic or environmental factors is logically independent of the ability for intervention to reduce the gap. A genetic cause is not necessarily irremediable (e.g. [[diabetes]], [[myopia]], and [[phenylketonuria]]) and an environmental cause may not be remediable (e.g. accidents and some diseases). Based in part on this distinction, {{A(Y)ref|Murray and Herrnstein|1994}} argue that determining the extent to which genes or environment cause the IQ gap is unimportant.Murry and Herrnstein argue that it would not be good to learn that the gap were predominantly environmental nor bad to learn that the gap were predominantly genetic. Instead, they argue that that what matters is how hard the gap is to change. They argue that the history of attempts to reduce the gap through environmental intervention have produced no definitive, lasting results. As such, even if the gap were entirely environmental, we would be no closer to changing it. They also argue that knowing whether the gap is genetic or environmental should not affect how individuals treat one another. First, because individuals should be treated as individuals rather than as groups. Second, because the reality of the gap is independent of the cause of the gap (that is, it would make no difference to learn that the gap were "only" caused by the environmnet. === Cultural explanations === Regarding the IQ gaps in the U.S., it has also been suggested that [[African-American]] culture disfavors academic achievement and fosters an environment that is damaging to IQ{{AYref|Boykin|1994}}. Likewise, it is argued that the persistence of negative racial stereotypes reinforces this effect. John Ogbu has developed a hypothesis that the condition of being a "caste-like minority" affects motivation and achievement, depressing IQ{{AYref|Ogbu|1978}}; {{AYref|Ogbu|2003}}. See {{AYref|Jensen|1998b}}, pp. 511-512 for a critique of these arguments.. Similarly, it's suggested reduced performance from "stereotype threat" could be a contributing factor.{{AYref|Steele and Aronson|1995}} found that making race salient when taking a test of cognitive ability negatively affected high-ability African American students. They name this phenomenon stereotype threat. {{AYref|Sackett et al.|2004}} point out that these findings are widely misinterpreted to mean that eliminating stereotype threat eliminated the Black-White performance gap. See also {{AYref|Cohen and Sherman|2005}}, {{AYref|Helms|2005}}, {{AYref|Wicherts|2005}} and {{AYref|Sackett et al.|2005}} for discussion of the implications of stereotype threat for race and intelligence research. [[Image:James Flynn.jpg|left|thumb|140px|[[James R. Flynn]] discovered the [[Flynn effect]], that average IQ scores are increasing worldwide.]] Many anthropologists have argued that intelligence is a cultural category; some cultures emphasize speed and competition more than others, for example. Speculations about innate differences in group intelligence have a long history. [[Richard E. Nisbett|Richard Nisbett]] claims that Moors who invaded Europe in the [[Middle Ages]] thought the Europeans might be congenitally incapable of abstract thought.{{AYref|Nisbett|1998}} Even proponents of the view that the IQ gap is caused partly by genetic differences recognize that non-genetic factors are likely to be involved. In the developing world many factors can greatly decrease IQ scores. Examples include nutrition deficiencies in [[iodine]] and [[iron]]; certain diseases like [[malaria]]; unregulated toxic industrial substances like [[lead]] and [[mercury (element)|mercury]]; and poor health care for pregnant women and infants. Also in the developed world there are many non-genetic biological factors that can affect IQ. 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. Indeed, one author has compiled a list of over one hundred possible causes of the Black-White IQ gap.[http://personnelselection.com/adverse.impact.htm] See [[Race and intelligence (Culture-only or partially-genetic explanation)#Nongenetic biological factors]] The poorly understood [[Flynn effect]] is often cited as evidence that average IQ scores have changed greatly and rapidly, noting that average IQ in the US, after norming to today's standards, may have been below 75 before the start of this effect. 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 only occurred predominantly in the lower half of the IQ distribution{{AYref|Colom et al.|2005}}. Some therefore argue that the IQ gap among races might change in the future or is even now be changing. On the supposition that the effect started earlier for Whites, because their social and economical conditions began to improve earlier than did those of Blacks, they see even more promise in this hypothesis. However, after analyzing IQ data, one research group concluded 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 factor|general intelligence]] or higher-order ability factors, unlike the B-W IQ gap.({{AYref|Wicherts et al.|2004}}) A recent theory hypothesizes that fluid cognition (gF') may be separable from general intelligence, and that gF' may be very susceptible to environmental factors, in particular early childhood [[Stress (medicine)|stress]]. Some IQ tests, especially those used with children, are poor measures of gF', 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. [http://www.bbsonline.org/Preprints/Blair-04012003/Referees/] Many studies that attempt to test for heritability find results that do not support the genetic hypothesis. They include studies on IQ and skin color, self-reported European ancestry, children in post WWII Germany born to Black and White American soldiers, blood groups, and mixed-race children born to either a Black or a White mother. Many intervention and adoption studies also find results that do not support the genetic hypothesis. Non-hereditarians have argued that these are direct tests of the genetic hypothesis and of more value than indirect variables, such as skull size and reaction time.{{AYref|Nisbett|2005}}. Hereditarians argue that these studies are flawed, or that they do support the partly-genetic hypothesis. === Genetic explanations === [[Image:Jensen2.jpg|right|thumb|140px|The contemporary debate can be traced to psychologist [[Arthur Jensen]] in 1969.]] Arthur Jensen and others have concluded that the IQ gap is substantially genetic. Rushton and Jensen argue that while plausible environmental explanation for the lower mean IQ in Blacks in the U.S. can be offered in many cases, these explanations are less capable of explaining the higher average IQ of East Asians than Whites. Under their interpretation of [[Lakatos]]'s technical concept of [[Lakatos#Research programs|research programs]], Jensen and Rushton argue that the culture-only hypothesis is not "progressive" but "degenerating"{{AYref|Rushton and Jensen|2005a}}. To support these claims, they most often cite: #Black–White–East Asian differences in IQ, reaction time, and brain size, with Black-White IQ differences observable at age 3 in the U.S. There are also some studies done in developing nations supporting this, although very few regarding brain size and reaction time. #race differences are most pronounced on tests that are the best measures of ''g''For example, see {{AYref|Rushton and Jensen|2003}}(see [[Spearman's hypothesis]]), which also show the highest heritability and show the highest [[inbreeding depression]] scores{{AYref|Rushton|1989a}} #the rising [[IQ#Development|heritability of IQ]] with age (within races; on average 20% heritability in infants, 40% in middle childhood, and 80% in adulthood) and the disappearance (~0.0) by adulthood of shared environmental effects on IQ (for example, family income, education, and home environment), making adopted siblings no more similar in IQ than strangers{{AYref|Plomin et al.|2001}} #[[Regression toward the mean|regression]] to differing means for different races. For fuller listings of evidence for the partly-genetic position, see [[Race and intelligence (Culture-only or partially-genetic explanation)#Comparison of interpretations|Comparison of interpretations]], {{A(Y)ref|Rushton and Jensen|2005a}}, or [http://www.eurekalert.org/pub_releases/2005-04/cdri-bai042505.php this press release]. {{A(Y)ref|Rushton and Jensen|2005a}} have concluded that the best explanation is that 50%-80% of group difference is genetic.{{AYref|Rushton and Jensen|2005a}}, cited in "[http://www.eurekalert.org/pub_releases/2005-04/cdri-bai042505.php Black-White-East Asian IQ differences at least 50% genetic, scientists conclude in major law journal]", and {{AYref|Murray|2005}} Other evidence, such as [[Minnesota_Transracial_Adoption_Study|transracial adoption]], differing SAT scores even when matched for socioeconomic status and parental education, certain racial admixture studies, "life-history" traits, and evolutionary explanations have also been proposed to indicate a genetic contribution to the IQ gap. Critics of this view, such as [[Robert Sternberg]], argue that these studies are flawed and thus inconclusive or that they support the culture-only hypothesis. A 2001 study by Dolan and Hamaker reanalyzed the data from several earlier studies and concluded that Spearman's hypothesis is not an "empirically established fact". Five recent studies have shown that some genes involved in brain development and other neuronal functions have variants that have spread to high frequencies under selective pressure and now occur in different frequencies in different global populations. The novel variants of microcephalin and ASPM, genes previously implicated in the evolution of human brain size, were found at low frequencies in sub-Saharan African populations, at 70% and 50% in Europeans, 70% and less than 50% in East Asians, and microcephalin at 100% in the tested South American Indian populations. ASPM is estimated to have arisen 500-14,100 years ago, with the researchers favouring 5800. Different populations may utilize different variants to respond to similar evolutionary pressures. For a study on the biogeographic distribution of several genetic markers (not necessarily related to brain function), see: [http://www.scs.uiuc.edu/~mcdonald/WorldHaplogroupsMaps.pdf] and [https://www5.nationalgeographic.com/genographic/atlas.html] === Expert opinion === In a [[Race_and_intelligence_(Culture-only_or_partially-genetic_explanation)#Opinions_of_scholars_and_others|1987 survey]] of scholars in specialties related to IQ in Education, Psychology, Sociology, and Cognitive Science, given four choices, 52.9% of respondents supported the "partly genetic" position, 1.2% of respondents supported the "entirely genetic" position, 17.7% supported the "entirely environmental" position, and 28.2% responded that there was insufficient data "to support any reasonable opinion"{{AYref|Snyderman and Rothman|1987}}. Critics accept the results of this survey. [[Robert Sternberg]], for example, defends the minority view, stating "science isn't done by majority rule" (1995).[http://www.uclan.ac.uk/facs/science/psychol/Psychology/Skeptic.htm]. Respondents on average called themselves slightly left of center politically, but political and social opinions accounted for less than 10% of the variation in responses. According to the [[Race_and_intelligence#Collective Statements|APA 1995 task force report]], in contrast:
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 APA journal that published the statement, ''[[American Psychologist]]'', subsequently published eleven critical responses in January 1997, most arguing that the report failed to examine adequately the evidence for partly-genetic explanations. [[Charles Murray (author)|Charles Murray]], for instance, 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.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.[http://www.commentarymagazine.com/production/files/murray0905.html#_ednref50]
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.{{AYref|Pinker|2006}}, {{AYref|Stock|2002}} pp. 44-47. Researchers who believe that there is no significant genetic contribution to race differences in intelligence include {{AYref|Flynn|1980}}, {{AYref|Brody|1992}}, {{AYref|Neisser et al.|1996}}, {{AYref|Nisbett|1998}}, {{AYref|Mackintosh|1998}}, {{AYref|Jencks and Phillips|1998}}, and {{AYref|Fish|2002}}. Some scientists who emphasize cultural explanations do not necessarily exclude a small genetic influence. {{A(Y)ref|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 {{AYref|McGurk|1953}}, {{AYref|Garrett|1961}}, {{AYref|Shuey|1966}}, {{AYref|Shockley|1968}}, {{AYref|Eysenck|1971}}, {{AYref|Baker|1974}}, {{AYref|Loehlin et al.|1975}}, {{AYref|Vernon|1979}}, {{AYref|Lynn|1991a}}, {{AYref|Waldman et al.|1994}}, {{AYref|Scarr|1995}}, {{AYref|Levin|1997}}, {{AYref|Jensen|1998b}}, {{AYref|Rushton|2000}}, and {{AYref|Gottfredson|2005b}}. ==Significance of group IQ differences== :''See also: [[Intelligence_quotient#Practical_importance|Practical importance of IQ]]'' ===Within societies=== There is substantial overlap in the distribution of IQ scores among individuals of each race. {{A(Y)ref|Jensen|1998b}} (p. 357) estimates that in a random sample of equal numbers of US Blacks and Whites, most of variance in IQ would be unrelated to race or social class. The average IQ difference between two randomly paired people from the U.S. population, one Black and one White, is approximately 20 points. However, by the same method of calculation, the average difference between two random people is approximately 17 points, and the average difference between two siblings is 12 points. In essays accompanying the publication of ''[[The Bell Curve]]'', Herrnstein and Murray argue that whether the cause of the IQ gap is partly genetic or entirely environmental does not really matter because that knowledge alone would not help to eliminate the gap and that knowledge should not impact the way that individuals treat one another. They argue that group differences in intelligence ought not to be treated as more important or threatening than individual differences, but suggest that one legacy of Black slavery has been to exacerbate race relations such that Blacks and Whites cannot be comfortable with group differences in IQ or any other traits.{{AYref|Murray and Herrnstein|1994}}, {{AYref|Murray|2005}} Moreover, although it may appear paradoxical, a goal of social egalitarianism is to raise the genetic contribution to intelligence to as high as possible, by minimizing environmental inequalities and any negatively IQ-impacting cultural differences (''[[The Blank Slate]]'', 106-107). If such conditions were achieved, any remaining group IQ differences would then be 100% hereditary: the only remaining factor that could potentially contribute to race-based outcome differences. The appearance of a large practical importance for intelligence makes some scholars claim that the source and meaning of the IQ gap is a pressing social concern. The IQ gap is reflected by gaps in the academic, economic, and social factors correlated with IQ{{AYref|Gordon|1997}}; {{AYref|Gottfredson|1997b}}. However, some dispute the general importance of the role of IQ for real-world outcomes, especially for differences in accumulated [[wealth]] and general [[economic inequality]] in a nation. See "[[Intelligence_quotient#Practical_importance|Practical importance of IQ]]". Two statistical effects interact to exacerbate group IQ differences. First, there seem to be minimum statistical thresholds of IQ for many socially valued outcomes (for example, high school graduation and college admission). Second, because of the shape of the [[normal distribution]], only about 16% of the population is at least one standard deviation above the mean. Thus, although the IQ distributions for Blacks and Whites are largely overlapping, different IQ thresholds can have a significant impact on the proportion of Blacks and Whites above and below a particular cut-off. {| border="2" cellpadding="4" cellspacing="0" style="margin: 1em 1em 1em 0; border: 1px #aaa solid; border-collapse: collapse; font-size: 95%;" |+ '''Approximate IQ Distributions & Significance in the United States''' |- bgcolor=#ccccff !IQ range !Whites !Blacks !Black:White ratio !Training prospects !High school dropout !Lives in poverty !"Middle-Class Values" indexThe criteria for the "Middle-Class Values" index were: (for men) obtained high school degree (or more), were in labor force (but could be unemployed) throughout previous year (1989), never incarcerated, were still married to their first wife; (for women) obtained a high school degree, had never given birth out of wedlock, never incarcerated, were still marreid to their first husband. Individuals unable to work and those still in school were excluded from this analysis, as well as never-married individuals who satisfied all the other criteria. Poverty is not a criterion, nor is having children. |- bgcolor=E9E8FF | <75 || 3.6% || 18.0% || ~5:1 || simple, supervised work; eligible for government assistance || 55% || 30% || 16% |- bgcolor=#DFE0FF | 75-90 || 18.3% || 41.4% || ~2:1 || very explicit hands on training; IQ >80 for military training; no government assistance || 35% || 16% || 30% |- bgcolor=E9E8FF | 90-100 || 24.3% || 24.9% || ~1:1 || mastery learning, hands on || rowspan=2 | 6% || rowspan=2 | 6% || rowspan=2 | 50% |- bgcolor=E9E8FF | 100-110 || 25.9% || 11.9% || ~1:2 || written material plus experience |- bgcolor=#DFE0FF | 110-125 || 22.5% || 3.6% || ~1:6 || college format || 0.4% || 3% || 67% |- bgcolor=E9E8FF | >125 || 5.4% || 0.2% || ~1:32 || independent, self-teaching || 0% || 2% || 74% |- bgcolor=#DFE0FF | colspan="8" | Based on Wechsler Adult Intelligence Scale IQs for Whites (mean = 101.4, SD = 14.7) and for Blacks (mean = 86.9, SD = 13.0) from (Reynolds, Chastain, Kaufman, & McLean, 1987, p. 330). Significance data is from Herrnstein & Murray (1994), and is based on Whites only. Note that these are [[correlation]]s. For example, poverty could be both a cause and consequence of low IQ. |} Small differences in IQ, while relatively unimportant at the level of an individual, would theoretically have large effects at a population level. {{A(Y)ref|Herrnstein and Murray|1994}} calculate that a 3-point drop in average IQ would have little effect on factors like marriage, divorce, or unemployment. However, the drop from IQ 100 to 97 would increase poverty rates by 11 percent and the proportion of children living in poverty by 13 percent. All else being equal, similar rises would occur in rates of children born to single mothers, men in jail, high school drop-out, and men prevented from working due to health-related problems. In contrast, if average IQ were to increase 3-points to 103, poverty rates would fall 25 percent, children living in poverty would fall 20 percent, and high school drop-out rates would fall 28 percent. {| border="2" cellpadding="4" cellspacing="0" style="margin: 1em 1em 1em 0; background: #ccccff; border: 1px #aaa solid; border-collapse: collapse; font-size: 95%;" ALIGN="right" |+ '''Percentages of Blacks and Whites (Statistically Matched for IQ) in Educational and Social Outcomes''' |- bgcolor=#ccccff !Condition (matching IQ) !Blacks !Whites |- bgcolor=E9E8FF | High school graduation (103) || 91 || 89 |- bgcolor=#DFE0FF | College graduation (114) || 68 || 50 |- bgcolor=E9E8FF | High-level occupation (117) || 26 || 10 |- bgcolor=#DFE0FF | Living in poverty (100) || 14 || 6 |- bgcolor=E9E8FF | Unemployed for 1 month or more (100) || 15 || 11 |- bgcolor=#DFE0FF | Married by age 30 (100) || 58 || 79 |- bgcolor=E9E8FF | Unwed mother with children (100) || 51 || 10 |- bgcolor=#DFE0FF | Has ever been on welfare (100) || 30 || 12 |- bgcolor=E9E8FF | Mothers in poverty receiving welfare (100) || 74|| 56 |- bgcolor=#DFE0FF | Having a low birth-weight baby (100) || 6 || 3 |- bgcolor=E9E8FF | Average annual wage (100) || $25,001 || $25,546 |- bgcolor=#DFE0FF | "Middle-Class Values" index (100) || 48% || 32% |- bgcolor=E9E8FF | colspan="3" | from Herrnstein & Murray (1994), Chapter 14. |} Studies from ''[[The Bell Curve]]'' and elsewhere indicate that controlling for IQ narrows, eliminates, or even reverses the Black-White gap in social and economic factors associated with IQ. After controlling for IQ, the probability of having a college degree or working in a high-IQ occupation is higher for Blacks than Whites. Controlling for IQ shrinks the income gap from thousands to a few hundred dollars. Controlling for IQ cuts differential poverty by about three-quarters and unemployment differences by half. However, controlling for IQ has little effect on differential marriage rates. For many other factors, controlling for IQ eliminates the differences between Whites and Hispanics, but the Black-White gap remains (albeit smaller). Another study found that wealth, race and schooling are important to the inheritance of economic status, but IQ is not a major contributor and the genetic transmission of IQ is even less important.{{AYref|Bowles and Gintis|2002}}. Note that race, schooling and IQ are all correlated, so considering them as separate factors lessens the apparent effect of IQ. Whites are not a homogeneous group regarding real-world outcomes. For example, in the U.S. 33.6% of persons with self-reported Scottish ancestry has completed college, while only 16.7% of persons with self-reported French-Canadian ancestry have done so.these values were taken from {{AYref|Kangas|1999}}, which reprints U.S. Census data which was originally reported by {{AYref|Hacker|1995}}, p. 105. {{AYref|Drummond|2005}} challenges the factual accuracy of other reporting by {{AYref|Kangas|1999}}. For additional discussion of the effects of controlling for group differences on a variety of outcomes and groups, see {{AYref|Nyborg and Jensen|2001}}, and {{AYref|Kanazawa|2005}}. ===Between nations=== Differences in intelligence have been used to explain differences in economic growth between nations. One example is ''[[IQ and the Wealth of Nations]]''. The book, which received peer-review following publication, is sharply criticized in the peer-reviewed paper ''The Impact of National IQ on Income and Growth''. Thomas Volken, "[http://www.suz.unizh.ch/volken/ThomasVolken/pdfs/IQWealthNation.pdf The Impact of National IQ on Income and Growth]." Another peer-reviewed paper, ''Intelligence, Human Capital, and Economic Growth: An Extreme-Bounds Analysis'', finds a strong connection between intelligence and economic growth{{AYref|Jones and Schneider|2005}}. It has been argued that East Asian nations underachieve compared to IQ scores. One suggested explanation is that verbal IQ is more important than visuospatial IQ{{AYref|La Griffe du Lion|2004}}. [[Jared Diamond]]'s ''[[Guns, Germs and Steel]]'' instead argues that historical differences in economic and technological development for different areas can be explained by differences in geography (which affects factors like population density and spread of new technology) and differences in available crops and domesticatable animals.[[Richard E. Nisbett|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 Greece|ancient Greek]] herding, maritime mercantilism, and money crops wine and olive oil (pp. 34-35). However, these environmental differences may operate in part by [[natural selection|selecting]] for higher levels of IQThis theory is discussed by {{AYref|Jensen|1998b}} (pp. 435-437), {{AYref|Lynn|1991b}} and {{AYref|Rushton|2000}} in general and by [http://www.isteve.com/diamond.htm Steve Sailer] with respect to ''Guns, Germs, and Steel''. See [[Race and intelligence (Culture-only or partially-genetic explanation)#Rushton's application of r-K theory]]. .. {{AYref|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" ({{AYref|Kayser et al.|2003}}, {{AYref|Akey et al.|2004}}, {{AYref|Storz et al.|2004}}, {{AYref|Stajich and Hahn|2005}}, {{AYref|Carlson et al.|2005}}). ===For high-achieving minorities=== :''See also: [[Market dominant minority]]'' The book ''[[World on Fire]]'' notes the existence in many nations of minorities that have created and control a disproportionate share of the economy. Examples include Chinese in Southeast Asia; Whites, Indians, Lebanese and Igbo people of Western Africa; Whites in Latin America; and Jews in pre-World War II Europe, modern America, and modern Russia. These minorities are often resented and sometimes persecuted by the less successful majority. In the [[United States]], Jews, Japanese, and Chinese earn incomes 1.72, 1.32, and 1.12 times the American average, respectively (Sowell, 1981, p. 5). Jews and East Asians have higher rates of college attendance, greater educational attainment, and are many times overrepresented in the [[Ivy League]] and many of the United States' most prestigious schools{{AYref|Sowell|1981}}, pp. 7, 93, even though [[affirmative action]] discriminates against Asians in the admissions process (relative to Whites as well as to other minorities)A study by Princeton researchers {{AYref|Espanshade and Chung|2005}} analyzes the effects of admission preferences at elite universities in terms of [[SAT]] points (1600-point scale): Blacks +230; Hispanics +185; Asians −50; Recruited athletes +200; [[Legacy preferences|Legacies]] (children of alumni) +160. "Our results show that removing consideration of race would have a minimal effect on white applicants to elite universities. The number of accepted white students would increase by 2.4%." Asian percent of accepted students, in contrast, would increase by 33% (from 23.7% to 31.5%). "Nearly four out of every five places in the admitted class not taken by African-American and Hispanic students would be filled by Asians.". At [[Harvard]], for example, Asian American and Jewish students together make up 51% of the student body, though only constituting roughly 6% of the US population{{AYref|Hacker|2005}}. In various [[Southeast Asia]]n nations, Chinese control a majority of the wealth despite being a minority of the population and are resented by the majority, in some cases being the target of violence.{{AYref|Sowell|1981}}, pp. 133-134; {{AYref|Purdey|2002}} Achievement in science, a high-complexity occupation in which practitioners tend to have IQs well above average, also appears consistent with some group IQ disparity. Only 0.25% of the world population is Jewish, but Jews make up an estimated 28% of [[Nobel prize]] winners in physics, chemistry, medicine, and economics{{AYref|jinfo.org|2004}}. In the U.S., these numbers are 2% of the population and 40% of winners. A significant decline in the number of Nobel prizes awarded to Europeans, and a corresponding increase in the number of prizes awarded to US citizens, occurred at the same time as Nazi persecutions of Jews during the 1930s and the Holocaust during the 1940s{{AYref|Jank et al.|2004}}. Groups vary significantly in their IQ subtest profiles. Ashkenazi Jews, for example, demonstrate verbal and mathematical scores more than one standard deviation above average, but visuospatial scores roughly one half standard deviation lower than the White average{{AYref|Cochran et al.|2005}}, p. 4, whereas East Asians demonstrate high visuospatial scores, but average or slightly below average verbal scores.Lynn, [http://www.mugu.com/cgi-bin/Upstream/People/Lynn/lynn-race-iq-table2.html] [http://www.mugu.com/cgi-bin/Upstream/People/Lynn/lynn-race-iq-table2.html], {{AYref|Mackintosh|1998}}, p.178) Concordantly, the professions in which these populations tend to be over-represented differ {{AYref|Lynn|1991a}}. The Asian pattern of subtest scores is found in fully assimilated third-generation Asian Americans, as well as in Inuits and Native Americans (both of [[Human_migration#Earliest_migrations|Asian origin]]).{{AYref|Murray and Herrnstein|1994}} ==Policy implications== :''See also: [[Intelligence and public policy]]'' The public policy implications of IQ and race research are possibly the greatest source of controversy surrounding this issue. For example, the [[Conservatism|conservative]] policy recommendations of Herrnstein and [[Charles Murray (author)|Murray]] in ''[[The Bell Curve]]'' were denounced by many. Indeed, even proponents of a partly genetic interpretation of the IQ gap, such as {{A(Y)ref|Rushton and Jensen|2005a}} and {{A(Y)ref|Gottfredson|2005b}}, argue that their interpretation does not in itself demand any particular policy response: while a conservative/[[Libertarianism|libertarian]] commentator may feel the results justify reductions in [[affirmative action]], a [[Liberalism|liberal]] commentator may argue from a [[John Rawls|Rawlsian]] point of view (that genetic advantages are undeserved and unjust) for substantial affirmative action{{AYref|Gottfredson|2005b}}. According to the "Mainstream Science on Intelligence"; statement published in the ''Wall Street Journal'' in 1994:
The research findings neither dictate nor preclude any particular social policy, because they can never determine our goals. They can, however, help us estimate the likely success and side-effects of pursuing those goals via different means{{AYref|Gottfredson|1997a}}.
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 healthcare, 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 [[Intelligence and public policy#Health_and_Nutrition|health and nutrition policies relating to intelligence]]). Finally, [[germinal choice technology]] may one day be able to select or change directly [[allele]]s found to influence intelligence or racially identifying traits (such as skin color; see gene [[SLC24A5]]), making them susceptible to biotechnological intervention.[[Gregory Stock]] argues "current debates about whether some of the differences among ethnic and racial groups are cultural or biological will soon become irrelevant, given the coming [malleability of biological traits]" ({{AYref|Stock|2002}}, p. 194; race and intelligence discussed on pp. 44-47). ==End material== ===Notes===
=== See also === * [[Brain to body mass ratio]] * [[Craniometry]] * [[Hominid intelligence]] * [[Neuroscience and intelligence]] * [[Race and crime]] * [[Sex and intelligence]] * [[Scientific racism]] === References === {{main|Race and intelligence (References)}} === External links === ====Collective Statements==== * [http://www.psychpage.com/learning/library/intell/mainstream.html The Wall Street Journal: Mainstream Science on Intelligence][http://www.udel.edu/educ/gottfredson/reprints/1997mainstream.pdf PDF] * [http://www.lrainc.com/swtaboo/taboos/apa_01.html APA Task Force Examines the Knowns and Unknowns of Intelligence] * [http://www.aaanet.org/stmts/race.htm Statement on "Race" and Intelligence]. [[American Anthropological Association]]. Adopted December 1994. ====Review Papers==== * [http://www.udel.edu/educ/gottfredson/30years/ June 2005 issue of ''Psychology, Public Policy, and Law'', Vol. 11, No. 2.] ** [http://taxa.epi.umn.edu/~mbmiller/journals/pppl/200504/2/235-2.html Thirty Years of Research on Race Differences in Cognitive Ability] J. Philippe Rushton & Arthur R. Jensen ** [http://taxa.epi.umn.edu/~mbmiller/journals/pppl/200504/2/295-2.html There Are No Public-Policy Implications] Robert J. Sternberg ** [http://taxa.epi.umn.edu/~mbmiller/journals/pppl/200504/2/311-2.html What if the Hereditarian Hypothesis is True?] Linda S. Gottfredson ** [http://taxa.epi.umn.edu/~mbmiller/journals/pppl/200504/2/302-2.html Heredity, Environment, and Race Differences in IQ] Richard E. Nisbett ** [http://taxa.epi.umn.edu/~mbmiller/journals/pppl/200504/2/320-2.html The Cultural Malleability of Intelligence and Its Impact on the Racial/Ethnic Hierarchy] Lisa Suzuki & Joshua Aronson ** [http://taxa.epi.umn.edu/~mbmiller/journals/pppl/200504/2/328-2.html Wanted: More Race Realism, Less Moralistic Fallacy] J. Philippe Rushton & Arthur R. Jensen * [http://www-personal.umich.edu/~nisbett/racegen.pdf Race, Genetics and IQ] Richard E. Nisbett (PDF) * [http://www.commentarymagazine.com/production/files/murray0905.html The Inequality Taboo] Charles Murray * [http://brookings.nap.edu/books/0815746091/html/index.html The Black-White Test Score Gap (1998)] online (page-image) version of ISBN 0815746091 ====Others==== * [http://www.hirhome.com/rr/rrcontents.htm Resurrecting Racism: The modern attack on black people using phony science.] ''Historical and Investigative Research'' Francisco Gil-White 2005. * [http://www.opinionjournal.com/editorial/feature.html?id=110006608 Crippled by Their Culture - Race doesn't hold back America's black rednecks. Nor does racism] by [[Thomas Sowell]] * Race and IQ: [http://www.capmag.com/article.asp?ID=1958 Part 1], [http://www.townhall.com/opinion/columns/thomassowell/2002/10/02/164410.html Part 2], [http://capmag.com/article.asp?ID=1985 Part 3] by [[Thomas Sowell]] * [http://skepdic.com/iqrace.html The ''Skeptic's Dictionary'' entry on IQ and race] * [http://www.fair.org/index.php?page=1271 Criticism on source material of Bell Curve book] * [http://www.nccp.org/pub_pbd99.html Poverty and Brain Development in Early Childhood 1999 report] * [http://www.geocities.com/race_articles/ Miscellaneous articles] by [[Richard Lynn]] et al. *[http://www.psychpage.com/learning/library/intell/biased.html Are IQ Tests Biased?] *[http://www.ncrel.org/gap/library/text/scholarsprovide.htm Scholars Provide an Overview of Explanations for Black-White Test Score Gap] *[http://www.futureofchildren.org/pubs-info2825/pubs-info_show.htm?doc_id=255946 School Readiness: Closing Racial and Ethnic Gaps] * [http://theoccidentalquarterly.com/vol2no1/jpr-taxonomic.html Variation in IQ, Brain Capacity, Size and Density by Race] * [http://www.lagriffedulion.com La Griffe du Lion] - pseudonymously released statistical analyses on this and related subjects. ([http://www.vdare.com/sailer/zorro.htm Review]) * [http://jonjayray.tripod.com/knowledg.html Are all races equally intelligent? -- Or: When is knowledge knowledge?] by John J. Ray * [http://www.guardian.co.uk/science/story/0,3605,1687992,00.html A review of the field (Jan. 2006)] [[Marek Kohn|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]]''. *"[http://www.seedmagazine.com/news/2005/12/jews_on_jews_jews_are_great.php Jews on Jews: Jews are Great]," [http://www.seedmagazine.com Seed Magazine] {{Race and intelligence}} {{Race and sex differences}} [[fi:Rotu ja älykkyysosamäärä]]