[[Image:Sketch-4race-transparent2.png|thumb|400px|[[Normal distribution]] comparing [[race]]s and [[ethnic group]]s with [[IQ]] among U.S. test subjects from 1981 (the most recent, large-scale, published adult IQ scores). 'Asian' in the legend here refers to the [[US English]] usage of the word [[Asian]].[Based on {{AYref|Reynolds et al.|1987}} and [[# note-IQdistribution|others]]. The Black-White IQ gap shown in the figure is 14.5 points, which is 0.97 SD in size. The 1997 normalization of the U.S. military IQ test, the AFQT, also shows a gap of 0.97 SD, as reported by {{AYref|Murray|2005}}.] Whether the IQ gaps have narrowed since then and will continue to narrow or have remained consistent throughout the history of testing, and the causes and meaning of the different average scores for these groups are debated.[For example, {{AYref|Nisbett|2005}} argues, on the basis of shrinking gaps on achievement tests, that the B-W gap is "probably more like 0.6-0.7 standard deviation or approximately 10 IQ points," (2/3 of the gap shown here). Both {{AYref|Rushton and Jensen|2005b}} and {{AYref|Gottfredson|2005b}} argue that Nisbett is wrong, that "gains in scholastic achievement do not equal gains in ''g'', and the Black-White differences in ''g'' are as large as ever, even for measures of reaction time". More recently, {{AYref|Murray|2005}} has reviewed the results of both achievement and IQ tests and finds reason to believe that the Black-White gap in ''g'' may have shrunk from 1.2 sd to 1 sd. N.B. The US English meaning of the word [[Asian]] is being used here.]]]
'''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 two controversial assumptions:
*the social categories of [[race]] and [[ethnicity]] are [[concordance (genetics)|concordant]] with [[genetics|genetic]] categories, such as [[biogeographic ancestry]].
*[[Intelligence]] is quantitatively measurable (see [[psychometrics]]) by modern tests 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. There is much less data from other nations, in particular the developing world, and conclusions from the US data cannot automatically be generalized to the world as a whole. While the distributions of IQ scores among different racial-ethnic groups in the US overlap and often have a comparable [[Range (statistics)|range]], 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 has been reported with related variables, such as [[Achievement gap|school achievement]], [[reaction time]], and [[neuroscience and intelligence|brain size]].[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|Roth et al.|2001}}; {{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.[{{AYref|Jensen|1998}} reports on the distribution of IQ within and between families, social classes, and races using a technique to partition variance called [[ANOVA]]. The average IQ difference between two siblings (within families) is about 12 points, compared to 17 points for two strangers and 20 points for one White and one Black American. Jensen attributes the large differences within families to the high heritability of IQ and the small influence of family environment.] However, even small differences in average IQ at the group level might theoretically have large effects on social outcomes.
Several hypotheses have been proposed to explain why average IQ varies among racial-ethnic groups. Certain environmental factors, such as [[nutrition]], are thought to modulate IQ in children,[Whether 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 [[inheritance of intelligence|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 have engendered significant controversy. Media opinion of the role of genetic and environmental factors in explaining individual and group differences in IQ has itself been studied (1988) and found to differ from the opinion of mainstream experts.[{{AYref|Snyderman and Rothman|1988}}] Some critics question 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. This has included accusations of bias based on assumptions about the political ideals of the researchers or the funding agencies, such as the [[Pioneer Fund]]. Some critics fear the misuse of the research, question its [[utility]], or feel that comparing the intelligence of racial groups is itself [[ethics|unethical]]. The disparity in average IQ among racial groups does not mean that all members of one group are more intelligent than all members of another, nor that ranking group averages from "high" to "low" implies a moral ranking from "good" to "bad" or an overall ranking of "superior" to "inferior".[Researchers explicitly reject the latter terms as inaccurately global in connotation and insensitive, but the terms are used by some critics ({{AYref|Gordon|1997b}},[http://www.pioneerfund.org/Gordon.pdf] p. 42).] The conclusion that racial groups in the US vary in 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.
{{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 the United States. 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}} (given in {{AYref|Bamshad et al.|2004}}'s summary, p.599)] and even that genetic differences among groups are biologically meaningless,[{{AYref|Schwartz|2001}}, {{AYref|Stephens|2003}} (given in {{AYref|Bamshad et al.|2004}}'s summary, p. 599)] on the basis that more genetic variation exists within such races than among them,[It 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 comparable to other reports which find that on average approximately 85% of genetic variation occurs within populations. In a hypothetical situation with two populations and a single [[gene]] with two [[allele]]s, this is equivalent to allele frequencies of 30% + 70% in one population and 70% + 30% in the other. Thus, using this single gene to classify individuals into populations would result in a 30% misclassification rate.] 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). Concordant with this, a survey of cultural and physical anthropologists done in 1999[http://www.ssc.uwo.ca/psychology/faculty/rushtonpdfs/Lieberman2001CA.pdf] found that the concept of race was rejected by 69% of physical anthropologists and 80% of cultural anthropologists.
Other geneticists, in contrast, argue that categories of self-identified race/ethnicity or [[biogeographic ancestry]] are both valid and useful,[{{AYref|Risch et al.|2002}}, {{AYref|Bamshad|2005}}. [[Neil Risch]] argues: "One could make the same arguments about sex and age! . . you can undermine any definitional system. . . In a recent study. . . we actually had a higher discordance rate between self-reported sex and markers on the X chromosome [than] between genetic structure [based on microsatellite markers] versus [racial] self-description, [which had a] 99.9% concordance. . . So you could argue that sex is also a problematic category. And there are differences between sex and gender; self-identification may not be correlated with biology perfectly. And there is sexism. And you can talk about age the same way. A person's chronological age does not correspond perfectly with his biological age for a variety of reasons, both inherited and non-inherited. Perhaps just using someone's actual birth year is not a very good way of measuring age. Does that mean we should throw it out? . . . Any category you come up with is going to be imperfect, but that doesn't preclude you from using it or the fact that it has utility" ({{AYref|Gitschier|2005}}).] that these categories correspond with clusters [[Race and multilocus allele clusters|inferred from multilocus genetic data]],[{{AYref|Harpending and Rogers|2000}}, {{AYref|Bamshad et al.|2003}}, {{AYref|Edwards|2003}}, {{AYref|Bamshad et al.|2004}}, {{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".] and that this correspondence implies that genetic factors might contribute to unexplained phenotypic variation between groups.[{{AYref|Mountain and Risch|2004}}]
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).[{{AYref|Risch et al.|2002}}] At least in the [[United States]], self-identified racial 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, 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]].
It is well known that many [[allele]]s vary in frequency across (and within) human populations. Most of this variation is [[Neutral theory of molecular evolution|selectively neutral]], but a significant number show evidence of recent [[Natural selection#Directionality of selection|positive selection]].[According to a recent review by {{AYref|Sabeti et al.|2006}}, seven large-scale studies of positive selection in the human genome have been published. The "advantageous traits" that were being selected for are mostly unknown, but some make inferences based on the known functions of those genes in the regions that show signs of selection.] These include genes involved in brain development and other neuronal functions, which have variants that have spread to high frequencies under selective pressure and now occur in substantially different frequencies in different global populations.[{{AYref|Mekel-Bobrov et al.|2005}}, {{AYref|Evans et al.|2005}}, {{AYref|Voight et al.|2006}}, {{AYref|Wang et al.|2005}}, {{AYref|Harpending and Cochran|2002}}. The neural [[dopamine]] gene studied in Harpending and Cochran, previously found to occur in substantially different worldwide frequencies, is also tied to behavior, with bearers displaying greater novelty-seeking behavior and being at increased risk for [[attention-deficit hyperactivity disorder]]. Harpending and Cochran suggest this gene "may be a model system for understanding the relationship between genetic variation and human cultural diversity," 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"). ]
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. The actual functions of these genes, and their effect, if any, on IQ is unknown. (Discussed [[Race and intelligence# ref-brain alleles 1|below]].)
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}}
{{Further|[[Intelligence testing]], [[intelligence quotient]], [[general intelligence factor]]}}
[[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]]''''' (for ''general intelligence factor''), 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 correlates with performance in similar life tasks (school grades and to a lower degree college grades). 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 hereditary 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 by intelligence researchers:[For statements directly reporting what views are in the majority see {{AYref|Neisser et al.|1996}}, {{AYref|Gottfredson|1997a}}, and {{AYref|Snyderman and Rothman|1987}}. These findings are also discussed in the major handbooks, manuals, and encyclopedias on intelligence. For more detail, see the articles on [[IQ]] and [[intelligence]].]
* 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.
===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"''' (<20% genetic) interpretations that posit overwhelmingly non-genetic causes (for example, [[Economic inequality|socioeconomic inequality]] or [[minority]] group membership) that differentially affect racial groups;
# '''"partly genetic"''' (20-80% 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 opinion that there are differences in the brain sizes and brain structures of different racial and ethnic groups was widely held and studied during the 19th 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]].
Foremost amongst those researching this was [[Stanley Porteus]] of the [[University of Melbourne]], who devised his [[Porteus Maze Test|maze test]] as early as 1919, applying it in his study of the [[Indigenous Australians|Aborigines]] in the [[Kimberley region of Western Australia|Kimberley]] region and [[Northern Territory]] of Australia (1929) and later the [[Kalahari]] tribesmen of southern Africa (1934). He also used it to assess the results of pre-frontal brain surgery on mental performance, publishing his results in 1931.[Porteus, Stanley. ''The Psychology of a Primitive People'', 1931.]
Beginning in the 1930s, race difference research and [[hereditarianism]] — the belief that [[genetics]] contribute to differences in intelligence among humans — began to fall out of favor in psychology and anthropology after major internal debates.[According to historian of psychology Graham Richards there was widespread critical debate within psychology about the conceptual underpinnings of this early race difference research ({{AYref|Richards|1997}}). These include Estabrooks (1928) two papers on the limitations of methodology used in the research; Dearborn and Long’s (1934) overview of the criticisms by several psychologists (Garth, Thompson, Peterson, Pinter, Herskovits, Daniel, Price, Wilkerson, Freeman, Rosenthal and C.E. Smith) in a collection they edited and Klineburg, who wrote three major critiques, one in 1928, and two in 1935. Richards also notes that with over a 1000 publications within psychology during the interwar years there had been a large internal debate. Towards the end of the time period almost all those publishing, including most of those who began with a pro-race differences stance, were firmly arguing against race differences research. Richards regards the scientific controversy to be dead at this point, although he also suggests reasons for its re-emergence in the late nineteen sixties.] In anthropology this occurred 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 challenged by Boas' claim 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.
====Post WWII and modern times====
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. 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 (20-80% genetic) 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]]''.
In the 1980's Nobel Prize winner for his work on the development of transistors, [[William Shockley]], postulated that the higher rate of reproduction among US African Americans was having what he termed a "[[dysgenic]]" effect (meaning an opposite of [[eugenics]]), ; especially as influenced by welfare subsidies (e.g., [[AFDC]]), which he opined, unintentionally encouraged childbearing by less productive mothers. [George Bush: The Unauthorized Biography by Webster Griffin Tarpley and Anton Chaitkin, 1992 Executive Intelligence Review, Chapter 11]. He described this work as the most important work of his career, even though it severely tarnished his reputation. Shockley's published writings on this topic, were largely based on the research of [[Cyril Burt]]. Shockley also proposed that individuals with IQs below 100 be paid to undergo voluntary sterilization [George Bush: The Unauthorized Biography by Webster Griffin Tarpley and Anton Chaitkin, 1992 Executive Intelligence Review, Chapter 11]. He was subsequently criticized by the media; however his involvement brought public recognition to several controversial topics. [{{This paragraph includes excerpts from [[William Shockley]]; however editors of this page have expressed concern over the lack of citations at that article. A request for citation has been placed there. Please refer to discussion page before further editing etc}}]
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}}] 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}}]
== Average gaps among races in the US ==
{{main|Race and intelligence (Average gaps among races)}}
[[Image:US Europe Minorities IQ shuttergraph.png|thumb|300px|Average IQ scores of minority groups from North American and Europe, excluding East Asians. No dates given for individual measurements.[Average IQ score plotted for each group. The normalization average of 100 is shown as a dotted line. Dozens of individual studies are represented. Data taken from review by {{AYref|Lynn|2006}}.]]]
[[Image:East_Asians_IQ_year_scatter.png|thumb|300px|Average IQ scores of East Asians living in North American and East Asia. [Average IQ score and year of publication are plotted for each group. The normalization average of 100 is shown as a dotted line. Dozens of individual studies are represented. Data taken from review by {{AYref|Lynn|2006}}.]]]
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. On average, a difference of approximately one [[standard deviation]] was observed in previous studies in the US between the mean IQ score of Blacks and Whites. Most recent 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 in the United States|Native Americans]], and [[African Americans]].[For example, see {{AYref|Herrnstein and Murray|1994}}; {{AYref|Lynn|1991a}}; {{AYref|Lynn|2006}}] Whether these gaps have narrowed or not is debated.[For example, {{AYref|Nisbett|2005}} argues, on the basis of shrinking gaps on achievement tests, that the gap is "probably more like 0.6-0.7 standard deviation or approximately 10 IQ points." Both {{AYref|Rushton and Jensen|2005b}} and {{AYref|Gottfredson|2005b}} argue that Nisbett is wrong, that "gains in scholastic achievement do not equal gains in ''g'', and the Black-White differences in ''g'' are as large as ever, even for measures of reaction time". More recently, {{AYref|Murray|2005}} has reviewed the results of both achievement and IQ tests and finds reason to believe that the Black-White gap in ''g'' may have shrunk from 1.2 sd to 1 sd.]
Over the years, there has been variation in both the observed average IQ of groups, as well as the relative relationships between the average IQ of groups. Early 20th century measures typically found Blacks on the low end, and Whites on the high end. Based on studies from the 1960s and 1970s, Flynn found a slightly lower average IQ of Japanese- and Chinese American children compared to White counterparts.[In more than a dozen studies from the 1960s and 1970s analyzed by Flynn (1991, 2002), the mean IQs of Japanese- and Chinese American children were always around 97 or 98; none was over 100. These studies did not include other Asian groups such as the Vietnamese, Cambodians, or Filipinos; who tend to under perform academically and on conventional psychometric tests (See Flynn, 1991).] Recent contemporary measures place Blacks on the low end, and Asians on the high end. [{{AYref|Lynn|1982}} had reported that Japanese IQ was significantly higher than average IQ in the United States, and that Japanese IQ scores had risen over the past generation. {{AYref|Herrnstein and Murray|1994}}, {{AYref|Rushton and Jensen|2005}}, {{AYref|Lynn|2006}} find that the average IQ scores of East Asians in Asia, North America and Europe are signficantly higher than 100.]
===Employment tests and school achievement===
[[Image:GRE_by_race.png|right|thumb|300px|2001-2002 [[Graduate Record Examination|GRE]] scores - used in U.S. graduate schools - by race and ethnicity.[Published by the Graduate Record Examinations Board, (table A.2).[http://ftp.ets.org/pub/gre/994950.pdf]]]]
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.[{{AYref|Thernstrom and Thernstrom|2003}}]
There is wide agreement that [[achievement gap|the U.S. Black-White gap among children and adolescents on achievement tests]] narrowed in the 1970s and 1980s, but stalled during the 1990s.[{{AYref|Gottfredson|2005b}}, {{AYref|Murray|2006}}] On the basis of these data, {{AYref|Nisbett|2005}} argues that the gap in ''g'' has also narrowed. Both {{AYref|Rushton and Jensen|2005b}} and {{AYref|Gottfredson|2005b}} argue that "gains in scholastic achievement do not equal gains in ''g''". From the 1990s to 2005, Charles Murray argue that the U.S. Black-White gap on the SAT has increased in size to 1 SD.[see {{AYref|Murray|2006}}]
===U.S. Black-White gap===
There is disagreement about whether the results of IQ tests show a narrowing of the IQ gap, or if they do who has benefited. {{AYref|Rushton and Jensen|2005b}} and {{AYref|Gottfredson|2005b}} argue that "the Black-White differences in ''g'' are as large as ever". {{AYref|Roth et al.|2001}} found that the recent U.S. Black-White gap in ''g'' among adults is 1.1 sd, similar to characterization of the historical U.S. Black-White gap. In an analysis of standardization samples for the WAIS, WISC, SB, and AFQT, {{AYref|Dickens and Flynn|2006a}} find evidence that the U.S. Black-White gap shrunk between 3 and 6 points from 1972 to 2002. These conclusions were challenged by {{AYref|Rushton and Jensen|2006}}, and a rejoinder was made by {{AYref|Dickens and Flynn|2006b}}. Subsequently, {{AYref|Murray|2006}} analyzed testing data from the children of the 1979 NLSY cohort, concluding that "the B-W difference did not diminish on either academic achievement or cognitive tests for children born from the mid 1970s through the mid 1990s." To reconcile the contradictory findings, Murray suggests that "the effect that Dickens and Flynn found was concentrated among subjects born before the late 1970s". In 2006, Flynn and Murray debated the shrinking Black-White IQ gap. Both agree that the gap shrunk for children born before the late 1970s, however Murray believes the narrowing stopped while Flynn believes it has continued.[{{AYref|Flynn and Murray|2006}} put a link here.]
Several sources have argued that the U.S. Black-White gap varies with age. {{AYref|Dickens and Flynn|2006b}} estimate that the 2006 U.S. Black-White IQ gap is 0.31 SDs at age 4, 0.63 SDs at age 12, 0.87 SDs at age 18, and 1.1 SDs at age 24. Using data from {{AYref|Shuey|1966}}, {{AYref|Jensen|1998}} estimates that the U.S. Black-White gap is 0.70 SDs in early childhood, 1.00 SDs in middle childhood, and 1.20 SDs in early adulthood. A study of children aged eight to twelve months found a U.S. Black-White gap of 0.06 SD.[[http://post.economics.harvard.edu/faculty/fryer/papers/fryer_levitt_ecls_babies.pdf]]
===World-wide scores===
The largest review of the global cognitive ability data is [[Richard Lynn]]'s 2006 ''[[Race Differences in Intelligence]]'' (published by a non-academic publisher criticzed for publishing anti-semitic literature [http://www.searchlightmagazine.com/index.php?link=template&story=162]), which organizes the data by nine global regions,[Lynn derives these groups from global genetic branches identified in previous genetic cluster analysis ({{AYref|Cavalli-Sforza et al.|1994}} p. 79).] surveying 620 published studies from around the world, with a total of 813,778 tested individuals. Lynn's meta-analysis lists [[East Asia]]ns (105), [[Europeans]] (99), [[Inuit]] (91), [[Southeast Asia]]ns and [[Indigenous peoples of the Americas|Amerindians]] each (87), [[Pacific Islands|Pacific Islanders]] (85), [[Middle East]]erners (including [[South Asia]]ns and [[North Africa]]ns) (84), [[sub-Saharan Africa]]ns (67), and [[Indigenous Australians|Australian Aborigines]] (62). [[Searchlight magazine]] criticizes Lynn's publisher, which is not an academic press.[http://www.searchlightmagazine.com/index.php?link=template&story=162]]. Lynn has previously argued at length that nutrition is the best supported environmental explanation for variation in the lower range,[In ''RDiI'' Lynn surveys NGO reports of four different signs of severe malnutrition - underweight, anemia, wasting, and stunting - for five developing regions, ranking Latin America as suffering the least malnutrition, followed by the Middle-east, Asia/Pacific, Africa, and finally South Asia, suffering the worst malnutrition of any region (ch. 14).] and a number of other environmental explanations have been advanced (see [[Race and intelligence#Cultural or genetic explanations.3F|below]]). [[Ashkenazi Jews]] score significantly higher than other groups (107-115) in the U.S. and Britain, but estimates of the average IQ of Ashkenazim in [[Israel]] may be somewhat closer to the European mean.[Lynn's data is somewhat weak on Ashkenazi Jews ({{AYref|Malloy|2006}}), and only allows an indirect, weighted estimate in Israel (103), compared with (similarly indirect) estimates of 91 for Israeli Oriental Jews, and 86 for Israeli Arabs. Israeli Ashkenazi's scores may average lower than U.S. and British Ashkenazi, Lynn suggests, due to selective migration effects in relation to those countries, and to immigrants from the former Soviet Block countries having posed as Ashkenazim. The data isn't necessarily strong enough, however, to rule out identical scores for Ashkenazi across these nations ({{AYref|Malloy|2006}}).] In other data, [[Hispanics]] average 91 and [[African Americans]] average 87,[{{AYref|Reynolds et al.|1987}}.] though the latter is debated.[Sociologist Thomas Volken argues the ''IQ and the Wealth of Nations'' 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 1995 review of ''The Bell Curve'', 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}}). 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 in ''IQatWoN'' 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 above). 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}}).
{{AYref|Loehlin|2006}}'s checking of ''RDiI'''s data finds discrepancies that are "mostly minor. . . typically within a couple of IQ points" but concludes: "The citations and references were, on the whole, accurate. In short: Yes, the general trends in the tables are probably dependable, if the assumptions regarding Flynn effects, etc., are correct, but it is prudent (as always) to check with original sources before quoting particular results. . . Is this book the final word on race differences in intelligence? Of course not. But Richard Lynn is a major player, and it is good to have his extensive work on this topic together in one place. Future workers who address these matters under this or any other label will find that Lynn has done a lot of spadework for them..." Lynn argues the surveyed studies have high ''[[Reliability (statistics)|reliability]]'' in the sense that different studies give similar results, and high ''[[Validity (statistics)|validity]]'' in the sense that they correlate highly with performance in international studies of achievement in mathematics and science and with national economic development. In these studies European or "whites" in America and Europe are not separated into different categories (darker traited/lighter traited) and are averaged together as a whole. East Asians and other orientals are not averaged together. This is true in IQ tests and brain size studies.
Related groups sometimes vary greatly in IQ in different nations. Black Africans score much lower than blacks in the US, although Black Americans average about 7-20% European admixture.[{{AYref|Burchard ''et al.''|2003}};{{AYref|Parra ''et al.''|1998}}] Some reports indicate that the black–white gap is smaller in the UK than in the U.S.[{{AYref|Gene Expression|2003}}] Differences between groups of whites can also be seen, ranging to the low 90s in SE Europe (with a decrease also seen in brain size).[Lynn's ''[[Race Differences in Intelligence]]'', 2006.] 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 and reaction time===
There are several hotly debated studies which have concluded that there are race-based differences in brain size. These studies are criticized as having found no genetically ''racially''-based difference, with critics arguing instead the the variation correlates much better in terms of geography and environment.[{{AYref|Neisser|1997}}][ Perhaps the largest single study, by {{AYref|Beals et al.|1984}} which analyzed more than 20,00 skulls from around the world, found that brain size varied with latitude of biogeographic ancestry. Lieberman (2001) explains "...the relationship between latitude and cranial size is an example of Bergmann’s principle that crania are more spherical in cold climates because mass increases relative to surface area to conserve core temperatures...Beals, Smith, and Dodd emphasize that this relationship is independent of 'race'.".][ see http://www.ssc.uwo.ca/psychology/faculty/rushtonpdfs/Lieberman2001CA.pdf especially references to the work of Beals et al, 1984]. By this they mean that brain size varies with latitude both within and between races. The biogeographical variation in brain size is widely described as an evolutionary adaptation to climate.
Many studies report that IQ has a moderate correlation with various measures of brain size.[{{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}}; see also {{AYref|Bartley et al.|1997}}; {{AYref|Pennington et al.|2000}}; {{AYref|Posthuma et al.|2002}}; {{AYref|Rushton and Osborne|1995}}; {{AYref|Thompson et al.|2001}}] The correlation was also found in some studies to hold true within families (where environmental factors can be considered to be similar),[{{AYref|Gignac et al.|2003}}; {{AYref|Jensen|1994}}; {{AYref|Jensen and Johnson|1994}}] but in one study of 36 sibling pairs essentially zero correlation between brain size and IQ was found when comparing within families.[http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=18335] Some studies have found racial differences in brain size.[see {{AYref|Neisser|1997}}, p. 80] Professor [[Ulric Neisser]] claims that the studies comparing brain size by race "exhibit many internal inconsistencies", but that "there is indeed a small overall trend"[In his opinion, , but "such a trend hardly constitutes evidence for a genetic interpretation." See the explanations section for further detail ({{AYref|Neisser|1997}}). "[http://socrates.berkeley.edu/~maccoun/PP279_Neisser2.html Never a Dull Moment]" by [[Ulric Neisser]]].
A meta-analysis found that reaction times correlates with IQ by about .30 to .50.[{{AYref|Grudnik and Kranzler|2001}}] Average racial differences have been found on tests of response time, although it is also argued that some of these differences can be explained by cultural phenomena.[see [[Race and intelligence (Average gaps among races)#Reaction time]]] Reaction time also correlates with brain volume at approximately .4.[{{AYref|Wickett et al.|2000}}]
It is argued by some scientists that the combination of these correlations, of race to brain size, of brain size to reaction time, and of reaction time to IQ establishes a correlation between race and IQ. This conclusion is strongly objected to by other scientists, both on the basis of the initial correlation asserted between race and brain size, and the progressively weak correlation as the studies are combined.[
== Explanations ==
[[Image:TBC-BW-IQ-SES-withDiff.png|right|thumb|356px|Within individual countries, family social-economic variables are positively correlated with IQ scores. However, the black-white score gap persists at all socio-economic levels. These kinds of findings suggest that simple differences in [[socio-economic status]] cannot explain all of the IQ gap][Reviewed in {{AYref|Neisser et al.|1996}}. Data from the [[National Longitudinal Surveys|NLSY]] reported in {{AYref|Herrnstein and Murray|1994}}.].]]
{{main|Race and intelligence (Explanations)}}
=== Introduction ===
Most intelligence researchers believe that IQ differences among '''individuals''' reflect the [[general intelligence factor]], ''g''.[{{AYref|Gottfredson|2005b}}; {{AYref|Snyderman and Rothman|1987}}; {{AYref|Neisser et al.|1996}}; {{AYref|Gottfredson|1997a}}] The nature of ''g'' itself is still an active area of research, and the question of whether IQ differences among '''groups''' are substantially genetic is hotly contested.
According to the American Psychological Association, the difference between the average IQ scores of Blacks and Whites in the U.S. cannot be attributed to any obvious biases in test construction or cultural biases, as opposed to more occult environmental or genetic causes.[See for example APA's summary of their 1996 task force report ({{AYref|Neisser et al.|1996}}): "The differential between the mean intelligence test scores of Blacks and Whites does not result from any obvious biases in test construction and administration, nor does it simply reflect differences in socio-economic status" (Neisser et al. 1996); also: "It is clear, however, that these differences, whatever their origin, are well within the range of effect sizes that can be produced by environmental factors."(Neisser et al. 1996). The {{AYref|Gottfredson|1997a}} collective statement likewise states: "Intelligence tests are not culturally biased against American Blacks or other native-born, English-speaking people in the U.S. Rather, IQ scores predict equally accurately for all such Americans, regardless of race or social class."] Evidence against test construction and cultural bias includes the internal consistency of item difficulty for all groups, the equivalent validity of tests in predicting academic and occupational outcomes for all groups, and the persistence of the IQ gap on relatively culture-free tests.[{{AYref|Jensen|1980}}]
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). It is argued that because of the limited scope of research, that any conclusions cannot be directly generalized to the world as a whole.{{cn}} 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 have been known to affect IQ test scores.[reviewed by {{AYref|Lynn|2006}}]
Although IQ differences between individuals is highly heritable, this does not mean that average IQ differences between racial groups are necessarily genetic in origin, because estimates of heritability depend on the range of environments tested[{{AYref|Herrnstein and Murray|1994}}, {{AYref|Murray|2005}}]. High heritability by itself is not informative about group differences, so any inferences made from within group heritability will depend on additional considerations.[{{AYref|Jensen|1998}}] However, many scholars agree that no considerations of heritabilty are sufficient if group differences are caused by environmental factors that uniquely affect all members of one group but not another[{{AYref|Jensen|1998}} refers to such environmental factors as "Factor X", a name which he also applies to environmentalist hypotheses about group differences that posit the existence of a "Factor X". If group differences were caused by racism, then racism would be a "Factor X". {{AYref|Rowe et al.|1994}} and a number of subsequent studies sought and failed to find evidence for the existence of a Factor X. However, {{AYref|Gottfredson|2005}} warns that these studies are not "well replicated".].
=== Environmental explanations ===
{{Cleanup|October 2006}}
Arguing that IQ tests are often wrongly described as measuring "innate" rather than developed ability, {{AYref|Jencks and Phillips|1998}} conclude that this "labeling bias" causes people to inappropriately attribute the Black-White gap to "innate" differences.[[http://www.pbs.org/wgbh/pages/frontline/shows/sats/interviews/jencks.html PBS Jencks Interview] "If we change the names of the tests, they still measure the same thing but it wouldn't convey this idea that somehow you've gotten the potential of somebody when you measured their IQ. And I think that creates a big bias, because the people who do badly on the tests are labeled as people with low potential in many people's minds and they sometimes even believe that about themselves."]
They assert that non-cultural environmental factors cause gaps measured by the tests, rather than any possible innate difference based on genetics, and to use these tests as a measure of innate difference is misleading and improper.[{{AYref|Jencks and Phillips|1998}} "... we find it hard to see how anyone reading these studies with an open mind could conclude that innate ability played a large role in the black-white gap."]
Regarding the IQ gaps in the U.S., it has 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 is suggested that 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.] One author has attempted to itemize the many factors that constitute the differences in social and socioeconomic environments between blacks and whites.[http://personnelselection.com/adverse.impact.htm ]
[[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 intelligence between ethnic groups have occurred throughout history. [[Aristotle]] in the 4th century B.C. and [[Cicero]] in the 1st. century B.C. disparaged the intelligence of the northern Europeans of the time, as did the [[Moors]] in [[Iberian Peninsula|Iberia]] in the 11th century.
[Aristotle: "Having spoken of the number of the citizens, we will proceed to speak of what should be their character. This is a subject which can be easily understood by any one who casts his eye on the more celebrated states of [[Greece|Hellas]], and generally on the distribution of races in the habitable world. Those who live in a cold climate and in Europe are full of spirit, but wanting in intelligence and skill; and therefore they retain comparative freedom, but have no political organization, and are incapable of ruling over others. Whereas the natives of Asia are intelligent and inventive, but they are wanting in spirit, and therefore they are always in a state of subjection and slavery. But the Hellenic race, which is situated between them, is likewise intermediate in character, being high-spirited and also intelligent. Hence it continues free, and is the best-governed of any nation, and, if it could be formed into one state, would be able to rule the world." (Aristotle, ''[[Politics (Aristotle)|Politics]]'', [http://www.constitution.org/ari/polit_07.htm ch. 7]).
]
[[Cicero]]: "Do not obtain your slaves from Britain because they are so stupid and so utterly incapable of being taught that they are not fit to form a part of the household of Athens." Attributed to Cicero's ''Epistulae ad Atticum'' (Letters to Atticus), 68 BC-43 BC ([http://ebooks.cib.unibo.it/archive/00000151/ latin text]). Translation: {{AYref|Cicero|1918}}.
"Races north of the [[Pyrenees]] are of cold temperament and never reach maturity; they are of great stature and of a white colour. But they lack all sharpness of wit and penetration of intellect." Attributed to "Said of Toledo (a [[Moors|Moorish]] savant)" by {{AYref|Benedict|1999}} (p.34), originally quoted in {{AYref|Hogben|1931}}.
Although IQ is regarded as being highly heritable, this does not mean that IQ differences between racial groups are necessarily genetic in origin, because estimates of heritability are dependent on a given environment. For example, in [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15133590&query_hl=23&itool=pubmed_DocSum schizophrenia], also regarded as being highly heritable, increased rates in second and third generation immigrants to Western European countries do not seem to be the result of increased genetic susceptibility, but another, as yet unidentified, environmental factor.
A number of environmental factors are agreed to be likely 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 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.[See [[Race and intelligence (Explanations)#Nongenetic biological factors]]]
The secular, international increase in test scores, commonly called the [[Flynn effect]], is seen by Flynn and others as reason to expect the eventual convergence of average black and white IQ scores. However, research has shown that the gap in black and white test scores in America remained stable throughout the 20th century, fluctuating by less than one point[[http://newswire.ascribe.org/cgi-bin/behold.pl?ascribeid=20061109.113857&time=13%2046%20PST&year=2006&public=0 New Evidence Race-IQ Gap Remains; Findings Could Undermine Affirmative Action Policies]]. As demonstrated by Flynn, the average IQ scores in several countries have increased about 3 points per decade during the 20th century, which he and others attribute predominantly to environmental causes.[{{AYref|Flynn|1987}}, {{AYref|Flynn|1987b}}, {{AYref|Flynn|1999}}, {{AYref|Flynn|1999b}}] This means, given the same test, the mean black American performance today could be higher than the mean white American performance in 1920, though the gains causing this appear to have occurred predominantly in the lower half of the IQ distribution.[{{AYref|Colom et al.|2005}}] If changes in environment can cause changes in IQ over time, they argue, then contemporary differences between groups could also be due to an unknown environmental factor. 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 anticipate that the IQ gap among races might change in the future or is even now changing. An added complication to this hypothesis is the question of whether the secular IQ gains can be predominantly a real change in cognitive ability. Flynn's face-value answer to this question is "No",[{{AYref|Flynn|1999}}] and other researchers have found reason to concur.[{{AYref|Wicherts et al.|2004}} 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, some of the inter-generational difference in IQ is attributable to bias or other artifacts, and not real gains in general intelligence or higher-order ability factors, unlike the B-W IQ gap. An analysis by {{AYref|Rushton|1999}} found that the IQ increases associated with the Flynn effect did not produce changes in ''g'', which Rushton compares to the finding by {{AYref|Jensen|1998a}} that IQ increases associated with adoption likewise do not increase ''g''. {{AYref|Flynn|1999b}} disagrees with Rushton's analysis.] Responding to such concerns, {{AYref|Dickens and Flynn|2001}} have proposed a solution which rests on genotype-environment correlation, hypothesizing that small initial differences in environment cause feedback effects which magnify into large IQ differences.[{{AYref|Rowe and Rodgers|2002}} and others find this hypothesis unsupported by the available evidence. {{AYref|Dickens and Flynn|2002}} respond to these criticisms.] Such differences would need to develop before age 3, when the black-white IQ gap can be first detected.[{{AYref|Rushton and Jensen|2005a}}]
Many studies that attempt to test for heritability find results that do not support the partly-genetic hypothesis (20-80% genetic). They include studies on IQ and skin color,[{{AYref|Shuey|1966}} reported the average correlation between skin color and IQ among American blacks is .1; for comparison {{AYref|Parra|2004}} found the correlation between skin color and fraction of West-African ancestry is .4.] self-reported European ancestry,[{{AYref|Jenkins|1936}}] children in post WWII Germany born to black and white American soldiers,[{{AYref|Eyferth|1961}}; see note below] blood groups,[{{AYref|Scarr et al.|1977}}, {{AYref|Loehlin et al.|1973}}] and mixed-race children born to either a black or a white mother.[{{AYref|Willerman et al.|1974}}] Many intervention and adoption studies also find results that do not support the genetic hypothesis.[{{AYref|Nisbett|2005}}] 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 due to their age, lack of replication, problems with their sample population, or that they do in fact support the partly-genetic hypothesis.[{{AYref|Rushton and Jensen|2005b}} argue that these studies are "peculiarly old, the mean year of publication being 1960" and "actually very weak and nondecisive, not having been replicated even once". {{AYref|Jensen|1998b}}, for example, points out that while the study of children born in post-WWII Germany finds no difference between white and interracial children, it does find a large difference in IQ between boys and girls, suggesting that sampling artifacts have affected the results.]
{{AYref|Fryer and Levitt|2006}}, with data from "the first large, nationally representative sample" of its kind, report finding only a very small racial difference when measuring mental function for children aged eight to twelve months, and that even these differences disappear when including a "limited set of controls".[{{AYref|Fryer and Levitt|2006}} [http://post.economics.harvard.edu/faculty/fryer/papers/fryer_levitt_ecls_babies.pdf Testing for Racial Differences in the Mental Ability of Young Children] "On tests of intelligence, Blacks systematically score worse than Whites, whereas Asians frequently outperform Whites. Some have argued that genetic differences across races account for the gap. Using a newly available nationally representative data set that includes a test of mental function for children aged eight to twelve months, we find only minor racial differences in test outcomes (0.06 standard deviation units in the raw data) between Blacks and Whites that disappear with the inclusion of a limited set of controls. The only statistically significant racial difference is that Asian children score slightly
worse than those of other races. To the extent that there are any genetically-driven racial differences in intelligence, these gaps must either emerge after the age of one, or operate along dimensions not captured by this early test of mental cognition."] They argue that their report poses "a substantial challenge to the simplest, most direct, and most often articulated genetic stories regarding racial differences in mental function."[''How similar are fluid cognition and general intelligence? A developmental neuroscience perspective on fluid cognition as an aspect of human cognitive ability'', Behavioral and Brain Sciences (2006), 29: 109-125 Cambridge University Press, Clancy Blair. Multiple comments can be seen on [http://scholar.google.se/scholar?as_q=&num=10&btnG=S%C3%B6k+Scholar&as_epq=How+similar+are+fluid+cognition+and+general+intelligence&as_oq=&as_eq=&as_occt=any&as_sauthors=&as_publication=Behavioral+and+Brain+Sciences&as_ylo=&as_yhi=&as_allsubj=all&hl=sv&lr= Google Scholar.]]
=== Genetic explanations ===
:''See also: [[Inheritance of intelligence]]''
[[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 US IQ gap is partially 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 hereditarian hypothesis (50% genetic-50% environmental) can formulate new predictions, some of which can be tested, whereas a completely culture-only hypothesis (0% genetic-100% environmental) can't, as it merely accommodates anomalies.[{{AYref|Rushton and Jensen|2005a}}]
To support these claims, they often cite several lines of evidence that they interpret as support for a partly genetic cause of group differences in IQ:
# Black–White–East Asian differences in IQ, reaction time, and brain size are observed worldwide in a range of cultures and environments. In the United States, significant Black-White IQ differences are observable at every age above 3 years, within every occupation or socioeconomic level tested, in every region of the country, and at every time since the invention of ability tests.[{{AYref|Jensen|1998b}}]
# Jensen and other have argued that the magnitude of race differences in certain studies on different IQ subtests correlates with the extent to which those subtests measures ''g'',[For example, see {{AYref|Rushton and Jensen|2003}}; see also [[Spearman's hypothesis]]] which also correlates with measures of the subtests heritability.[for example, [[inbreeding depression]] scores measured in Japan predict the magnitude of the Black-White gap in the United States. ({{AYref|Rushton|1989a}})] They conclude that race differences have a partly biological basis.[reviewed by {{AYref|Jensen|1998b}}]
# The rising [[IQ#Development|heritability of IQ]] with age (within all races; studies have found on average in the developed world heritability starts at 20% in infants, rises to 40% in middle childhood, and peaks at 80% in adulthood); and studies showing the virtual disappearance (~0.0) by adulthood of shared environmental effects on IQ (for example, family income, education, and home environment), with adopted siblings partaking in the studies no more similar in IQ than with strangers[{{AYref|Plomin et al.|2001}}]
# Studies of US comparisons of both parents to children and siblings to each other finding [[Regression toward the mean|regression]] to differing means for different races (85 for Blacks and 100 for Whites) across the entire range of IQs,[for example, the children of wealthy, high IQ Black parents score lower than the children of poor, low IQ White parents ({{AYref|Jensen|1998b}}, p. 358); and for Black and White children with an IQ of 120, the siblings of the Black children average an IQ of 100 whereas the siblings of the White children average an IQ of 110; in comparison, for Black and White children with an IQ of 70, the siblings of the Black children average an IQ of 78 whereas the siblings of the White children average an IQ of 85 ({{AYref|Jensen|1973}}, pp. 107–119))] despite the fact that siblings are matched for shared environment and genetic heritage, with regression unaffected by family socioeconomic status and generation examined[http://www.lrainc.com/swtaboo/taboos/cmurraybga0799.pdf]
{{A(Y)ref|Rushton and Jensen|2005a}} believe that the best explanation is that 50%-80% of the group differences in average US IQ 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}}] For fuller listings of evidence for and against the partly-genetic (20-80% genetic) position, see [[Race and intelligence (Explanations)#Comparison of explanations|Comparison of explanations]].
Other evidence, such as [[Minnesota Transracial Adoption Study|transracial adoption]], certain racial admixture studies, behavior genetic modeling of group differences, "life-history" traits, and evolutionary explanations have also been proposed to indicate a genetic contribution to the IQ gaps and explain how these arose. Critics of this view, such as [[Robert Sternberg]], argue that these studies are either flawed and thus inconclusive, or else that they support a primarily environment (<20% genetic) hypothesis.[For example: {{AYref|Nisbett|2005}}, {{AYref|Suzuki and Aronson|2005}}, {{AYref|Sternberg|2005}}, {{AYref|Dickens|2005}}] For example, {{AYref|Dolan and Hamaker|2001}} argue that the statistical methods linking the Black-White gap to ''g'' are insufficient.[{{AYref|Dolan and Hamaker|2001}} reanalyzed the data from several earlier studies and concluded that Spearman's hypothesis is not an "empirically established fact" (i.e., that Black-White IQ differences may be due to differences in common factors other than ''g'') due to insufficient power in the data to choose between alternative models. "This leaves the validity of Spearman's hypothesis, considered a central justification for the genetic explanation, an unresolved question." However, they did confirm that the Black-White IQ gap is not due to measurement artifacts, and is instead due to some measured factor that varies both within and between groups.]
Several recent studies have found some neuronal genes have variants that have spread to high frequencies under selective pressure and now occur in different frequencies in different global populations.[For example, a new variant of the [[ASPM]] gene is estimated to have swept to high frequency 500-14,100 years ago, with researchers favouring 5,800 as most likely.] The cause of the selective sweep and the effects of these variants are generally not yet known, although some suspect that they could be related to intelligence.[{{AYref|Dorus et al.|2004}}, {{AYref|Tang|2006}}. {{AYref|Woods et al.|2006}} found no effect from [[ASPM]] and [[microcephalin]] on brain size, which they conclude "suggests that the selective pressure on these genes may be related to subtle neurobiological effects or to their expression outside the brain."] Although neurogenic diversity theoretically increases the chances of functional diversity, ultimately, very little is known about the actual impact of these variants, and the researchers caution that they may not have anything to do with cognition or intelligence at all.["Our studies indicate that the trend that is the defining characteristic of human evolution - the growth of brain size and complexity - is likely still ongoing. . . [But as well] just because these genes are still evolving doesn't necessarily mean they make you any smarter. . . We’ve evolved genes for selfishness, violence, cruelty—all of which are in place because they may make survival easier." [http://chronicle.uchicago.edu/050922/brainevolution.shtml University of Chicago Chronicle, September 22, 2005, Vol. 25 No. 1] "Lahn’s analysis of genes indicates human brain continues to evolve."]
=== Expert opinion ===
A survey was conducted in 1987 of a broad sample of 1,020 scholars in specialties that would give them reason to be knowledgeable about IQ (but not necessarily about race). The survey was given to members of the [[American Education Research Association]], [[National Council on Measurement in Education]], [[American Psychological Association]], [[American Sociological Association]], [[Behavior Genetics Association]], and [[Cognitive Science Society]]. According to the report, regarding the question "The source of black-white difference in IQ":
This is perhaps the central question in the IQ controversy. Respondents were asked to express their opinion of the role of genetic differences in the black-white IQ differential. Forty-five percent believe the difference to be a product of both genetic and environmental variation, compared to only 15% who feel the difference is entirely due to environmental variation. Twenty-four percent of experts do not believe there are sufficient data to support any reasonable opinion, and 14% did not respond to the question. Eight experts (1%) indicate a belief in an entirely genetic determination.[{{AYref|Snyderman and Rothman|1987}}.]
[[Robert Sternberg]] cautioned against supposing that the survey represented anything but opinion saying, "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. Carol Swain, author of ''The New White Nationalism'' reacted with some dismay to the survey, stating:
At least one important survey suggests that a belief in the biological inferiority of some races in regard to intelligence is more common than generally supposed. Smith College professor Stanley Rothman and Harvard researcher Mark Snyderman surveyed a sample of mostly scientific experts in the field of educational psychology in the late 1980s and found that 53 percent believed IQ differences between whites and African Americans were at least partly genetic in origin, while only 17 percent attributed the IQ differences to environmental factors alone (the remainder either believed the data was currently insufficient to decide the issue or refused to answer the question).
According to the [[American Psychological Association]]'s [[Race and intelligence#Collective Statements|1995 task force report]] on intelligence research:
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 subsequently published eleven critical responses in 1997, most arguing that the report failed to examine adequately the evidence for partly-genetic (20-80% genetic) explanations.[(''[[American Psychologist]]'', January 1997)] [[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 arguments omitted from the task force report.[http://www.commentarymagazine.com/production/files/murray0905.html#_ednref50]]
The report did agree with many of the non-race-based statements on intelligence made in ''The Bell Curve''[The authors of the report agreed that IQ scores have high predictive validity for individual differences in school achievement. They confirmed the predictive validity of IQ for adult occupational status, even when variables such as education and family background have been statistically controlled. They agree that individual differences in intelligence are substantially influenced by genetics (75% in adults). Consistent with Herrnstein and Murray's findings, they state there is little evidence to show that childhood diet influences intelligence except in cases of severe malnutrition.] and concludes with a call for more reflection in debates on intelligence and for a "shared and sustained effort" in more research to answer the many unanswered questions that remain.["In a field where so many issues are unresolved and so many questions unanswered, the confident tone that has characterized most of the debate on these topics is clearly out of place. The study of intelligence does not need politicized assertions and recriminations; it needs self-restraint, reflection, and a great deal more research. The questions that remain are socially as well as scientifically important. There is no reason to think them unanswerable, but finding the answers will require a shared and sustained effort as well as the commitment of substantial scientific resources. Just such a commitment is what we strongly recommend."]
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|Rowe|2005}}, {{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 validity|Practical importance of IQ]]''
===Within societies===
====Scope====
The distribution of IQ scores among individuals of each race overlap substantially. In a random sample of equal numbers of US Blacks and Whites, {{A(Y)ref|Jensen|1998b}} estimates most variance in IQ would be unrelated to race or social class.[p. 357. Equal-sized random samples of children from California schools were used for this analysis. Social class was rated on a ten-point scale based on parents' education and occupation. Only 30% of total variance in IQ is associated with differences between race and social class, whereas 65% exists within each racial and social class group. The single largest source of IQ variance exists between siblings within the same family.] The average IQ difference between two randomly paired people from the U.S. population is approximately 17 points, and this only increases to 20 points when the pair are black and white. When the pair are siblings, the average difference is still 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 (20-80% 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, it could be argued that an indirect outcome of social egalitarianism would be to raise the genetic contribution to intelligence to as high as possible, by minimizing environmental inequalities and any negatively IQ-impacting cultural and socio-economic differences.[''[[The Blank Slate]]'', pp. 106-107.] If all such inequalities could somehow be completely eliminated, any remaining group (but not individual) IQ differences would then be 100% hereditary: the only remaining factor that could potentially contribute to race-based outcome differences.
====Practical importance====
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.[{{AYref|Sackett et al.|2004}}: "Sub-group differences in performance on high-stakes tests represent one of American society's most pressing social problems, and mechanisms for reducing or eliminating differences are of enormous interest" (p.11).] {{AYref|Gordon|1997}} and {{AYref|Gottfredson|1997b}} argue that the IQ gap is reflected by gaps in the academic, economic, and social factors correlated with IQ. However, some{{weasel-inline}} 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 validity|Practical importance of IQ]]".)
The effects of differences in mean IQ between groups (regardless if the cause is social or biological) are amplified by two statistical characteristics of IQ. 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%;"
|+ '''IQ Cohorts & Significance (U.S.)'''
|- bgcolor=#ccccff
!IQ range
!Whites
!Blacks
!Black:White ratio
!Training prospects
!High school dropout
!Lives in poverty
!"Middle-Class Values" index[The 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). Training prospects from {{AYref|Wonderlic|1992}} and {{AYref|Gottfredson|1997}}. Significance data is from {{AYref|Herrnstein and Murray|1994}}, and is based on Whites only. Results from the total population are nearly indistinguishable. Results for Blacks only are similar but not identical (see the table below for comparisons between groups). Note that these are merely [[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, could theoretically have large effects for the United States population as a whole. As a demonstration of these possible effects, {{A(Y)ref|Herrnstein and Murray|1994}} used a [[Resampling (statistics)|resampling technique]] to argue that, all else equal, a simulated 3-point drop in average IQ had little effect on factors like marriage, divorce, or unemployment. However, their study found that a simulated drop in IQ from 100 to 97-points increased poverty rates by 11% and the proportion of children living in poverty by 13%. In the simulation, similar rises occurred 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, when they simulated an increase in average IQ of 3-points to 103, they calculated that poverty rates fell 25%, children living in poverty fell 20%, and high school drop-out rates fell 28%.[For this calculation, [[Richard Herrnstein|Herrnstein]] and [[Charles Murray|Murray]] altered 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 reached 103. Their random deletion procedure was conducted twice and the calculated results were averaged together. Herrnstein and Murray note that their calculation ignore secondary effect. ({{AYref|Herrnstein_and_Murray|1994}}, pp. 364-368)]
Professors [[James Heckman]] and [[Nicholas Lemann]], as well as several other scholars and scientists have the criticized validity and reliability of the data which led to the aforementioned findings by {{A(Y)ref|Herrnstein and Murray|1994}}.[[http://www.reason.com/news/show/29636.html Cracked Bell] by Professor [[James Heckman]] in ''[[Reason]]'' (March 1995).][[http://www.slate.com/id/2416 The Bell Curve Flattened] by [[Nicholas Lemann]] in ''[[Slate]]'' (January 1996).]
====Controlling for IQ====
{| border="2" cellpadding="4" cellspacing="0" style="margin: 1em 0 1em 1em; background: #ccccff; border: 1px #aaa solid; border-collapse: collapse; font-size: 95%;" ALIGN="center"
|+ '''Group Outcomes After Being Statistically Adjusted to Match IQ'''
|- bgcolor=#ccccff
!Condition (matching IQ)
!Black %
!Latino %
!White %
|- bgcolor=E9E8FF
| High school graduation (103) || 93 || 91 || 89
|- bgcolor=#DFE0FF
| College graduation (114) || 68 || 49 || 50
|- bgcolor=E9E8FF
| High-level occupation (117) || 26|| 16 || 10
|- bgcolor=#DFE0FF
| Living in poverty (100) || 11 || 9 || 6
|- bgcolor=E9E8FF
| Unemployed for 1 month or more (100) || 15 || 11 || 11
|- bgcolor=#DFE0FF
| Married by age 30 (100) || 58 || 75 || 79
|- bgcolor=E9E8FF
| Unwed mother with children (100) || 51 || 17 || 10
|- bgcolor=#DFE0FF
| Has ever been on welfare (100) || 30 || 15 || 12
|- bgcolor=E9E8FF
| Mothers in poverty receiving welfare (100) || 74 || 54 || 56
|- bgcolor=#DFE0FF
| Having a low birth-weight baby (100) || 6 || 5 || 3
|- bgcolor=E9E8FF
| Average annual wage (100) || $25,001 || $25,159 || $25,546
|- bgcolor=#DFE0FF
| Men ever incarcerated (100) || 5 || 3 || 2
|- bgcolor=E9E8FF
| "Middle-Class Values" index[[http://www.reason.com/news/show/29636.html Cracked Bell] by Professor [[James Heckman]] in ''[[Reason]]'' (March 1995).][[http://www.slate.com/id/2416 The Bell Curve Flattened] by [[Nicholas Lemann]] in ''[[Slate]]'' (January 1996).]
|}
Because IQ correlates with a number of social and economic outcomes that have been found to differ between the black and white populations overall, ''[[The Bell Curve]]'' argues that the disparities in outcomes are due to group differences in IQ (See above chart).Professors [[James Heckman]] and [[Nicholas Lemann]] and others claim that its findings are based on data that is not completely valid and reliable.[[http://www.reason.com/news/show/29636.html Cracked Bell] by Professor [[James Heckman]] in ''[[Reason]]'' (March 1995).][[http://www.slate.com/id/2416 The Bell Curve Flattened] by [[Nicholas Lemann]] in ''[[Slate]]'' (January 1996).]
According to Murray and Herrnsteins' ''Bell Curve'', when IQ is statistically controlled for, 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.] Conversely, controlling for IQ in the above studies also reduces the apparent effect of wealth, race and schooling due to this same correlation.
White populations are not homogeneous groups regarding real-world outcomes. For example, in the U.S. 33.6% of persons with self-reported Scottish ancestry 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===
[[Image:Discover_Sept_1982.jpg|right|frame|[[Richard Lynn]]'s early research on Japanese IQ initiated an academic controversy and became part of Western countries' surprise in the early 1980s at the Japanese' unexpected economic and industrial achievements. ([[Discover (magazine)|''Discover'']]
1982)[http://www.discover.com/issues/jul-05/rd/lookback-in-discover/] ]]
Some people have attributed differential economic growth between nations to differences in the intelligence of their populations. One example is Richard Lynn's ''[[IQ and the Wealth of Nations]]''. The book 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]."<;/ref> 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 IQ[This theory is discussed by {{AYref|Jensen|1998b}} (pp. 435-437), {{AYref|Lynn|1991b}} and {{AYref|Rushton|2000}} in general and by both {{AYref|Wade|2006}} and [http://www.isteve.com/diamond.htm Steve Sailer] with respect to ''Guns, Germs, and Steel''. See [[Race and intelligence (Explanations)#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===
The book ''[[World on Fire]]'' notes the existence in many nations of minorities that have created and control a disproportionate share of the economy, a [[market-dominant minority]]. Examples include Chinese in Southeast Asia; [[India]]ns in the United States and Britain; 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, [[Indian American|Asian Indians]], Japanese, and Chinese earn incomes 1.72, 1.42, 1.32, and 1.12 times the American average, respectively.[{{AYref|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 University|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.[{{AYref|Weyl|1969}} and {{AYref|Weyl|1989}}, cited by {{AYref|Lynn|1991a}}.] 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. Over half of the world chess champions from 1886 to 2000 had at least one Ashkenazi Jewish parent.[[http://www.jinfo.org/Chess_Champions.html Jewish World Chess Champions] accessed December 30th, 2005.]
Some studies have shown significant variation in IQ subtest profiles between groups. In one analysis of IQ studies on [[Ashkenazi Jews]], for example, high verbal and mathematical scores, but average or below average visuospatial scores were found.[{{AYref|Cochran et al.|2005}}, p. 4] In a separate study, East Asians demonstrated high visuospatial scores, but slightly above average, 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)] The professions in which these populations tend to be over-represented differ, and some believe the difference is directly related to IQ subtest score patterns asserted to exist.[{{AYref|Lynn|1991a}}] The high visiuospatial/average to below average verbal pattern of subtest scores has also been asserted to exist in fully assimilated third-generation Asian Americans, as well as in the [[Inuit]] and [[Indigenous peoples of the Americas|Native Americans]] (both of [[Human migration#Earliest migrations|Asian origin]]).[{{AYref|Murray and Herrnstein|1994}}]
== Public debate and policy implications ==
{{main|Race and intelligence (Public controversy)}}
===Media portrayal===
{{Main|Race and intelligence (Media portrayal)}}
Some researchers argue media coverage of intelligence-related research is often inaccurate and misleading. Snyderman and Rothman conducted a study of this phenomenon in 1988, drawing from their 1987 survey of expert opinion of intelligence-related topics. Media attention given to William Shockley in the mid 1980's often cited his Nobel Laureate status, but frequently omitted that the prize was given for electronics, not psychology.
===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]
Another cricism is that it "causes major psychological harm to millions of black children and adults (with respect to self-esteem, career expectations, interracial relationships, etc.)".[{{AYref|Lieberman|2001}} [http://www.ssc.uwo.ca/psychology/faculty/rushtonpdfs/Lieberman2001CA.pdf]] For example, in response to ''The Bell Curve'' [[Ashley Montagu]], who famously stated the ideology of race is "man's most dangerous myth," wrote:
It is generally held that anyone who cries "Fire" in a crowded theatre should be held responsible for the consequences of his conduct. The same rule should apply to anyone who, motivated by racism, publishes inflammatory falsehoods concerning others, whether they be individuals, groups, or populations; they should by law be held responsible for their conduct. More than 200 years of racism, libel and slander, are enough, and so it is with use of IQ tests, which in a very real sense represent demeaning falsehoods, whether they maliciously intended or not.[{{AYref|Montagu|1999}} p. 199]
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 to be one of the greatest evolutionary theorists of the 20th century,[{{AYref|Dawkins|2000}} [http://www.edge.org/3rd_culture/hamilton/hamilton_index.html *]]
argue that suppressing race and intelligence research is actually more harmful than dealing with it honestly. [[Linda Gottfredson]], a prominent professor whose work has been influential in U.S. workplace policy and who's also a [[Pioneer fund]] grantee 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|2006b}}, p. 2 end]
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.[ {{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)}}
====Against those who question the utility of "race"====
It is asserted that misguided political correctness has led to large-scale denial of recent developments in the human sciences, including research regard group differences in cognitive ability.[See for example Morton Hunt's ''The New Know-Nothings: The Political Foes of the Scientific Study of Human Nature'' (1999; pp. 63-104) which argues that recent years "have witnessed a dramatic upsurge in efforts to impose limits on the freedom of social scientists to explore controversial research questions, particularly questions that could yield answers distasteful to those with certain sociopolitical or ideological agendas" ({{AYref|Lilienfeld|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. Pinker states regarding recent discussions regarding group differences:
''"Whether or not these hypotheses hold up ... proponents of ethnic and racial differences in the past have been targets of censorship, violence, and comparisons to Nazis. Large swaths of the intellectual landscape have been reengineered to try to rule these hypotheses out a priori (race does not exist, intelligence does not exist, the mind is a blank slate inscribed by parents). The underlying fear, that reports of group differences will fuel bigotry, is not, of course, groundless." [{{AYref|Pinker|2006}} See {{AYref|Tucker|2002}} for another account.]
====Against those who support the utility of "race"====
Accusations have also been aimed at the [[Pioneer Fund]], which according to the [[Southern Poverty Law Center]] "has funded most American and British race scientists, including a large number cited in The Bell Curve"[[http://www.splcenter.org/intel/intelreport/article.jsp?pid=106#14]). [[Pioneer Fund]] grantees include the current head [[J. Phillipe Rushton]], [[Arthur Jensen]], [[Linda Gottfredson]], [[Richard Lynn]], [[Hans Eysenck]], [[Thomas Bouchard]], [[David T. Lykken|David Lykken]], [[Henry Garrett]], [[William Shockley]], [[Philip A. Vernon|Philip Vernon]], and [[Audrey M. Shuey|Audrey Shuey]].] The leading critics of the fund include the [[SPLC]], IQ critic [[William H. Tucker]], and historian [[Barry Mehler]] and his [[Institute for the Study of Academic Racism]].Pioneer fund has been characterized by the [[Southern Poverty Law Center]] as having a [[eugenics|eugenic]] and [[racism|racist]] political agendaa and being a "[[hate group]]," using the definition "attack[ing] or malign[ing] an entire class of people, typically for their immutable characteristics". According to [[Keith Booker]], president of the Wilmington (Del) chapter of the [[NAACP]], the Pioneer Fund "supports only research that tends to come out with results that further the division between races... by justifying the superiority of one race and the inferiority of another... this research is being done in the name of white supremacy" ([http://www.mugu.com/cgi-bin/Upstream/kaufman-delaware RON KAUFMAN The Scientist, Vol:6, #14, July 6, 1992]). Some critics have argued that some of the prominent researchers advancing genetic explanations have also opposed affirmative action and school integration.({{AYref|Tucker|2002}}) Pioneer fund has been criticized as having a [[eugenics|eugenic]] and [[racism|racist]] political agenda ([http://www.fair.org/index.php?page=1271 Racism Resurgent:How Media Let The Bell Curve's Pseudo-Science Define the Agenda on Race]), and a claimed racist and Nazi-sympathizer history.(http://www.tolerance.org/maps/hate/index.html). Prominent critic [[Ulric Neisser]], who was the chairman of the APA's [[Race and intelligence#Expert opinion|1995 task force]] on intelligence research regards the fund as helping "change the face of social science" and as being "a weak plus".[Neisser states in his book review ({{AYref|Neisser|2004}}) that, though race and intelligence research "turns [his] stomach . . . the research funded by Pioneer has helped change the face of social science." Neisser also writes "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."]
Researchers who accept grants from the Pioneer Fund have been subject to criticism regarding bias. Anti-racist ''[[Searchlight Magazine]]'' notes Pioneer head [[J. Phillipe Rushton]] has given a speech at an [[American Renaissance]] meeting that Searchlight describes as a "veritable 'who’s who' of American [[white supremacy]]." [http://www.searchlightmagazine.com/index.php?link=template&story=162]. In the early 1990s, the University of Delaware imposed a "prohibition on the receipt of funding (by a faculty member) from the Pioneer Fund, amidst accusations that the Fund had a "history of supporting racism, anti-semitism and other discriminatory practices".[http://www.aaup.org/Legal/info%20outlines/research.htm]
Grantee [[Linda Gottfredson]] fought a two-year battle with the university before it rescinded its prohibition, arguing that a ban on funding restricted academic freedom.[http://www.the-scientist.com/article/display/11418/] Although there is no direct evidence that the Pioneer Fund has biased the research one critic notes:
''"The real question is not did the Pioneer Fund make you alter your scientific findings but why did the Pioneer Fund fund you?""It's not so much a question of whether or not they influence an individual scientist but rather the scientists they choose to fund in the first place, Weizmann added."''[[http://www.ferris.edu/isar/Institut/pioneer/rushton.htm]]
[[Robert A. Gordon]], criticized for accepting grants from the [[Pioneer Fund]], replied to media criticisms of grant-recipients: "Politically correct disinformation about science appears to spread like wildfire among literary intellectuals and other nonspecialists, who have few disciplinary constraints on what they say about science and about particular scientists and on what they allow themselves to believe."[([http://www.pioneerfund.org/Gordon.pdf Gordon 1997], p.35)]
====Threats and harassment====
{{AYref|Gottfredson|2005a}} has summarized the history of harassment and violence against [[Arthur Jensen]] and others.["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."]
===Policy implications===
:''See also: [[Intelligence and public policy]]''
Public policy implications of IQ and race research are one of the greatest sources of controversy surrounding this issue.
Some proponents of a partly genetic (20-80% genetic) interpretation of the IQ gap, such as {{A(Y)ref|Rushton and Jensen|2005a}} and {{A(Y)ref|Gottfredson|2005b}}, have sometimes argued that their interpretation does not in itself demand any particular policy response: while a conservative/[[Libertarianism|libertarian]] commentator[ For example, the policy recommendations of ''[[The Bell Curve]]'' were denounced by many.{{fact}} {{AYref|Herrnstein and Murray|1994}} wrote: "We can imagine no recommendation for using the government to manipulate fertility that does not have dangers. But this highlights the problem: The United States already has policies that inadvertently social-engineer who has babies, and it is encouraging the wrong women. ''If the United States did as much to encourage high-IQ women to have babies as it now does to encourage low-IQ women, it would rightly be described as engaging in aggressive manipulation of fertility.'' The technically precise description of America's fertility policy is that it subsidizes births among poor women, who are also disproportionately at the low end of the intelligence distribution. We urge generally that these policies, represented by the extensive network of cash and services for low-income women who have babies, be ended. (p. 548)"
Two year later the [[Personal Responsibility and Work Opportunity Act|1996 U.S. welfare reform]] substantially cut these programs. In a discussion of the future political outcomes of an intellectually stratified society, they stated that they: "fear that a new kind of conservatism is becoming the dominant ideology of the affluent - not in the social tradition of an [[Edmund Burke]] or in the economic tradition of an [[Adam Smith]] but ’conservatism’ along Latin American lines, where to be conservative has often meant doing whatever is necessary to preserve the mansions on the hills from the menace of the slums below. (p. 518)"Moreover, they fear that an increasing welfare will create a "custodial state": "a high-tech and more lavish version of the [[Indian reservation]] of some substantial minority of the nation’s population. They also predict increasing totalitarianism: It is difficult to imagine the United States preserving its heritage of individualism, equal rights before the law, free people running their own lives, once it is accepted that a significant part of the population must be made permanent wards of the states. (p. 526)"] may feel the results justify, for example, 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}}] Since all races have representatives at all levels of the IQ curve, this means any policy based on low IQ affects members of all races.
According to the "[[Mainstream Science on Intelligence]]" statement published in ''[[Intelligence (journal)|Intelligence]]'' in 1997:
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 health care, nutrition, regulation of environmental toxins, and geographic distribution of diseases and control strategies between the developing world and developed nations have all been subjects of policies or policy recommendations (see [[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=
== See also ==
* [[Ashkenazi intelligence]]
* [[Brain to body mass ratio]]
* [[Craniometry]]
* [[Hominid intelligence]]
* [[Neuroscience and intelligence]]
* [[Height and intelligence]]
* [[Race and crime]]
* [[Sex and intelligence]]
* [[Scientific racism]]
* ''[[The Mismeasure of Man]]''
==Notes==
== 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.aei.org/events/eventID.1425,filter.all,type.upcoming/event_detail.asp James Flynn and Charles Murray debate] - [http://www.reason.com/news/show/116991.html news summary]
* [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://web.archive.org/web/20060515163834/http://www.commentarymagazine.com/production/files/murray0905.html archived version]
* [http://brookings.nap.edu/books/0815746091/html/index.html The Black-White Test Score Gap (1998)] online (page-image) version of ISBN 0-8157-4609-1
===Others===
* [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.townhall.com/columnists/ThomasSowell/2002/10/01/race_and_iq Part 1], [http://www.townhall.com/columnists/ThomasSowell/2002/10/02/race_and_iq:_part_ii Part 2], [http://www.townhall.com/columnists/ThomasSowell/2002/10/03/race_and_iq:_part_iii Part 3] by [[Thomas Sowell]]
* [http://skepdic.com/iqrace.html The ''Skeptic's Dictionary'' entry on IQ and race]
* [http://www.skeptic.com/eskeptic/05-02-18.html#raceskeptic (Skeptic Magazine): Two book reviews, by Paul R. Gross and Alondra Oubre, of Sarich’s and Miele’s book, Race: The Reality of Human Differences]
* [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://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://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.tnr.com/doc.mhtml?i=20060626&s=pinker062606&c=1 The Lessons of the Ashkenazim: Groups and Genes], [[Steven Pinker]], June 2006, ''[[The New Republic]]''.
* [http://jonjayray.tripod.com/knowledg.html Are all races equally intelligent? -- Or: When is knowledge knowledge?] by John J. Ray
* [http://iqte.st/blog/?p=258 Black-White Gap in IQ Scores Closing, Study Finds]
{{Race and intelligence}}
{{Race and sex differences}}
[[Category:Psychometrics]]
[[Category:Race and intelligence controversy| ]]
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