Intelligence: Knowns and Unknowns
Encyclopedia
Intelligence: Knowns and Unknowns was a 1995 report issued by a Task Force created by the Board of Scientific Affairs of the American Psychological Association
.
had concluded that after the publication of The Bell Curve
(1994) and the following debate that there were "serious misunderstandings" and "that there was urgent need for an authoritative report on these issues—one that all sides could use as a basis for discussion". Furthermore, "Another unfortunate aspect of the debate was that many participants made little effort to distinguish scientific issues from political ones, Research findings were often assessed not so much on their merits or their scientific standing as on their supposed political implications." The report stated that "The charge to our Task Force was to prepare a dispassionate survey of the state of the art: to make clear what has been scientifically established, what is presently in dispute, and what is still unknown. In fulfilling that charge, the only recommendations we shall make are for further research and calmer debate."
It was originally published on August 7, 1995. It was authored by a task force of 11 experts. The APA Board on the Advancement of Psychology in the Public Interest (BAPPI) nominated one member of the Task Force. The Committee on Psychological Tests and Assessment nominated another. A third was nominated by the Council of Representatives. The other members were chosen by an extended consultative process with the aim of representing a broad range of expertise and opinion. Ulric Neisser
was was appointed Chair. Three of the experts were also among the 52 signatories to "Mainstream Science on Intelligence
", a similar though much shorter statement of expert opinion on intelligence research findings published in 1994. Members of BSA and BAPPI were asked to comment on a preliminary draft of the report. The entire Task Force gave unanimous support to the final report. An edited version of "Intelligence: Knowns and Unknowns" was published in the journal American Psychologist
in February 1996.
testing which was also by far the most widely used in practical settings. Intelligence quotient
(IQ) tests do correlate with one another and that the view that the general intelligence factor
(g) is a statistical artifact is a minority one. IQ scores are fairly stable during development in the sense that while a child reasoning ability increases, the child relative ranking in comparison to that of other individuals of the same age is fairly stable during development. The report stated that IQ scores measure important skills as they correlate fairly well (0.5) with grades. This implied that the explained variance (given certain linear assumptions) is 25%. "Wherever it has been studied, children with high scores on tests of intelligence tend to learn more of what is taught in school than their lower-scoring peers. There may be styles of teaching and methods of instruction that will decrease or increase this correlation, but none that consistently eliminates it has yet been found." IQ scores also correlated with school achievement tests designed to measure knowledge of the curriculum. Other personal characteristics affecting this may be persistence, interest in school, and willingness to study which may be influenced by the degree of encouragement for academic achievement a child receives and more general cultural factors. Test scores were the best single predictor of an individual's years of education. They were somewhat more important than social class as measured by occupation/education of parents.
IQ scores were also correlated (0.3-0.5) with various measures of job performance such as supervisor ratings and work samples. The correlations were higher when the unreliability of such measures were controlled for. IQ scores were sometimes described as the "best available predictor" of job performance. Intelligence test scores did correlate significantly with social status and income later in life. They were somewhat less important for this than parental SES although the effects of parental SES and IQ were hard to separate. IQ rests had lower negative correlations with certain socially undesirable outcomes such as that children with high IQ were less likely to engage in juvenile crime. One example being a study finding a correlation of -0.19 (-0.17 with social class controlled for) between IQ scores and number of juvenile offenses in a large Danish sample. This implied that the explained variance (given certain linear assumptions) is less than 4% for these negative outcomes.
While both genetic and environmental variables were involved in the manifestation of intelligence, the role of genetics had been shown to increase in importance with age. In particular, the effect of the family environment shared by all children in a family, while important in early childhood, became quite small (zero in some studies) by late adolescence. Why this occurs is unclear. One possibility is that people with different genes tend to seek out different environments that reinforce the effects of those genes. Nonetheless, there were several important environmental factors which were known to affect IQ, such as having received very poor or interrupted schooling. However, regarding interventions such as the Head Start Program and similar programs lasting one or two years, while producing initial IQ gains, these had disappeared by the end of elementary school, although there may be other benefits such as more likely to finish high school. The more intensive Abecedarian Project had produced more long-lasting gains. The report stated that a number of biological factors, including malnutrition, exposure to toxic substances, and various prenatal and perinatal factors, resulted in lowered IQ under at least some conditions. The much-discussed "Flynn effect
", which refers to the striking worldwide mean IQ increase over time, seemed too large to have simply reflected increased test sophistication. Possible explanations included improved nutrition and more complex environment. It was also unclear to what degree the IQ increase reflected real gain in intelligence.
programs).
Regarding sex differences so have most standard tests of intelligence been constructed to show equal results, but some studies show small differences. Males do better on visual-spatial tasks, with a particularly large difference on mental rotation (nearly 1 SD), which is significant for their generally better performance in tasks that involve aiming and throwing. Males also do relatively better on on tests of proportional and mechanical reasoning as well as on mathematics. Females do better on verbal tests and some memory tests. They do relatively better in tests of literature, English composition, Spanish, reading, and spelling. More males have dyslexia and stuttering. Possible causes include gender roles and differences in brain structure which in turn may be due genetics and/or environment. Differences in sex hormones may be another explanation. Female exposure to high levels of male hormones in utero
is associated with higher spatial abilities as well as more spatial ability as well as more play with "boys' toys" and less with 'girls' toys". Males with higher testosterone levels do better on visuo-spatial abilities and worse on verbal abilities. Older males given testosterone score better on visuo-spatial tests.
As the measured differences in average intelligence between various ethnic groups reflect complex patterns, no overall generalization about them was appropriate. Regarding Asian Americans, studies had shown slightly lower to slightly higher scores compared to White Americans. Average IQ in East Asian nations had been reported as equal to substantially above the American average. Asians did particularly well on spatial tests. Their knowledge of mathematics were above that predicted from IQ scores which may reflect cultural differences and/or higher spatial ability. Their occupational achievement were also higher than predicted by IQ scores with their occupational achievements more appropriate for an average IQ of 110-120. In addition to cultural factors, gene-based temperamental factor may also have been important.
Hispanics
scores typically were between those of Blacks and Whites. Linguistic factors may have been particularly important for this group with many not speaking English well or English not their first language. This may have been reflected in higher scores on performance than on verbal subtests. Nevertheless, for young children the WISC-R had reasonably high correlations with school achievement measures. Standard aptitude tests predicted first-year college grades about as well for Hispanic high school students with moderate to high English proficiency as they did for non Hispanic Whites.
Native American
s were culturally and linguistically diverse as well as living in widely varying settings. Groups, like the Inuit, who lived in the arctic tended to do particularly well, with no substantial sex difference, on visual-spatial skills. The likely represented a genetic and/or learned adoption to the difficult arctic environment. Many Indian children suffered from chronic middle-ear infection and hearing loss can have marked negative effects on verbal tests. This may have been related to the relatively lower verbal scores for this group.
There was a long-standing 15 point or 1 SD difference between the intelligence test scores of African American
s and White American
s, though it might have narrowed slightly in the then recent years. The difference was largest on those tests, verbal or non-verbal, that best represented the general intelligence factor
(g). Controlled studies of the way the tests were formulated and administered had shown that this did not contribute substantially to the difference. Attempts to devise tests that would minimize disadvantages of this kind had been unsuccessful. The scores predicted future achievement equally well for blacks and whites. "The cause of that differential is not known; it is apparently not due to any simple form of bias in the content or administration of the tests themselves. The Flynn effect shows that environmental factors can produce differences of at least this magnitude, but that effect is mysterious in its own right. Several culturally based explanations of the Black/ White IQ differential have been proposed; some are plausible, but so far none has been conclusively supported. There is even less empirical support for a genetic interpretation. In short, no adequate explanation of the differential between the IQ means of Blacks and Whites is presently available."
* = Mainstream Science on Intelligence
signatory
magazine Frank Miele
interviewed psychologist Arthur Jensen
about the public and academic reception of his work and how he interpreted the APA task force's summary dismissal of one of the main tenets of Jensen's own position, i.e. that genetics play a significant role in the appearance of between-group differences in IQ. Jensen responded:
American Psychological Association
The American Psychological Association is the largest scientific and professional organization of psychologists in the United States. It is the world's largest association of psychologists with around 154,000 members including scientists, educators, clinicians, consultants and students. The APA...
.
Background
The Board of Scientific Affairs (BSA) of the American Psychological AssociationAmerican Psychological Association
The American Psychological Association is the largest scientific and professional organization of psychologists in the United States. It is the world's largest association of psychologists with around 154,000 members including scientists, educators, clinicians, consultants and students. The APA...
had concluded that after the publication of The Bell Curve
The Bell Curve
The Bell Curve is a best-selling and controversial 1994 book by the Harvard psychologist Richard J. Herrnstein and political scientist Charles Murray...
(1994) and the following debate that there were "serious misunderstandings" and "that there was urgent need for an authoritative report on these issues—one that all sides could use as a basis for discussion". Furthermore, "Another unfortunate aspect of the debate was that many participants made little effort to distinguish scientific issues from political ones, Research findings were often assessed not so much on their merits or their scientific standing as on their supposed political implications." The report stated that "The charge to our Task Force was to prepare a dispassionate survey of the state of the art: to make clear what has been scientifically established, what is presently in dispute, and what is still unknown. In fulfilling that charge, the only recommendations we shall make are for further research and calmer debate."
It was originally published on August 7, 1995. It was authored by a task force of 11 experts. The APA Board on the Advancement of Psychology in the Public Interest (BAPPI) nominated one member of the Task Force. The Committee on Psychological Tests and Assessment nominated another. A third was nominated by the Council of Representatives. The other members were chosen by an extended consultative process with the aim of representing a broad range of expertise and opinion. Ulric Neisser
Ulric Neisser
Ulric Neisser is an American psychologist and member of the National Academy of Sciences. He is a faculty member at Cornell University. In 1995, he headed an American Psychological Association task force that reviewed The Bell Curve and related controversies in the study of intelligence. The task...
was was appointed Chair. Three of the experts were also among the 52 signatories to "Mainstream Science on Intelligence
Mainstream Science on Intelligence
Mainstream Science on Intelligence was a public statement issued by a group of academic researchers in fields allied to intelligence testing that claimed to present those findings widely accepted in the expert community...
", a similar though much shorter statement of expert opinion on intelligence research findings published in 1994. Members of BSA and BAPPI were asked to comment on a preliminary draft of the report. The entire Task Force gave unanimous support to the final report. An edited version of "Intelligence: Knowns and Unknowns" was published in the journal American Psychologist
American Psychologist
The American Psychologist is the official academic journal of the American Psychological Association. It contains archival documents and articles covering current issues in psychology, the science and practice of psychology, and psychology's contribution to public policy...
in February 1996.
Findings
"Intelligence: Knowns and Unknowns" stated that many different theories of intelligence have been proposed. Many questions were still unanswered. Most research had been done on psychometricPsychometrics
Psychometrics is the field of study concerned with the theory and technique of psychological measurement, which includes the measurement of knowledge, abilities, attitudes, personality traits, and educational measurement...
testing which was also by far the most widely used in practical settings. Intelligence quotient
Intelligence quotient
An intelligence quotient, or IQ, is a score derived from one of several different standardized tests designed to assess intelligence. When modern IQ tests are constructed, the mean score within an age group is set to 100 and the standard deviation to 15...
(IQ) tests do correlate with one another and that the view that the general intelligence factor
General intelligence factor
The g factor, where g stands for general intelligence, is a statistic used in psychometrics to model the mental ability underlying results of various tests of cognitive ability...
(g) is a statistical artifact is a minority one. IQ scores are fairly stable during development in the sense that while a child reasoning ability increases, the child relative ranking in comparison to that of other individuals of the same age is fairly stable during development. The report stated that IQ scores measure important skills as they correlate fairly well (0.5) with grades. This implied that the explained variance (given certain linear assumptions) is 25%. "Wherever it has been studied, children with high scores on tests of intelligence tend to learn more of what is taught in school than their lower-scoring peers. There may be styles of teaching and methods of instruction that will decrease or increase this correlation, but none that consistently eliminates it has yet been found." IQ scores also correlated with school achievement tests designed to measure knowledge of the curriculum. Other personal characteristics affecting this may be persistence, interest in school, and willingness to study which may be influenced by the degree of encouragement for academic achievement a child receives and more general cultural factors. Test scores were the best single predictor of an individual's years of education. They were somewhat more important than social class as measured by occupation/education of parents.
IQ scores were also correlated (0.3-0.5) with various measures of job performance such as supervisor ratings and work samples. The correlations were higher when the unreliability of such measures were controlled for. IQ scores were sometimes described as the "best available predictor" of job performance. Intelligence test scores did correlate significantly with social status and income later in life. They were somewhat less important for this than parental SES although the effects of parental SES and IQ were hard to separate. IQ rests had lower negative correlations with certain socially undesirable outcomes such as that children with high IQ were less likely to engage in juvenile crime. One example being a study finding a correlation of -0.19 (-0.17 with social class controlled for) between IQ scores and number of juvenile offenses in a large Danish sample. This implied that the explained variance (given certain linear assumptions) is less than 4% for these negative outcomes.
While both genetic and environmental variables were involved in the manifestation of intelligence, the role of genetics had been shown to increase in importance with age. In particular, the effect of the family environment shared by all children in a family, while important in early childhood, became quite small (zero in some studies) by late adolescence. Why this occurs is unclear. One possibility is that people with different genes tend to seek out different environments that reinforce the effects of those genes. Nonetheless, there were several important environmental factors which were known to affect IQ, such as having received very poor or interrupted schooling. However, regarding interventions such as the Head Start Program and similar programs lasting one or two years, while producing initial IQ gains, these had disappeared by the end of elementary school, although there may be other benefits such as more likely to finish high school. The more intensive Abecedarian Project had produced more long-lasting gains. The report stated that a number of biological factors, including malnutrition, exposure to toxic substances, and various prenatal and perinatal factors, resulted in lowered IQ under at least some conditions. The much-discussed "Flynn effect
Flynn effect
The Flynn effect is the name given to a substantial and long-sustained increase in intelligence test scores measured in many parts of the world. When intelligence quotient tests are initially standardized using a sample of test-takers, by convention the average of the test results is set to 100...
", which refers to the striking worldwide mean IQ increase over time, seemed too large to have simply reflected increased test sophistication. Possible explanations included improved nutrition and more complex environment. It was also unclear to what degree the IQ increase reflected real gain in intelligence.
Group differences
The report states that group differences in intelligence continue to be the subject of intense interest and debate. Reasons include social, psychological, political, and legal (including the need for and effectiveness of affirmative actionAffirmative action
Affirmative action refers to policies that take factors including "race, color, religion, gender, sexual orientation or national origin" into consideration in order to benefit an underrepresented group, usually as a means to counter the effects of a history of discrimination.-Origins:The term...
programs).
Regarding sex differences so have most standard tests of intelligence been constructed to show equal results, but some studies show small differences. Males do better on visual-spatial tasks, with a particularly large difference on mental rotation (nearly 1 SD), which is significant for their generally better performance in tasks that involve aiming and throwing. Males also do relatively better on on tests of proportional and mechanical reasoning as well as on mathematics. Females do better on verbal tests and some memory tests. They do relatively better in tests of literature, English composition, Spanish, reading, and spelling. More males have dyslexia and stuttering. Possible causes include gender roles and differences in brain structure which in turn may be due genetics and/or environment. Differences in sex hormones may be another explanation. Female exposure to high levels of male hormones in utero
In utero
In utero is a Latin term literally meaning "in the womb". In biology, the phrase describes the state of an embryo or fetus. In legal contexts, the phrase is used to refer to unborn children. Under common law, unborn children are still considered to exist for property transfer purposes.-See also:*...
is associated with higher spatial abilities as well as more spatial ability as well as more play with "boys' toys" and less with 'girls' toys". Males with higher testosterone levels do better on visuo-spatial abilities and worse on verbal abilities. Older males given testosterone score better on visuo-spatial tests.
As the measured differences in average intelligence between various ethnic groups reflect complex patterns, no overall generalization about them was appropriate. Regarding Asian Americans, studies had shown slightly lower to slightly higher scores compared to White Americans. Average IQ in East Asian nations had been reported as equal to substantially above the American average. Asians did particularly well on spatial tests. Their knowledge of mathematics were above that predicted from IQ scores which may reflect cultural differences and/or higher spatial ability. Their occupational achievement were also higher than predicted by IQ scores with their occupational achievements more appropriate for an average IQ of 110-120. In addition to cultural factors, gene-based temperamental factor may also have been important.
Hispanics
Hispanic and Latino Americans
Hispanic or Latino Americans are Americans with origins in the Hispanic countries of Latin America or in Spain, and in general all persons in the United States who self-identify as Hispanic or Latino.1990 Census of Population and Housing: A self-designated classification for people whose origins...
scores typically were between those of Blacks and Whites. Linguistic factors may have been particularly important for this group with many not speaking English well or English not their first language. This may have been reflected in higher scores on performance than on verbal subtests. Nevertheless, for young children the WISC-R had reasonably high correlations with school achievement measures. Standard aptitude tests predicted first-year college grades about as well for Hispanic high school students with moderate to high English proficiency as they did for non Hispanic Whites.
Native American
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
s were culturally and linguistically diverse as well as living in widely varying settings. Groups, like the Inuit, who lived in the arctic tended to do particularly well, with no substantial sex difference, on visual-spatial skills. The likely represented a genetic and/or learned adoption to the difficult arctic environment. Many Indian children suffered from chronic middle-ear infection and hearing loss can have marked negative effects on verbal tests. This may have been related to the relatively lower verbal scores for this group.
There was a long-standing 15 point or 1 SD difference between the intelligence test scores of African American
African American
African Americans are citizens or residents of the United States who have at least partial ancestry from any of the native populations of Sub-Saharan Africa and are the direct descendants of enslaved Africans within the boundaries of the present United States...
s and White American
White American
White Americans are people of the United States who are considered or consider themselves White. The United States Census Bureau defines White people as those "having origins in any of the original peoples of Europe, the Middle East, or North Africa...
s, though it might have narrowed slightly in the then recent years. The difference was largest on those tests, verbal or non-verbal, that best represented the general intelligence factor
General intelligence factor
The g factor, where g stands for general intelligence, is a statistic used in psychometrics to model the mental ability underlying results of various tests of cognitive ability...
(g). Controlled studies of the way the tests were formulated and administered had shown that this did not contribute substantially to the difference. Attempts to devise tests that would minimize disadvantages of this kind had been unsuccessful. The scores predicted future achievement equally well for blacks and whites. "The cause of that differential is not known; it is apparently not due to any simple form of bias in the content or administration of the tests themselves. The Flynn effect shows that environmental factors can produce differences of at least this magnitude, but that effect is mysterious in its own right. Several culturally based explanations of the Black/ White IQ differential have been proposed; some are plausible, but so far none has been conclusively supported. There is even less empirical support for a genetic interpretation. In short, no adequate explanation of the differential between the IQ means of Blacks and Whites is presently available."
Members of the Task Force
- Ulric NeisserUlric NeisserUlric Neisser is an American psychologist and member of the National Academy of Sciences. He is a faculty member at Cornell University. In 1995, he headed an American Psychological Association task force that reviewed The Bell Curve and related controversies in the study of intelligence. The task...
(Chair), Emory UniversityEmory UniversityEmory University is a private research university in metropolitan Atlanta, located in the Druid Hills section of unincorporated DeKalb County, Georgia, United States. The university was founded as Emory College in 1836 in Oxford, Georgia by a small group of Methodists and was named in honor of... - Gwyneth BoodooGwyneth BoodooGwyneth M. Boodoo is an American psychologist and expert on educational measurement.Boodoo received her doctorate in educational measurement from the University of Toronto in 1978...
, Educational Testing ServiceEducational Testing ServiceEducational Testing Service , founded in 1947, is the world's largest private nonprofit educational testing and assessment organization... - Thomas J. Bouchard, Jr.*, University of MinnesotaUniversity of MinnesotaThe University of Minnesota, Twin Cities is a public research university located in Minneapolis and St. Paul, Minnesota, United States. It is the oldest and largest part of the University of Minnesota system and has the fourth-largest main campus student body in the United States, with 52,557...
- A. Wade BoykinA. Wade BoykinA. Wade Boykin is an American psychology professor known for his work in the field of education. He is currently member of the faculty of Howard University.Boykin is Director of the Developmental Psychology Graduate Program at Howard University...
, Howard UniversityHoward UniversityHoward University is a federally chartered, non-profit, private, coeducational, nonsectarian, historically black university located in Washington, D.C., United States... - Nathan BrodyNathan BrodyNathan Brody is an American psychology professor Emeritus known for his work on intelligence and personality.Brody received his BA from University Of New Hampshire and his MA and PhD from University of Michigan...
, Wesleyan UniversityWesleyan UniversityWesleyan University is a private liberal arts college founded in 1831 and located in Middletown, Connecticut. According to the Carnegie Foundation for the Advancement of Teaching, Wesleyan is the only Baccalaureate College in the nation that emphasizes undergraduate instruction in the arts and... - Stephen J. CeciStephen J. CeciStephen J. Ceci is an American psychologist at Cornell University. He studies the accuracy of children's courtroom testimony , and he is an expert in the development of intelligence and memory...
, Cornell UniversityCornell UniversityCornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...
- Diane F. HalpernDiane F. HalpernDiane F. Halpern is an American psychologist and past-president of the American Psychological Association .Halpern received her B.A. from University of Pennsylvania and an M.A. from Temple University. She then received an M.A., from University of Cincinnati, followed by a Ph.D. from that...
, California State University, San BernardinoCalifornia State University, San BernardinoCalifornia State University, San Bernardino, also known as Cal State San Bernardino or CSUSB is a public research university and one of the twenty three general campuses of the California State University system. The main campus sits on in the suburban University District of , United States, with... - John C. LoehlinJohn C. LoehlinJohn Clinton Loehlin is an American behavior geneticist and psychology and computer science professor emeritus. Loehlin has served as president of the Behavior Genetics Association and of the Society for Multivariate Experimental Psychology....
*, University of Texas, Austin - Robert PerloffRobert PerloffRobert Perloff is an American psychology and business administration professor emeritus.Born and raised in Philadelphia, Perloff was drafted into the United States Army to fight in the Philippines during World War II...
*, University of PittsburghUniversity of PittsburghThe University of Pittsburgh, commonly referred to as Pitt, is a state-related research university located in Pittsburgh, Pennsylvania, United States. Founded as Pittsburgh Academy in 1787 on what was then the American frontier, Pitt is one of the oldest continuously chartered institutions of... - Robert J. Sternberg, Yale UniversityYale UniversityYale University is a private, Ivy League university located in New Haven, Connecticut, United States. Founded in 1701 in the Colony of Connecticut, the university is the third-oldest institution of higher education in the United States...
- Susana UrbinaSusana UrbinaSusana Urbina is a Peruvian-American psychologist. She received her Ph.D. in Psychometrics from Fordham University in 1972 and was licensed in Florida in 1976...
, University of North FloridaUniversity of North FloridaThe University of North Florida is a public university located in Jacksonville, Florida. A member institution of the State University System of Florida, the university is accredited by the Commission on Colleges of the Southern Association of Colleges and Schools to award baccalaureate, master’s...
Mainstream Science on Intelligence
Mainstream Science on Intelligence was a public statement issued by a group of academic researchers in fields allied to intelligence testing that claimed to present those findings widely accepted in the expert community...
signatory
Reception
In 2002, senior editor of SkepticSkeptic (U.S. magazine)
Skeptic is a quarterly science education and science advocacy magazine published internationally by The Skeptics Society, a nonprofit organization devoted to promoting scientific skepticism and resisting the spread of pseudoscience, superstition, and irrational beliefs...
magazine Frank Miele
Frank Miele
Frank Miele is an American journalist and senior editor at Skeptic. He is best known for his controversial advocacy of hereditarian hypotheses about race, especially race and intelligence....
interviewed psychologist Arthur Jensen
Arthur Jensen
Arthur Robert Jensen is a Professor Emeritus of educational psychology at the University of California, Berkeley. Jensen is known for his work in psychometrics and differential psychology, which is concerned with how and why individuals differ behaviorally from one another.He is a major proponent...
about the public and academic reception of his work and how he interpreted the APA task force's summary dismissal of one of the main tenets of Jensen's own position, i.e. that genetics play a significant role in the appearance of between-group differences in IQ. Jensen responded:
See also
- History of the race and intelligence controversyHistory of the race and intelligence controversyThe history of the race and intelligence controversy concerns the historical development of a debate, primarily in the United States, concerning possible explanations of group differences in intelligence...
- Race and intelligenceRace and intelligenceThe connection between race and intelligence has been a subject of debate in both popular science and academic research since the inception of intelligence testing in the early 20th century...
- Mainstream Science on IntelligenceMainstream Science on IntelligenceMainstream Science on Intelligence was a public statement issued by a group of academic researchers in fields allied to intelligence testing that claimed to present those findings widely accepted in the expert community...
(1994)