Are they connected?
Abstract:
Wilkinson contends that economic inequality reduces the health and life expectancy of the whole population but his argument does not make sense within its own evolutionary framework.
Recent evolutionary psychological theory suggests that the human brain, adapted to the ancestral environment, has difficulty comprehending and dealing with entities and situations that did not exist in the ancestral environment and that general intelligence evolved as a domain-specific adaptation to solve evolutionarily novel problems.
Since most dangers to health in the contemporary society are evolutionarily novel, it follows that more intelligent individuals are better able to recognize and deal with such dangers and live longer.
Consistent with the theory, the macro-level analyses show that income inequality and economic development have no effect on life expectancy at birth, infant mortality and age-specific mortality net of average intelligence quotient (IQ) in 126 countries.
They also show that an average IQ has a very large and significant effect on population health but not in the evolutionarily familiar sub-Saharan Africa. At the micro level, the General Social Survey data show that, while both income and intelligence have independent positive effects on self-reported health, intelligence has a stronger effect than income.
The data collectively suggest that individuals in wealthier and more egalitarian societies live longer and stay healthier, not because they are wealthier or more egalitarian but because they are more intelligent. No way!
Document Type: Research article
DOI: 10.1348/135910705X69842
Affiliations: 1: Interdisciplinary Institute of Management, London School of Economics and Political Science, UK
Dear Ms Gibson of London School of Economics:
Re: It is not IQ It is the biological and physical environment Stupid! That impacts the health of nations.
I read with interest and some level of disgust by the assumption of IQ as defined by Western Culture to define the competence of Africans and especially Ethiopians as mentioned in this article.
I would like to challenge the Cultural and Competency IQ of the author of this rather ridiculous and racist author. We should question the integrity and implication of such rather depressing and outmoded research and generalizations.
Imagine an Ethiopian High School Student administering a literature IQ test to all the Nobel Literature laureates on Quine and Semina Work in Amharic and in Geez even better and assessing their Quine IQ status.
I am sure all of them will score 00.00 let alone this rather racist and demented Eco-psychologist of the LSE will surface on the Quine IQ square. Just imagine the class discussion on a paper presented by such Ethiopian High School student on the performance of Western Noble laureates of literature. This is the analogy of this rather disturbing paper presented to us.
If you then gave the same Geez or Amharic Quine IQ test to the rest of the world and mapped the Quine IQ you will be shocked to realize that world IQ may not even reach 1% and that will be a tragedy. In effect, this is the tragedy of this paper.
I am a physician and public health scientist who have studied child development (physical and cognitive development) and evaluated research material on child survival across developing an developed countries for the past 25 years. My MPH thesis was on "Evaluating Mother and Child Health Services in Developing and Developed countries with a focus on Perinatal Survival of children in developing and developed countries.
My research indicates that child survival is dependent on two key determinants, both relevant to the situation of the mother. Biological marker of maternal birth weight that is also dependent on the pool of matriarchal birth weights for generations. This in effect defines the genetic pool reserve as well as the weight and gestation of the pregnancy at birth.
The second critical issue is environmental and behavioral and that is the educational status of the mother. This education could be cultural, environmental and empirical as it relates to the survival of the child.
This in effect means a well adjusted and educated mother will ensure the survival of her offspring by either ensuring her own socio-economic and cultural environment by either producing the appropriate environments or by organizing the environment around her for the child to succeed and survive.
Where cultural or empirical IQ will really matters is on the social and economic paradigm more than the biological environment.
That is why it is commonly said that: “If you educate a man, you educate one person; but if you educate a woman, you educate a family, the home, the community and the nation at large. If you educate both then hey can educate the world!
It is clear that a child born in Africa has more opportunities for challenging immunological experiences than a child born in Europe or North America. Talk to Madonna who is not a scientist but has definitely a much higher IQ than your author about the chances of the survival of her newly adopted Malawian son.
The African environment is hostile as it is very conducive to the survival of micro-organisms that are pathogenic to humans than it is in the temperate climate. We now know in current medical research almost all diseases are associated with the competence of our immune system' s ability to differentiate between self and non self.
Infections manifest themselves in many forms and most of the Cardiovascular and chronic diseases including cancers are closely associated with our body's response to viral and other microbial infections.
This is true of Cancer of the Stomach, Peptic Acid Disease, Cardio-vascular accidents and even degenerative disorders. Science is giving us the opportunity to identify the inter-relatedness of most chronic conditions and our immune system's competency.
Our immune system is challenged by more infectious conditions in Developing and temperate climates that makes us all susceptible for continuous challenges to our immune system's response to infections and stressors in life.
In short, it is the biological and physical environment that is more critical than the IQ as suggested by your author. After all, if the Massai in Africa were to define IQ in the sense of their ability to survive in the wilds of Africa, most so called geniuses of the West and noble laureates will not last for long.
So, does that mean the noble scientists have a diminishing Massai defined IQ and as such will have a short survival and quality of life in the Massai world?
Surely, this is a highly erroneous and rather racist research and you should allow alternative perspectives to be explored before you sensationalize such highly controversial research findings.
Remember! Health is not the mere absence of disease, disability and injury, but, the comprehensive wellbeing of the spiritual, emotional, psychological and physical wellbeing of an individual and the community at large. Within this larger construct, the IQ has little to do with health as much as the environment and how our system adopts to it.
All the same, I believe all human beings given the opportunity have the capacity to adopt to new skills, new challenges and opportunities, may be some faster than others but with diverse context and depth and competency.
The question is not IQ, it is rather the hostile environment at home, school, work and leisure that stresses our immune system to such an extent that our whole system collapses in the end. Even geriatric changes are now been associated to our immune system's capacity to adjust with changing age, gender, emotional and physical stressful life events we all face in our life time.
This is not yet complete science and we need to observe and expand research to understand our own body and how we adopt to changing life events.
I request your department which I believe is an Economics center to look at how education and IQ impacts wealth creation rather than delving in highly unscientific association of IQ and health.
It is the environment stupid, more than the IQ that determines our health outcome!
Having said that, nurture or nature is part of the same universe, why bother!
I trust you will consider this contribution as you make future research and line of enquiry to follow us the recent publication in your department.
Please do not hesitate to contact me if I can be helpful. Thanking you for your attention to this matter, I remain;
Yours sincerely
Belai Habte-Jesus, MD, MPH
Global Strategic Enterprises, Inc;03.933.8737; globalbelai@hotmail.com
Intelligence quotient
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"IQ" redirects here. For other uses, see IQ (disambiguation).
IQ tests are designed to give approximately this Gaussian distribution. Colors delineate one standard deviation.
An intelligence quotient or IQ is a score derived from a set of standardized tests of intelligence. Intelligence tests come in many forms, and some tests use a single type of item or question. Most tests yield both an overall score and individual subtest scores. Regardless of design, all IQ tests attempt to measure the same general intelligence.[1] Component tests are generally designed and selected because they are found to be predictive of later intellectual development, such as educational achievement.
IQ also correlates with job performance, socioeconomic advancement, and "social pathologies". Recent work has demonstrated links between IQ and health, longevity, and functional literacy. [2] [3] However, IQ tests do not measure all meanings of "intelligence", such as creativity. IQ scores are relative (like placement in a race), not absolute (like the measurement of a ruler).
For people living in the prevailing conditions of the developed world, IQ is highly heritable, and by adulthood the influence of family environment on IQ is undetectable. That is, significant variation in IQ between adults can be attributed to genetic variation, with the remaining variation attributable to environmental sources that are not shared within families. In the United States, marked variation in IQ occurs within families, with siblings differing on average by almost one standard deviation.
The average IQ scores for many populations were rising during the 20th century: a phenomenon called the Flynn effect. It is not known whether these changes in scores reflect real changes in intellectual abilities. On average, IQ scores are stable over a person's lifetime, but some individuals undergo large changes. For example, scores can be affected by the presence of learning disabilities.
Contents
[hide]
• 1 The definition of the IQ
• 2 Components of intelligence
• 3 History
• 4 IQ and general intelligence factor
• 5 Genetics versus environment
o 5.1 Environment
o 5.2 Development
o 5.3 Mental retardation
o 5.4 IQ, education, and income
o 5.5 Regression
• 6 IQ and the brain
o 6.1 Brain size and IQ
o 6.2 Brain areas associated with IQ
o 6.3 Brain structure and IQ
• 7 The Flynn effect
• 8 Group differences
o 8.1 Sex and intelligence
o 8.2 Race and IQ
o 8.3 Health and IQ
o 8.4 Wealth and IQ
• 9 Practical validity
• 10 Public policy
o 10.1 Use of IQ in the United States legal system
• 11 Validity and g-loading of specific tests
• 12 Controversy
o 12.1 Social construct
o 12.2 The Mismeasure of Man
o 12.3 The view of the American Psychological Association
o 12.4 IQ test
• 13 Notes
• 14 See also
• 15 References
• 16 External links
o 16.1 Collective statements
o 16.2 Review papers
o 16.3 Professional Intelligence Testing
[edit] The definition of the IQ
Originally, IQ was calculated with the formula
A 10-year-old who scored as high as the average 13-year-old, for example, would have an IQ of 130 (100*13/10).
Because this formula only worked for children, it was replaced by a projection of the measured rank on the Gaussian bell curve with a center value (average IQ) of 100, and a standard deviation of 15 or occasionally 16.
[edit] Components of intelligence
Component tests are generally designed and selected because they are found to be predictive of later intellectual development, such as educational achievement. IQ also correlates with job performance, socioeconomic advancement, and, usually negatively, with "social pathologies".
Recent work has demonstrated links between IQ and health, longevity, and functional literacy. [4] [5] However, IQ tests do not measure all meanings of "intelligence", such as creativity. IQ scores are relative (like placement in a race), not absolute (like the measurement of a ruler).
For people living in the prevailing conditions of the developed world, IQ is highly heritable, and by adulthood the influence of family environment on IQ is undetectable. That is, significant variation in IQ between adults can be attributed to genetic variation, with the remaining variation attributable to environmental sources that are not shared within families. In the United States, marked variation in IQ occurs within families, with siblings differing on average by almost one standard deviation.
The average IQ scores for many populations were rising during the 20th century: a phenomenon called the Flynn effect. It is not known whether these changes in scores reflect real changes in intellectual abilities. On average, IQ scores are stable over a person's lifetime, but some individuals undergo large changes. For example, scores can be affected by the presence of learning disabilities.
[edit] History
In 1905, the French psychologist Alfred Binet published the first modern intelligence test, the Binet-Simon intelligence scale.
His principal goal was to identify students who needed special help in coping with the school curriculum. Along with his collaborator Theodore Simon, Binet published revisions of his intelligence scale in 1908 and 1911, the last appearing just before his untimely death. In 1912, the abbreviation of "intelligence quotient" or I.Q., a translation of the German Intelligenz-Quotient, was coined by the German psychologist William Stern.
A further refinement of the Binet-Simon scale was published in 1916 by Lewis M. Terman, from Stanford University, who incorporated Stern's proposal that an individual's intelligence level be measured as an intelligence quotient (I.Q.). Terman's test, which he named the Stanford-Binet Intelligence Scale formed the basis for one of the modern intelligence tests still commonly used today. They are all colloquially known as IQ tests.
[edit] IQ and general intelligence factor
Main article: General intelligence factor
Modern IQ tests produce scores for different areas (e.g., language fluency, three-dimensional thinking, etc.), with the summary score calculated from subtest scores. The average score, according to the bell curve, is 100. Individual subtest scores tend to correlate with one another, even when seemingly disparate in content.
Analysis of individuals' scores on the subtests of a single IQ test or the scores from a variety of different IQ tests (e.g., Stanford-Binet, WISC-R, Raven's Progressive Matrices, Cattell Culture Fair III, Universal Nonverbal Intelligence Test, and others) reveal that they all measure a single common factor and various factors that are specific to each test. This kind of factor analysis has led to the theory that underlying these disparate cognitive tasks is a single factor, termed the general intelligence factor (or g), that corresponds with the common-sense concept of intelligence. In the normal population, g and IQ are roughly 90% correlated and are often used interchangeably.
Various IQ tests measure a standard deviation with different number of points. Thus, when an IQ score is stated, the standard deviation used should also be stated. A result of 124 in a test with a 24-point standard deviation corresponds to a score of 115 in a test with a 15-point deviation. [6]
Where an individual has scores that do not correlate with each other, there is a good reason to look for a learning disability or other cause for the lack of correlation. Tests have been chosen for inclusion because they display the ability to use this method to predict later difficulties in learning.
[edit] Genetics versus environment
Main article: Inheritance of intelligence
The role of genes and environment (nature vs. nurture) in determining IQ is reviewed in Plomin et al. (2001, 2003). The degree to which genetic variation contributes to observed variation in a trait is measured by a statistic called heritability.
Heritability scores range from 0 to 1, and can be interpreted as the percentage of variation (e.g. in IQ) that is due to variation in genes. Twins studies and adoption studies are commonly used to determine the heritability of a trait. Until recently heritability was mostly studied in children. Some studies find the heritability of IQ around 0.5 but the studies show ranges from 0.4 to 0.8;[7] that is, depending on the study, a little less than half to substantially more than half of the variation in IQ among the children studied was due to variation in their genes. The remainder was thus due to environmental variation and measurement error.
A heritability in the range of 0.4 to 0.8 implies that IQ is "substantially" heritable. Studies with adults show that they have a higher heritability of IQ than children do and that heritability could be as high as 0.8.
The American Psychological Association's 1995 task force on "Intelligence: Knowns and Unknowns" concluded that within the white population the heritability of IQ is "around .75" (p. 85). [8] The Minnesota Study of Twins Reared Apart, a multiyear study of 100 sets of reared apart twins which was started in 1979, concluded that about 70% of the variance in IQ was found to be associated with genetic variation. [9]
The heritability of IQ has been tested on large numbers of twins, siblings, parent-child relationships, and adoptees. Evidence from family studies provides the main supporting evidence from which arguments about the relative roles of genetics and environment are constructed. Put all these studies together, which include the IQ tests of tens of thousands of individuals, and the table looks like this[citation needed]:
Percent Correlation of IQ Tests
Relationship Correlation
The same person tested twice 87%
Identical twins reared together 86%
Identical twins reared apart 76%
Fraternal twins reared together 55%
Biological siblings 47%
Parents and children living together 40%
Parents and children living apart 31%
Adopted children living together 0%
Unrelated people living apart 0%
[edit] Environment
Environmental factors play a major role in determining IQ in extreme situations. Proper childhood nutrition appears critical for cognitive development; malnutrition can lower IQ. Other research indicates environmental factors such as prenatal exposure to toxins, duration of breastfeeding [citation needed], and micronutrient deficiency can affect IQ. In the developed world, there are some family effects on the IQ of children, accounting for up to a quarter of the variance. However, by adulthood, this correlation disappears, so that the IQ of adults living in the prevailing conditions of the developed world may be more heritable.
Nearly all personality traits show that, contrary to expectations, environmental effects actually cause adoptive siblings raised in the same family to be as different as children raised in different families (Harris, 1998; Plomin & Daniels, 1987). Put another way, shared environmental variation for personality is zero, and all environmental effects would be nonshared.
Conversely, IQ is actually an exception to this, at least among children. The IQs of adoptive siblings, who share no genetic relation but do share a common family environment, are correlated at .32. Despite attempts to isolate them, the factors that cause adoptive siblings to be similar have not been identified. However, as explained below, shared family effects on IQ disappear after adolescence.
Active genotype-environment correlation, also called the "nature of nurture", is observed for IQ. This phenomenon is measured similarly to heritability; but instead of measuring variation in IQ due to genes, variation in environment due to genes is determined. One study found that 40% of variation in measures of home environment are accounted for by genetic variation. This suggests that the way human beings craft their environment is due in part to genetic influences.
A study of French children adopted between the ages of 4 and 6 shows the continuing interplay of nature and nurture. The children came from poor backgrounds with I.Q.’s that initially averaged 77, putting them near retardation. Nine years later after adoption, they retook the I.Q. tests, and all of them did better. The amount they improved was directly related to the adopting family’s status. "Children adopted by farmers and laborers had average I.Q. scores of 85.5; those placed with middle-class families had average scores of 92.
The average I.Q. scores of youngsters placed in well-to-do homes climbed more than 20 points, to 98." [10] This study suggests that IQ is not stable over the course of ones lifetime and that, even in later childhood, a change in environment can have a significant effect on IQ.
It is well known that it is possible to increase ones IQ score by training, for example by regulary playing puzzle games. Recent studies have shown that training ones working memory may increase IQ. (Klingberg et al., 2002)
[edit] Development
It is reasonable to expect that genetic influences on traits like IQ should become less important as one gains experiences with age. Surprisingly, the opposite occurs. Heritability measures in infancy are as low as 20%, around 40% in middle childhood, and as high as 80% in adulthood.[11]
Shared family effects also seem to disappear by adulthood. Adoption studies show that, after adolescence, adopted siblings are no more similar in IQ than strangers (IQ correlation near zero), while full siblings show an IQ correlation of 0.6. Twin studies reinforce this pattern: monozygotic (identical) twins raised separately are highly similar in IQ (0.86), more so than dizygotic (fraternal) twins raised together (0.6) and much more than adopted siblings (~0.0).[12]
Most of the IQ studies described above were conducted in developed countries, such as the United States, Japan, and Western Europe. Also, a few studies have been conducted in Moscow, East Germany, and India, and those studies have produced similar results.
Any such investigation is limited to describing the genetic and environmental variation found within the populations studied. This is a caveat of any heritability study.[citation needed]. Another caveat is that people with chromosomal abnormalities - such as klinefelter's syndrome and Triple X syndrome, will score considerably higher than the normal population without the chromosomal abnormalities, when scored against visual IQ tests, not IQ tests that have been tailored to measure IQ against the normal population.[13]
[edit] Mental retardation
About 75–80 percent of mental retardation is familial (runs in the family), and 20–25 percent is due to biological problems, such as chromosomal abnormalities or brain damage. [14] Mild to severe mental retardation is a symptom of several hundred single-gene disorders and many chromosomal abnormalities, including small deletions. Based on twin studies, moderate to severe mental retardation does not appear to be familial, but mild mental retardation does. That is, the relatives of the moderate to severely mentally retarded have normal ranges of IQs, whereas the families of the mildly mentally retarded have lower IQs.
IQ score ranges (from DSM-IV):
• mild mental retardation: IQ 50–55 to 70; children require mild support; formally called "Educable Mentally Retarded".
• moderate retardation: IQ 35–40 to 50–55; children require moderate supervision and assistance; formally called "Trainable Mentally Retarded".
• severe mental retardation: IQ 20–25 to 35–40; can be taught basic life skills and simple tasks with supervision.
• profound mental retardation: IQ below 20–25; usually caused by a neurological condition; require constant care.
The rate of mental retardation is higher among males than females, according to a 1991 U.S. Centers for Disease Control and Prevention (CDC) study. [15] This is aggravated by the fact that males, unlike females, do not have a spare X chromosome to offset chromosomal defects.
Individuals with IQs below 70 have been essentially exempted from the death penalty in the U.S. since 2002. [16]
[edit] IQ, education, and income
Tambs et al. (1989) found that occupational status, educational attainment, and IQ are individually heritable; and further found that "genetic variance influencing educational attainment … contributed approximately one-fourth of the genetic variance for occupational status and nearly half the genetic variance for IQ". In a sample of U.S. siblings, Rowe et al. (1997) report that the inequality in education and income was predominantly due to genes, with shared environmental factors playing a subordinate role.
[edit] Regression
The heritability of IQ measures the extent to which the IQ of children appears to be influenced by the IQ of parents. Because the heritability of IQ is less than 100%, the IQ of children tends to "regress" towards the mean IQ of the population. That is, high IQ parents tend to have children who are less bright than their parents, whereas low IQ parents tend to have children who are brighter than their parents. The effect can be quantified by the equation where
• is the predicted average IQ of the children;
• is the mean IQ of the population to which the parents belong;
• h2 is the heritability of IQ;
• m and f are the IQs of the mother and father, respectively. [17]
Thus, if the heritability of IQ is 50%, a couple averaging an IQ of 120 may have children that average around an IQ of 110, assuming that both parents come from a population with a median IQ of 100.
A caveat to this reasoning are those children who have chromosomal abnormalities, such as Klinefelter's syndrome and Triple X syndrome whose "normal" IQ is only one indicator; their visual IQ is another indicator. And so forth.
[edit] IQ and the brain
Main article: Neuroscience and intelligence
[edit] Brain size and IQ
Modern studies using MRI imaging have shown that brain size correlates with IQ (r = 0.35) among adults (McDaniel, 2005). The correlation between brain size and IQ seems to hold for comparisons between and within families (Gignac et al. 2003; Jensen 1994; Jensen & Johnson 1994). However, one study found no familial correlation (Schoenemann et al. 2000).
A study on twins (Thompson et al., 2001) showed that frontal gray matter volume was correlated with g and highly heritable. A related study has reported that the correlation between brain size (reported to have a heritability of 0.85) and g is 0.4, and that correlation is mediated entirely by genetic factors (Posthuma et al 2002).
In a study of the head growth of 633 term-born children from the Avon Longitudinal Study of Parents and Children cohort, it was shown that prenatal growth and growth during infancy were associated with subsequent IQ. The study’s conclusion was that the brain volume a child achieves by the age of 1 year helps determine later intelligence. Growth in brain volume after infancy may not compensate for poorer earlier growth. [18]
[edit] Brain areas associated with IQ
Many different sources of information have converged on the view that the frontal lobes are critical for fluid intelligence. Patients with damage to the frontal lobe are impaired on fluid intelligence tests (Duncan et al 1995). The volume of frontal grey (Thompson et al 2001) and white matter (Schoenemann et al 2005) have also been associated with general intelligence.
In addition, recent neuroimaging studies have limited this association to the lateral prefrontal cortex. Duncan and colleagues (2000) showed using Positron Emission Tomography that problem-solving tasks that correlated more highly with IQ also activate the lateral prefrontal cortex. More recently, Gray and colleagues (2003) used functional magnetic resonance imaging (fMRI) to show that those individuals that were more adept at resisting distraction on a demanding working memory task had both a higher IQ and increased prefrontal activity. For an extensive review of this topic, see Gray and Thompson (2004). [19]
In 2004, Richard Haier, professor of psychology in the Department of Pediatrics and colleagues at University of California, Irvine and the University of New Mexico used MRI to obtain structural images of the brain in 47 normal adults who also took standard IQ tests. The study demonstrated that general human intelligence appears to be based on the volume and location of gray matter tissue in the brain. Regional distribution of gray matter in humans is highly heritable. The study also demonstrated that, of the brain's gray matter, only about 6 percent appeared to be related to IQ. [20]
[edit] Brain structure and IQ
A study involving 307 children (age between six to nineteen) measuring the size of brain structures using magnetic resonance imaging (MRI) and measuring verbal and non-verbal abilities has been conducted (Shaw et al 2006). The study has indicated that there is a relationship between IQ and the structure of the cortex—the characteristic change being the group with the superior IQ scores starts with thinner cortex in the early age then becomes thicker than average by the late teens. [21]
[edit] The Flynn effect
Main article: Flynn effect
The Flynn effect is named after James R. Flynn, a New Zealand based political scientist. He discovered that IQ scores worldwide appear to be slowly rising at a rate of around three IQ points per decade (Flynn, 1999). Attempted explanations have included improved nutrition, a trend towards smaller families, better education, greater environmental complexity, and heterosis (Mingroni, 2004). However, tests are renormalized occasionally to obtain mean scores of 100, for example WISC-R (1974), WISC-III (1991) and WISC-IV (2003). Hence it is difficult to compare IQ scores measured years apart.
There is recent evidence that the tendency for intelligence scores to rise has ended in some first world countries. In 2004, Jon Martin Sundet of the University of Oslo and colleagues published an article documenting scores on intelligence tests given to Norwegian conscripts between the 1950s and 2002, showing that the increase in scores of general intelligence stopped after the mid-1990s and in numerical reasoning subtests, declined. [22]
Thomas W. Teasdale of the University of Copenhagen and David R. Owen of Brooklyn College, City University of New York, discovered similar results in Denmark, where intelligence test results showed no rise across the 1990s. [23]
Indications that scores on intelligence tests are not universally climbing have also come from the United Kingdom. Michael Shayer, a psychologist at King's College, University of London, and two colleagues report that performance on tests of physical reasoning given to children entering British secondary schools declined markedly between 1976 and 2003. [24]
[edit] Group differences
Among the most controversial issues related to the study of intelligence is the observation that intelligence measures such as IQ scores vary between populations. While there is little scholarly debate about the existence of some of these differences, the reasons remain highly controversial both within academia and in the public sphere.
[edit] Sex and intelligence
Main article: Sex and intelligence
Most studies show that despite sometimes significant differences in subtest scores, men and women have the same average IQ. Women perform better on tests of memory and verbal proficiency for example, while men perform better on tests of mathematical and spatial ability. Although gender-related differences in average IQ are insignificant, male scores display a higher variance: there are more men than women with both very high and very low IQs (for more details, see main article Sex and intelligence).
[edit] Race and IQ
Main article: Race and intelligence
While IQ scores of individual members of different racial or ethnic groups are distributed across the IQ scale, groups may vary in where their members cluster along the IQ scale. East Asians cluster higher than Europeans, while Hispanics and Sub-Saharan Africans cluster lower in the USA.[25] Much research has been devoted to the extent and potential causes of racial-ethnic group differences in IQ, and the underlying purposes and validity of the tests has been examined. Most experts conclude that examination of many types of test bias and simple differences in socioeconomic status have failed to explain the IQ clustering differences. [26] For a summary of expert opinions, see Race and Intelligence.
The findings in this field are often thought to conflict with fundamental social philosophies, and have resulted in controversy.[27]
[edit] Health and IQ
Persons with a higher IQ have generally lower adult morbidity and mortality. This may be because they better avoid injury and take better care of their own health, or alternatively may be due to a slight increased propensity for material wealth (see above). Post-Traumatic Stress Disorder, severe depression, and schizophrenia are less prevalent in higher IQ bands.
The Archive of General Psychiatry published a longitudinal study of a randomly selected sample of 713 study participants (336 boys and 377 girls), from both urban and suburban settings. Of that group, nearly 76 percent had suffered through at least one traumatic event. Those participants were assessed at age 6 years and followed up to age 17 years.
In that group of children, those with an IQ above 115 were significantly less likely to have Post-Traumatic Stress Disorder as a result of the trauma, less likely to display behavioral problems, and less likely to experience a trauma. The low incidence of Post-Traumatic Stress Disorder among children with higher IQs was true even if the child grew up in an urban environment (where trauma averaged three times the rate of the suburb), or had behavioral problems. [28] On the other hand, higher IQ shows a higher prevalence of those conditioned with Obsessive Compulsive Disorder. [29]
Research in Scotland has shown that a 15-point lower IQ meant people had a fifth less chance of seeing their 76th birthday, while those with a 30-point disadvantage were 37% less likely than those with a higher IQ to live that long. [30]
A decrease in IQ has also been shown as an early predictor of late-onset Alzheimer's Disease and other forms of dementia. In a 2004 study, Cervilla and colleagues showed that tests of cognitive ability provide useful predictive information up to a decade before the onset of dementia.[31]
However, when diagnosing individuals with a higher level of cognitive ability, in this study those with IQ's of 120 or more, [32] patients should not be diagnosed from the standard norm but from an adjusted high-IQ norm that measured changes against the individual's higher ability level.
In 2000, Whalley and colleagues published a paper in the journal Neurology, which examined links between childhood mental ability and late-onset dementia. The study showed that mental ability scores were significantly lower in children who eventually developed late-onset dementia when compared with other children tested. [33]
The longstanding belief that breast feeding correlates with an increase in the IQ of offspring has been challenged in a 2006 paper published in the British Medical Journal. The study used data from 5,475 children, the offspring of 3,161 mothers, in a longitudinal survey.
The results indicated that mother's IQ, not breast feeding, explained the differences in the IQ scores of offspring. The results of this study indicated that prior studies had not allowed for the mother's IQ. Since mother's IQ was predictive of whether a child was breast fed, the study concluded that "breast feeding [itself] has little or no effect on intelligence in children." Instead, it was the mother's IQ that had a significant correlation with the IQ of her offspring, whether the offspring was breast fed or was not breast fed. [34]
[edit] Wealth and IQ
A book IQ and the Wealth of Nations, claims to show that the wealth of a nation can in large part be explained by the average IQ score. This claim has been both disputed and supported in peer-reviewed papers. The data used has also been questioned.
In addition, IQ and its correlates to health, violent crime, gross state product, and government effectiveness are the subject of a 2006 paper in the publication Intelligence. The paper breaks down IQ averages by U.S. states using the federal government's National Assessment of Educational Progress math and reading test scores as a source. [35]
[edit] Practical validity
Linear correlations between 1000 pairs of numbers. The data are graphed on the lower left and their correlation coefficients listed on the upper right. Each set of points correlates maximally with itself, as shown on the diagonal (all correlations = +1).
Evidence for the practical validity of IQ comes from examining the correlation between IQ scores and life outcomes.
Economic and social correlates of IQ
Factors Correlation
School grades and IQ 0.5
Total years of education and IQ 0.55
IQ and parental socioeconomic status 0.33
Job performance and IQ 0.54
Negative social outcomes and IQ −0.2
IQs of identical twins 0.86
IQs of husband and wife 0.4
Heights of parent and child 0.47
Economic and social correlates of IQ in the USA
IQ <75 75–90 90–110 110–125 >125
U.S. population distribution 5 20 50 20 5
Married by age 30 72 81 81 72 67
Out of labor force more than 1 month out of year (men) 22 19 15 14 10
Unemployed more than 1 month out of year (men) 12 10 7 7 2
Divorced in 5 years 21 22 23 15 9
% of children w/ IQ in bottom decile (mothers) 39 17 6 7 < 1
Had an illegitimate baby (mothers)
32 17 8 4 2
Lives in poverty 30 16 6 3 2
Ever incarcerated (men) 7 7 3 1 < 1
Chronic welfare recipient (mothers) 31 17 8 2 < 1
High school dropout 55 35 6 0.4 < 0.4
Values are the percentage of each IQ sub-population, among non-Hispanic whites only, fitting each descriptor. Compiled by Gottfredson (1997) from a U.S. study by Herrnstein & Murray (1994) pp. 171, 158, 163, 174, 230, 180, 132, 194, 247–248, 194, 146 respectively.
Research shows that general intelligence plays an important role in many valued life outcomes. In addition to academic success, IQ correlates with job performance (see below), socioeconomic advancement (e.g., level of education, occupation, and income), and "social pathology" (e.g., adult criminality, poverty, unemployment, dependence on welfare, children outside of marriage). Recent work has demonstrated links between general intelligence and health, longevity, and functional literacy. Correlations between g and life outcomes are pervasive, though IQ and happiness do not correlate. IQ and g correlate highly with school performance and job performance, less so with occupational prestige, moderately with income, and to a small degree with law-abidingness.
General intelligence (in the literature typically called "cognitive ability") is the best predictor of job performance by the standard measure, validity. Validity is the correlation between score (in this case cognitive ability, as measured, typically, by a paper-and-pencil test) and outcome (in this case job performance, as measured by a range of factors including supervisor ratings, promotions, training success, and tenure), and ranges between −1.0 (the score is perfectly wrong in predicting outcome) and 1.0 (the score perfectly predicts the outcome). See validity (psychometric). The validity of cognitive ability for job performance tends to increase with job complexity and varies across different studies, ranging from 0.2 for unskilled jobs to 0.8 for the most complex jobs.
A meta-analysis (Hunter and Hunter, 1984) which pooled validity results across many studies encompassing thousands of workers (32,124 for cognitive ability), reports that the validity of cognitive ability for entry-level jobs is 0.54, larger than any other measure including job tryout (0.44), experience (0.18), interview (0.14), age (−0.01), education (0.10), and biographical inventory (0.37).
Because higher test validity allows more accurate prediction of job performance, companies have a strong incentive to use cognitive ability tests to select and promote employees. IQ thus has high practical validity in economic terms.
The utility of using one measure over another is proportional to the difference in their validities, all else equal. This is one economic reason why companies use job interviews (validity 0.14) rather than randomly selecting employees (validity 0.0).
However, legal barriers, most prominently the U.S. Civil Rights Act, as interpreted in the 1971 United States Supreme Court decision Griggs v. Duke Power Co., have prevented American employers from using cognitive ability tests as a controlling factor in selecting employees where (1) the use of the test would have a disparate impact on hiring by race and (2) where the test is not shown to be directly relevant to the job or class of jobs at issue.
Instead, where there is not direct relevance to the job or class of jobs at issue, tests have only been legally permitted to be used in conjunction with a subjective appraisal process. The U.S. military uses the Armed Forces Qualifying Test (AFQT), as higher scores correlate with significant increases in effectiveness of both individual soldiers and units, [36] and Microsoft is known for using non-illegal tests that correlate with IQ tests as part of the interview process, weighing the results even more than experience in many cases. [37]
Some researchers have echoed the popular claim that "in economic terms it appears that the IQ score measures something with decreasing marginal value. It is important to have enough of it, but having lots and lots does not buy you that much." [38] [39]
However, some studies suggest IQ continues to confer significant benefits even at very high levels. [40] Ability and performance for jobs are linearly related, such that at all IQ levels, an increase in IQ translates into a concomitant increase in performance (Coward and Sackett, 1990). In an analysis of hundreds of siblings, it was found that IQ has a substantial effect on income independently of family background (Murray, 1998).
Other studies question the real-world importance of whatever is measured with IQ tests, especially for differences in accumulated wealth and general economic inequality in a nation. IQ correlates highly with school performance but the correlations decrease the closer one gets to real-world outcomes, like with job performance, and still lower with income. It explains less than one sixth of the income variance. [41] Even for school grades, other factors explain most the variance. One study found that, controlling for IQ across the entire population, 90 to 95 percent of economic inequality would continue to exist. [42]
Another recent study (2002) 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. [43] Some argue that IQ scores are used as an excuse for not trying to reduce poverty or otherwise improve living standards for all. Claimed low intelligence has historically been used to justify the feudal system and unequal treatment of women (but note that many studies find identical average IQs among men and women; see sex and intelligence). In contrast, others claim that the refusal of "high-IQ elites" to take IQ seriously as a cause of inequality is itself immoral. [44]
[edit] Public policy
Main article: Intelligence and public policy
Because public policy is often intended to influence the same outcomes (for example to improve education, fight poverty and crime, promote fairness in employment, and counter racial discrimination), policy decisions frequently interact with intelligence measures. In some cases, modern public policy references intelligence measures or even aims to alter cognitive development directly.
While broad consensus exists that intelligence measures neither dictate nor preclude any particular social policy, controversy surrounds many other aspects of this interaction. Central issues concern whether intelligence measures should be considered in policy decisions, the role of policy in influencing or accounting for group differences in measured intelligence, and the success of policies in light of individual and group intelligence differences. The importance and sensitivity of the policies at issue have produced an often-emotional ongoing debate spanning scholarly inquiry and the popular media from the national to the local level.
[edit] Use of IQ in the United States legal system
Title VII of the Civil Rights Act generally prohibits employment practices that are unfair or discriminatory. One provision of Title VII, codified at 42 USC 2000e-2(h), specifically provides that it is not an "unlawful employment practice for an employer to give and to act upon the results of any professionally developed ability test provided that such test, its administration or action upon the results is not designed, intended or used to discriminate because of race, color, religion, sex or national origin." This statute was interpreted by the Supreme Court in Griggs v. Duke Power Co., 401 US 424 (1971).
In Griggs, the Court ruled that the reliance solely on a general IQ test that was not found to be specifically relevant to the job at issue was a discriminatory practice where it had a "disparate impact" on hiring. The Court gave considerable weight in its ruling to an Equal Employment Opportunity Commission regulation interpreting Section 2002e-2(h)'s reference to a "professionally developed ability test" to mean "a test which fairly measures the knowledge or skills required by the particular job or class of jobs which the applicant seeks, or which fairly affords the employer a chance to measure the applicant's ability to perform a particular job or class of jobs." In other words, the use of any particular test would need to be shown to be relevant to the particular job or class of jobs at issue.
In the educational context, the 9th Circuit Court of Appeals interpreted similar state and federal statutes to require that IQ Tests not be used in a manner that was determinative of tracking students into classes designed for the mentally retarded. Larry P. v. Riles, 793 F.2d 969 (9th Cir. 1984).
The court specifically found that the tests involved were designed and standardized based on an all-white population, and had not undergone a legislatively mandated validation process. In addition, the court ruled that predictive validity for a general population is not sufficient, since the rights of an individual student were at issue, and emphasized that had the tests not been treated as controlling but instead used as part of a thorough and individualized assessment by a school psychologist a different result would have been obtained.
In September 1982, the judge in the Larry P. case, Federal District Judge Robert F. Peckham, relented in part in response to a lawsuit brought by black parents who wanted their children tested. The parents' attorney, Mark Bredemeier, said his clients viewed the modern special education offered by California schools today as helpful to children with learning disabilities, not a dead-end track, as parents contended in the original 1979 Larry P. case.
The Supreme Court of the United States has utilized IQ test results during the sentencing phase of some criminal proceedings. The Supreme Court case of Atkins v. Virginia, decided June 20, 2002, [45] held that executions of mentally retarded criminals are "cruel and unusual punishments" prohibited by the Eighth Amendment. In Atkins the court stated that
"…[I]t appears that even among those States that regularly execute offenders and that have no prohibition with regard to the mentally retarded, only five have executed offenders possessing a known IQ less than 70 since we decided Penry. The practice, therefore, has become truly unusual, and it is fair to say that a national consensus has developed against it."
In overturning the Virginia Supreme Court's holding, the Atkins opinion stated that petitioner's IQ result of 59 was a factor making the imposition of capital punishment a violation of his eighth amendment rights. In the opinion's notes the court provided some of the facts relied upon when reaching their decision
At the sentencing phase, Dr. Nelson testified: "Atkins' full scale IQ is 59. Compared to the population at large, that means less than one percentile…. Mental retardation is a relatively rare thing. It's about one percent of the population." App. 274. According to Dr. Nelson, Atkins' IQ score "would automatically qualify for Social Security disability income." Id., at 280. Dr. Nelson also indicated that of the over 40 capital defendants that he had evaluated, Atkins was only the second individual who met the criteria for mental retardation. Id., at 310. He testified that, in his opinion, Atkins' limited intellect had been a consistent feature throughout his life, and that his IQ score of 59 is not an "aberration, malingered result, or invalid test score." Id., at 308.
.
The Social Security Administration also uses IQ results when deciding disability claims. In certain cases, IQ results alone are used (in those cases where the result shows a "full scale IQ of 59 or less") and in other cases IQ results are used along with other factors (for a "full scale IQ of 60 through 70") when deciding whether a claimant qualifies for Social Security Disability benefits.[46]
In addition, because people with IQs below 80 (the 10th percentile, Department of Defense "Category V") are difficult to train, federal law bars their induction into the military. As of 2005, only 4 percent of the recruits were allowed to score as low as in the 16th to 30th percentile, a grouping known as "Category IV" on the U.S. Armed Forces' mental-aptitude exam. [47]
[edit] Validity and g-loading of specific tests
While IQ is sometimes treated as an end unto itself, scholarly work on IQ focuses to a large extent on IQ's validity, that is, the degree to which IQ predicts outcomes such as job performance, social pathologies, or academic achievement. Different IQ tests differ in their validity for various outcomes.
Tests also differ in their g-loading, which is the degree to which the test score reflects general mental ability rather than a specific skill or "group factor" such as verbal ability, spatial visualization, or mathematical reasoning). g-loading and validity have been observed to be related in the sense that most IQ tests derive their validity mostly or entirely from the degree to which they measure g (Jensen 1998).
[edit] Controversy
[edit] Social construct
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Some maintain that IQ is a social construct invented by the privileged classes [citation needed], used to maintain their privilege.[citation needed] Others maintain that intelligence, measured by IQ or g, reflects a real ability, is a useful tool in performing life tasks and has a biological reality.
The social-construct and real-ability interpretations for IQ differences can be distinguished because they make opposite predictions about what would happen if people were given equal opportunities. The social explanation predicts that equal treatment will eliminate differences, while the real-ability explanation predicts that equal treatment will accentuate differences. Evidence for both outcomes exists. Achievement gaps persist in socioeconomically advantaged, integrated, liberal, suburban school districts in the United States (see Noguera, 2001). Test-score gaps tend to be larger at higher socioeconomic levels (Gottfredson, 2003). Some studies have reported a narrowing of score gaps over time.
The reduction of intelligence to a single score seems extreme and unrealistic to many people. Opponents argue that it is much more useful to know a person's strengths and weaknesses than to know a person's IQ score. Such opponents often cite the example of two people with the same overall IQ score but very different ability profiles.[citation needed] As measured by IQ tests, most people have highly balanced ability profiles, with differences in subscores being greater among the more intelligent.[citation needed] However, this assumes the ability of IQ tests to comprehensively gauge the wide variety of human intellectual abilities.
There are different types of IQ tests. Certainly the information described on this topic relates to a generic IQ test—against a general population, and therefore the results obtained are consistent across the population. However the results do not tell a full story, and are slanted towards 46,XX, and 46,XY candidates.[citation needed]
Candidates with Klinefelter's Syndrome, have a decreased frontal lobe, so for the most part have a reduced IQ when measured against the normal population (46,XX, and 46,XY candidates), but have an enhanced parietal lobe. If measured against IQ tests that are based on matching (patterns, shapes, colors, mathematical series, puzzles), some klinefelters measure into the genius level.[citation needed]
The creators of IQ testing did not intend for the tests to gauge a person's worth, and in many (or in all) situations, IQ may have little relevance. [citation needed]
[edit] The Mismeasure of Man
Some scientists dispute psychometrics entirely. In The Mismeasure of Man, a controversial book, professor Stephen Jay Gould argued that intelligence tests were based on faulty assumptions and showed their history of being used as the basis for scientific racism. He wrote:
…the abstraction of intelligence as a single entity, its location within the brain, its quantification as one number for each individual, and the use of these numbers to rank people in a single series of worthiness, invariably to find that oppressed and disadvantaged groups—races, classes, or sexes—are innately inferior and deserve their status. (pp. 24–25)
He spent much of the book criticizing the concept of IQ, including a historical discussion of how the IQ tests were created and a technical discussion of why g is simply a mathematical artifact. Later editions of the book included criticism of The Bell Curve, also a controversial book. Despite the many updates Gould made to his book, he did not discuss the modern usage of Magnetic Resonance Imaging (MRI) and other modern brain imaging techniques used in psychometrics.
Arthur Jensen, Professor of Educational Psychology, University of California, Berkeley, responded to Gould's criticisms in a paper titled The Debunking of Scientific Fossils and Straw Persons. [48]
[edit] The view of the American Psychological Association
In response to the controversy surrounding The Bell Curve, the American Psychological Association's Board of Scientific Affairs established a task force to write a consensus statement on the state of intelligence research which could be used by all sides as a basis for discussion. The full text of the report is available at a third-party website. [49]
The findings of the task force state that IQ scores do have high predictive validity for individual differences in school achievement. They confirm 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 (but specifically not population) differences in intelligence are substantially influenced by genetics.
They state there is little evidence to show that childhood diet influences intelligence except in cases of severe malnutrition. They agree that there are no significant differences between the average IQ scores of males and females. The task force agrees that large differences do exist between the average IQ scores of blacks and whites, and that these differences cannot be attributed to biases in test construction. While they admit there is no empirical evidence supporting it, the APA task force suggests that explanations based on social status and cultural differences may be possible. Regarding genetic causes, they noted that there is not much direct evidence on this point, but what little there is fails to support the genetic hypothesis.
The APA journal that published the statement, American Psychologist, subsequently published eleven critical responses in January 1997, most arguing that the report failed to examine adequately the evidence for partly-genetic explanations.
The report was published in 1995 and thus does not include a decade of recent research.
[edit] IQ test
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The controversy over IQ tests (also called cognitive ability tests [citation needed]), what they measure, and what this means for society has not abated since their initial development by Alfred Binet.
IQ tests rely largely upon Symbolic Logic [citation needed] as a means to scoring, and as Symbolic Logic is not inherently synonymous with intelligence [citation needed], the question remains as to exactly what is being measured via such tests. For instance, it is feasible that someone could possess a prodigious wealth of emotional intelligence while being simultaneously unable to comprehend the significance of sequentially arranged shapes [citation needed]. Additionally, someone who cannot read would be at a significant disadvantage on an IQ test [citation needed], though illiteracy is not indicative of being unintelligent. Measurements of other forms of "intelligence" have been proposed to augment the current IQ Testing Methodology, though such alternative measurements may also be a subject of debate.
Some key issues in the debate include defining intelligence itself (see general intelligence factor) and the political ramification of findings.
Some proponents of IQ testing argue that lower scores by certain groups justify cutting back on welfare and programs like Head Start and New Deal. Many proponents believe different IQ scores demonstrate that power and wealth will always be distributed unequally. Critics claim that IQ tests do not measure intelligence, but rather a specific skill set valued by those who create IQ tests.
Various statistical studies have reported that income level, education level, nutrition level, race, and sex all correlate with IQ scores, but what this means is debated.
Some researchers have concluded from twin studies and adoption studies that IQ has high heritability, and this is often interpreted by the general public as meaning that there is an immutable genetic factor affecting or determining intelligence [citation needed]. This hereditarian interpretation fuels much of the controversy over books such as The Bell Curve, which claimed that various racial groups have lower or higher group intelligence than other racial and ethnic groups (East Asians and Ashkenazi Jews, according to The Bell Curve, are slightly more intelligent on the average than generic whites, whereas blacks on the average have slightly lower IQs) and suggested changing public policy as a result of these findings.
The degree to which nature versus nurture influences the development of human traits (especially intelligence) is one of the most intractable scholarly controversies of modern times.
[edit] Notes
Linda S. Gottfredson (November 1998). The General Intelligence Factor. Scientific American. Retrieved on August 6, 2006.
Cervilla et al (2004). Premorbid cognitive testing predicts the onset of dementia and Alzheimer's disease better than and independently of APOE genotype. Psychiatry 2004;75:1100-1106.. Retrieved on August 6, 2006.
^ Whalley and Deary (2001). Longitudinal cohort study of childhood IQ and survival up to age 76. British Medical Journal 2001, 322:819-819. Retrieved on August 6, 2006.
^ Cervilla et al (2004). Premorbid cognitive testing predicts the onset of dementia and Alzheimer's disease better than and independently of APOE genotype. Psychiatry 2004;75:1100-1106.. Retrieved on August 6, 2006.
^ Whalley and Deary (2001). Longitudinal cohort study of childhood IQ and survival up to age 76. British Medical Journal 2001, 322:819-819. Retrieved on August 6, 2006.
^ Jensen, A.R. (1979)
^ R. Plomin, N. L. Pedersen, P. Lichtenstein and G. E. McClearn (Volume 24, Number 3 / May, 1994). Variability and stability in cognitive abilities are largely genetic later in life. Behavior Genetics. Retrieved on August 6, 2006.
^ Neisser et al. (August 7, 1995). Intelligence: Knowns and Unknowns. Board of Scientific Affairs of the American Psychological Association. Retrieved on August 6, 2006.
^ Thomas J. Bouchard Jr.; David T. Lykken; Matthew McGue; Nancy L. Segal; Auke Tellegen (October 12, 1990). Minnesota Study of Twins Reared Apart. National Institutes of Health / Science, Oct 12, 1990 v250 n4978 p223(6). Retrieved on August 6, 2006.
^ David L. Kirp (July 23, 2006). After the Bell Curve. New York Times Magazine. Retrieved on August 6, 2006.
^ Plomin et al. (2001, 2003)
^ Plomin et al. (2001, 2003)
^ Shannon, RWJ (2003, 2004, 2005)
^ June 24, 2002 (Steve Sailer). IQ Defenders Feel Vindicated by Supreme Court. UPI. Retrieved on August 6, 2006.
^ Coleen A. Boyle, et.al. (April 19, 1996). Prevalence of Selected Developmental Disabilities in Children 3-10 Years of Age: the Metropolitan Atlanta Developmental Disabilities Surveillance Program, 1991. National Center for Environmental Health, Division of Birth Defects and Developmental Disabilities. Retrieved on August 6, 2006.
^ June 24, 2002 (Steve Sailer). IQ Defenders Feel Vindicated by Supreme Court. UPI. Retrieved on August 6, 2006.
^ Phillip McClean (1997,1999). Estimating the Offspring Phenotype. Quantitative Genetics. Retrieved on August 6, 2006.
^ Catharine R. Gale, PhD, Finbar J. O'Callaghan, PhD, Maria Bredow, MBChB, Christopher N. Martyn, DPhil and the Avon Longitudinal Study of Parents and Children Study Team (October 4, 2006). The Influence of Head Growth in Fetal Life, Infancy, and Childhood on Intelligence at the Ages of 4 and 8 Years. PEDIATRICS Vol. 118 No. 4 October 2006, pp. 1486-1492. Retrieved on August 6, 2006.
^ Jeremy R. Gray, Psychology Department, Yale University, and Paul M. Thompson, Laboratory of Nero Imaging, Department of Neurology, University of California, Los Angeles School of Medicine (June 2004). Neurobiology of Intelligence: Science and Ethics. Nature Publishing Group, Volume 5. Retrieved on August 6, 2006.
^ Richard Haier (July 19, 2004). Human Intelligence Determined by Volume and Location of Gray Matter Tissue in Brain. Brain Research Institute, UC Irvine College of Medicine. Retrieved on August 6, 2006.
^ Nicholas Wade (March 30, 2006). Scans Show Different Growth for Intelligent Brains. Brain Research Institute, UCLA. Retrieved on August 6, 2006.
^ The end of the Flynn Effect. A study of secular trends in mean intelligence scores of Norwegian conscripts during half a century.. Retrieved on August 6, 2006.
^ A long-term rise and recent decline in intelligence test performance: The Flynn Effect in reverse.. Retrieved on August 6, 2006.
^ Children are less able than they used to be. Retrieved on August 6, 2006.
^ Gottfredson et al. 1994 (ctrl+f "groups")
^ Neisser et al. (August 7, 1995). Intelligence: Knowns and Unknowns. Board of Scientific Affairs of the American Psychological Association. Retrieved on August 6, 2006.
^ The controversy itself has caused some scientists to debate whether such fields of inquiry are not scientific, or whether group differences in traits are just another area of the science of human nature, as Steven Pinker and others argue. (See Race and intelligence#Utility of research and racism.)
^ Naomi Breslau, PhD; Victoria C. Lucia, PhD; German F. Alvarado, MD, MPH (11, November 2006). Intelligence and Other Predisposing Factors in Exposure to Trauma and Posttraumatic Stress Disorder. A Follow-up Study at Age 17 Years. Arch Gen Psychiatry. 2006;63:1238-1245. Retrieved on August 6, 2006.
^ GT_DM_5b.pdf (PDF).
^ Whalley and Deary (2001). Longitudinal cohort study of childhood IQ and survival up to age 76. British Medical Journal 2001, 322:819-819. Retrieved on August 6, 2006.
^ Cervilla et al (2004). Premorbid cognitive testing predicts the onset of dementia and Alzheimer's disease better than and independently of APOE genotype. Psychiatry 2004;75:1100-1106.. Retrieved on August 6, 2006.
^ Dorene Rentz, Brigham and Women's Hospital's Department of Neurology and Harvard Medical School. More Sensitive Test Norms Better Predict Who Might Develop Alzheimer's Disease. Neuropsychology, published by the American Psychological Association. Retrieved on August 6, 2006.
\^ Whalley et al. (2000). Childhood mental ability and dementia. Neurology 2000;55:1455-1459.. Retrieved on August 6, 2006.
^ Geoff Der, G David Batty, Ian J. Deary (2006). Effect of breast feeding on intelligence in children: prospective study, sibling pairs analysis, and meta-analysis (Abstract). British Medical Journal.
^ Michael A. McDaniel, Virginia Commonwealth University (accepted for publication August 2006). Estimating state IQ: Measurement challenges and preliminary correlates (PDF). Intelligence.
^ RAND_TR193.pdf (PDF)., MR818.ch2.pdf (PDF).
^ Rich Karlgaard (October 31, 2005). Talent Wars. Forbes. Retrieved on August 6, 2006.
^ Detterman and Daniel, 1989.
^ Earl Hunt. The Role of Intelligence in Modern Society pp. 4 (Nonlinearities in Intelligence). American Scientist. Retrieved on August 6, 2006.
^ Top1in10000.pdf (PDF). Retrieved on August 6, 2006.
^ Neisser et al. (August 7, 1995). Intelligence: Knowns and Unknowns. Board of Scientific Affairs of the American Psychological Association. Retrieved on August 6, 2006.
^ IQ best predicts if you will succeed or fail in life. Retrieved on August 6, 2006.
^ intergen.pdf (PDF). Retrieved on August 6, 2006.
^ Steve Sailer. How to Help the Left Half of the Bell Curve. VDARE.com. Retrieved on August 6, 2006.
^ DARYL RENARD ATKINS, PETITIONER v. VIRGINIA (June 20, 2002). Retrieved on August 6, 2006.
^ SOCIAL SECURITY ADMINISTRATION.
^ DoD (September 20, 2005). Department of Defense INSTRUCTION, Number 1145.01. Retrieved on August 6, 2006.
^ Jensen, Arthur (1982). "The Debunking of Scientific Fossils and Straw Persons". Contemporary Education Review 1 (2): 121-135. Retrieved on 2006-08-06.
^ Neisser et al. (August 7, 19). Intelligence: Knowns and Unknowns. Board of Scientific Affairs of the American Psychological Association. Retrieved on August 6, 2006.
[edit] See also
• High IQ Societies
• Nature versus nurture
• Emotional intelligence
• Theory of multiple intelligences
• Gifted
• SAT
• Graduate Record Examination
[edit] References
• Carroll, J.B. (1993). Human cognitive abilities: A survey of factor-analytical studies. New York: Cambridge University Press.
• Coward, W.M. and Sackett, P.R. (1990). Linearity of ability-performance relationships: A reconfirmation. Journal of Applied Psychology, 75:297–300.
• Duncan, J., P. Burgess, and H. Emslie (1995) Fluid intelligence after frontal lobe lesions. Neuropsychologia, 33(3): p. 261-8.
• Duncan, J., et al., A neural basis for general intelligence. Science, 2000. 289(5478): p. 457-60.
• Flynn, J.R. (1999). Searching for Justice: The discovery of IQ gains over time. American Psychologist, v. 54, p. 5-20
• Frey, M.C. and Detterman, D.K. (2003) Scholastic Assessment or g? The Relationship Between the Scholastic Assessment Test and General Cognitive Ability. Psychological Science, 15(6):373–378. PDF
• Gottfredson, L. S. (1997). "Why g matters: The complexity of everyday life." Intelligence, 24(1), 79–132. PDF
• Gottfredson, L.S. (1998). The general intelligence factor. Scientific American Presents, 9(4):24–29. PDF
• Gottfredson, L. S. (2005). Suppressing intelligence research: Hurting those we intend to help. In R. H. Wright & N. A. Cummings (Eds.), Destructive trends in mental health: The well-intentioned path to harm (pp. 155–186). New York: Taylor and Francis. Pre-print PDF PDF
• Gottfredson, L. S. (in press). "Social consequences of group differences in cognitive ability (Consequencias sociais das diferencas de grupo em habilidade cognitiva)". In C. E. Flores-Mendoza & R. Colom (Eds.), Introdução à psicologia das diferenças individuais. Porto Alegre, Brazil: ArtMed Publishers. PDF
• Gray, J.R., C.F. Chabris, and T.S. Braver, Neural mechanisms of general fluid intelligence. Nat Neurosci, 2003. 6(3): p. 316-22.
• Gray, J.R. and P.M. Thompson, Neurobiology of intelligence: science and ethics. Nat Rev Neurosci, 2004. 5(6): p. 471-82.
• Haier RJ, Jung RE, Yeo RA, et al. (2005). "The neuroanatomy of general intelligence: sex matters". NeuroImage 25: 320–327.
• Harris, J. R. (1998). The nurture assumption : why children turn out the way they do. New York, Free Press.
• Hunt, E. (2001). Multiple views of multiple intelligence. [Review of Intelligence Reframed: Multiple Intelligences for the 21st Century.]
• Jensen, A.R. (1979). Bias in mental testing. New York: Free Press.
• Jensen, A.R. (1998). The g Factor. Praeger, Connecticut, USA.
• Jensen, A.R. (2006). "Clocking the Mind: Mental Chronometry and Individual Differences." Elsevier Science. --->New release scheduled for early June, 2006.
• Klingberg, T., Forssberg, H., & Westerberg, H. (2002). Training of working memory in children with ADHD. Journal of Clinical & Experimental Neuropsychology, 24, 781-791.
• McClearn, G. E., Johansson, B., Berg, S., Pedersen, N. L., Ahern, F., Petrill, S. A., & Plomin, R. (1997). Substantial genetic influence on cognitive abilities in twins 80 or more years old. Science, 276, 1560–1563.
• McDaniel, M.A. (2005) Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence. Intelligence, 33, 337-346.
• Mingroni, M.A. (2004). "The secular rise in IQ: Giving heterosis a closer look". Intelligence 32: 65–83.
• Murray, Charles (1998). Income Inequality and IQ, AEI Press PDF
• Noguera, P.A. (2001). Racial politics and the elusive quest for excellence and equity in education. In Motion Magazine article
• Plomin, R., DeFries, J. C., Craig, I. W., & McGuffin, P. (2003). Behavioral genetics in the postgenomic era. Washington, DC: American Psychological Association.
• Plomin, R., DeFries, J. C., McClearn, G. E., & McGuffin, P. (2001). Behavioral genetics (4th ed.). New York: Worth Publishers.
• Rowe, D. C., W. J. Vesterdal, and J. L. Rodgers, "The Bell Curve Revisited: How Genes and Shared Environment Mediate IQ-SES Associations," University of Arizona, 1997
• Schoenemann, P.T., M.J. Sheehan, and L.D. Glotzer, Prefrontal white matter volume is disproportionately larger in humans than in other primates. Nat Neurosci, 2005.
• Shaw P, Greenstein D, Lerch J, Clasen L, Lenroot R, Gogtay N, Evans A, Rapoport J, and Giedd J (2006), "Intellectual ability and cortical development in children and adolescents". Nature 440, 676-679.
• Tambs K, Sundet JM, Magnus P, Berg K. "Genetic and environmental contributions to the covariance between occupational status, educational attainment, and IQ: a study of twins." Behav Genet. 1989 Mar;19(2):209–22. PMID 2719624.
• Thompson, P.M., Cannon, T.D., Narr, K.L., Van Erp, T., Poutanen, V.-P., Huttunen, M., Lönnqvist, J., Standertskjöld-Nordenstam, C.-G., Kaprio, J., Khaledy, M., Dail, R., Zoumalan, C.I., Toga, A.W. (2001). "Genetic influences on brain structure." Nature Neuroscience 4, 1253-1258.
[edit] External links
[edit] Collective statements
• The Wall Street Journal: Mainstream Science on Intelligence
• PDF Reprint - Mainstream science on intelligence: An editorial with 52 signatories, history, and bibliography.
• APA: Intelligence: Knowns and Unknowns
• APA Committee on Online Psychological Tests and Assessment report
[edit] Review papers
• Scientific American: The General Intelligence Factor
• Scientific American: Intelligence Considered
• Neurobiology of Intelligence: Science and Ethics PDF
[edit] Professional Intelligence Testing
• "Scans Show Different Growth for Intelligent Brains", New York Times, March 30, 2006
Retrieved from "http://en.wikipedia.org/wiki/Intelligence_quotient"
Categories: Articles with unsourced stateme
Low IQs are Africa's curse, says lecturer
Researcher accused of promoting racist stereotype wins backing from LSE
Denis Campbell
Sunday November 5, 2006
The Observer
The London School of Economics is embroiled in a row over academic freedom after one of its lecturers published a paper alleging that African states were poor and suffered chronic ill-health because their populations were less intelligent than people in richer countries.
Satoshi Kanazawa, an evolutionary psychologist, is now accused of reviving the politics of eugenics by publishing the research which concludes that low IQ levels, rather than poverty and disease, are the reason why life expectancy is low and infant mortality high. His paper, published in the British Journal of Health Psychology, compares IQ scores with indicators of ill health in 126 countries and claims that nations at the top of the ill health league also have the lowest intelligence ratings.
Paul Collins, a spokesman for War On Want, the international development charity, said the research 'runs the risk of resurrecting the racist stereotype that Africans are responsible for their own plight, and may reinforce prejudices that Africans are less intelligent'.
Collins added: 'The notion that people in poor countries have inferior intelligence has been disproved by much research in the past. This is another example, which other academics will shoot down.'
Philippa Atkinson, who chairs the LSE student union's 85-strong Africa Forum and teaches in the school's Department of Government, said the paper 'reflects the now discredited theories of eugenics, which should have been left behind'.
'Eugenics was a very influential discourse for centuries,' she said. 'It's the discourse that colonialism and racism in America until the Sixties were based on, and was part of the basis of apartheid too. Nobody could prove that there are racial or national differences in IQ. It's very, very controversial to say that national IQ levels are low in Africa, and completely unproven. It's a surprise that the odd person would try to bring it back,' she said.
However, she said the research contained some interesting ideas and merited serious consideration, and stressed that academics such as Kanazawa should not be deterred from exploring controversial subjects.
The reaction to Kanazawa's paper will reopen the simmering debate about whether academics are entitled to express opinions that many people may find offensive.
The Observer revealed last March that Frank Ellis, a lecturer in Russian and Slavonic studies at Leeds University, supported the Bell Curve theory, which holds that black people are less intelligent than whites. He also believed that women did not have the same intellectual capacity as men and backed the 'humane' repatriation of ethnic minorities. Initially, the university backed Ellis, despite protests by students and teaching staff, but he took early retirement in July.
Kanazawa declined to comment on either War on Want or Atkinson's allegations about reviving eugenics because, he said, other academics had come up with the national IQ scores that underpinned his analysis of 126 countries. In the paper he cites Ethiopia's national IQ of 63, the world's lowest, and the fact that men and women are only expected to live until their mid-40s as an example of his finding that intelligence is the main determinant of someone's health.
Having examined the effects of economic development and income inequality on health, he was 'surprised' to find that IQ had a much more important impact, he said. 'Poverty, lack of sanitation, clean water, education and healthcare do not increase health and longevity, and nor does economic development.'
The LSE declined to offer any opinion on Kanazawa's conclusions but defended his right to publish controversial research. A spokeswoman said: 'This is academic research by Dr Kanazawa based on empirical data and published in a peer-reviewed journal. People may agree or disagree with his findings and are at liberty to voice their opinions to him. The school does not take any institutional view on the work of individual academics.'
Kate Raworth, a senior researcher with Oxfam, said it was 'ridiculous' for Kanazawa to blame ill health on low IQ and 'very irresponsible' to reach such conclusions using questionable and 'fragile' international data on national IQ levels.
Rumit Shah, chairman of the LSE student union's 52-member Kenyan Society, said lack of education was probably one reason why many Kenyans die young. Aids, tuberculosis and malaria were key factors too.
Kanazawa's article was a 'misrepresentation' of the true causes of ill health in Kenya, added Shah. 'It portrays a bad picture of Kenya, because not everyone in Kenya has an IQ of 72. If there was more education, Kenyans would be wiser about their health.'
Belai Habte-Jesus, MD, MPH
Global Strategic Enterprises, Inc;e-mail:globalbelai@yahoo.com; Telephone: 703 933 8737
CONFIDENTIALITY NOTICE: This electronic message, including any attachment(s), is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. .
Dorina Asmanio
Low IQs are Africa's curse, says lecturer
Researcher accused of promoting racist stereotype wins backing from LSE
Denis Campbell
Sunday November 5, 2006
The Observer
Photo Credit The London School of Economics (LSE)
The London School of Economics is embroiled in a row over academic freedom after one of its lecturers published a paper alleging that African states were poor and suffered chronic ill-health because their populations were less intelligent than people in richer countries.
Satoshi Kanazawa, an evolutionary psychologist, is now accused of reviving the politics of eugenics by publishing the research which concludes that low IQ levels, rather than poverty and disease, are the reason why life expectancy is low and infant mortality high. His paper, published in the British Journal of Health Psychology, compares IQ scores with indicators of ill health in 126 countries and claims that nations at the top of the ill health league also have the lowest intelligence ratings.
In the paper he cites Ethiopia's national IQ of 63
Paul Collins, a spokesman for War On Want, the international development charity, said the research 'runs the risk of resurrecting the racist stereotype that Africans are responsible for their own plight, and may reinforce prejudices that Africans are less intelligent'.
Collins added: 'The notion that people in poor countries have inferior intelligence has been disproved by much research in the past. This is another example, which other academics will shoot down.'
Philippa Atkinson, who chairs the LSE student union's 85-strong Africa Forum and teaches in the school's Department of Government, said the paper 'reflects the now discredited theories of eugenics, which should have been left behind'.
'Eugenics was a very influential discourse for centuries,' she said. 'It's the discourse that colonialism and racism in America until the Sixties were based on, and was part of the basis of apartheid too. Nobody could prove that there are racial or national differences in IQ. It's very, very controversial to say that national IQ levels are low in Africa , and completely unproven. It's a surprise that the odd person would try to bring it back,' she said.
However, she said the research contained some interesting ideas and merited serious consideration, and stressed that academics such as Kanazawa should not be deterred from exploring controversial subjects.
The reaction to Kanazawa 's paper will reopen the simmering debate about whether academics are entitled to express opinions that many people may find offensive.
The Observer revealed last March that Frank Ellis, a lecturer in Russian and Slavonic studies at Leeds University , supported the Bell Curve theory, which holds that black people are less intelligent than whites. He also believed that women did not have the same intellectual capacity as men and backed the 'humane' repatriation of ethnic minorities. Initially, the university backed Ellis, despite protests by students and teaching staff, but he took early retirement in July.
Kanazawa declined to comment on either War on Want or Atkinson's allegations about reviving eugenics because, he said, other academics had come up with the national IQ scores that underpinned his analysis of 126 countries. In the paper he cites Ethiopia 's national IQ of 63, the world's lowest, and the fact that men and women are only expected to live until their mid-40s as an example of his finding that intelligence is the main determinant of someone's health.
Having examined the effects of economic development and income inequality on health, he was 'surprised' to find that IQ had a much more important impact, he said. 'Poverty, lack of sanitation, clean water, education and healthcare do not increase health and longevity, and nor does economic development.'
The LSE declined to offer any opinion on Kanazawa 's conclusions but defended his right to publish controversial research. A spokeswoman said: 'This is academic research by Dr Kanazawa based on empirical data and published in a peer-reviewed journal. People may agree or disagree with his findings and are at liberty to voice their opinions to him. The school does not take any institutional view on the work of individual academics.'
Kate Raworth, a senior researcher with Oxfam, said it was 'ridiculous' for Kanazawa to blame ill health on low IQ and 'very irresponsible' to reach such conclusions using questionable and 'fragile' international data on national IQ levels.
Rumit Shah, chairman of the LSE student union's 52-member Kenyan Society, said lack of education was probably one reason why many Kenyans die young. Aids, tuberculosis and malaria were key factors too.
Kanazawa 's article was a 'misrepresentation' of the true causes of ill health in Kenya , added Shah. 'It portrays a bad picture of Kenya , because not everyone in Kenya has an IQ of 72. If there was more education, Kenyans would be wiser about their health.'
---------------
Contact info for Dr. Satoshi Kanazawa
s.kanazawa@lse.ac.uk
LSE phone number: 020 7955 7297
WebSite
---------------
Related Links
Average person in Ethiopia retarded? What?!
Mild mental retardation: IQ 50–55 to 70
Moderate retardation: IQ 35–40 to 50–55;
Severe mental retardation: IQ 20–25 to 35–40
Profound mental retardation: IQ below 20–25
Source: Wikipedia
-----------------------------
The British Journal of Health Psychology
Mind the gap…in intelligence: Re-examining the relationship between inequality and health
Author: Kanazawa , Satoshi1
Source: British Journal of Health Psychology, Volume 11, Number 4, November 2006, pp. 623-642(20)
Belai Habte-Jesus, MD, MPH
Global Strategic Enterprises, Inc; e-mail:globalbelai@yahoo.com; Telephone: 703 933 8737
CONFIDENTIALITY NOTICE: This electronic message, including any attachment(s), is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. .
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Dear All
in relation to the recent controversy of this guy from LSE. I'd like to proudly bring to your attention a forthcoming review of Dr. Girma Berhanu from Goteborg University for the controversial book "IQ and the Wealth of Nations" by Lynn and Vanhanen from which Kanazawa from LSE copied the alleged national IQ's. As recalled, Lynn and Vanhanen calculated 63 as the national IQ of Ethiopia (the lowest in the world) and it turns out that they did so on the basis of test results from Ethiopian-Jewish young students in Israel (a fact that was brought to my attention by Dr. Girma) which in itself is outrageous!
you can read the abstract for his review and also a letter he sent to the journal's editor.
I really thank Dr. Girma Berhanu for taking the initiative to challenge these racist views that unfortunately many find still to be appropriate to entertain in higher educational and academic institutions.
here is what i wrote on Kanazawa's article: http://www.ethrev.com/articles/Nov2006/DanielAlemu_11082006.html
Thanks,
Daniel Alemu,
London
Black Intellectual genocide: When does all this ‘?abstract atrocities’ end?
A Response to “IQ and the Wealth of Nations” by Richard Lynn & Tatu Vanhanen
Girma Berhanu Department of Education
Göteborg University
> > Box 300, SE 405 30
> > Göteborg, Sweden
> > Tel. +46 (0) 31-7732325
> > Fax +46 (0) 31-7732315
> > E-mail: Girma.Berhanu@ped.gu.se
Intelligent Quotient and the Wealth of Nations
Abstract
This paper is a response to the book ”IQ and the wealth of nations” written by Richard Lynn & Tatu Vanhanen. It is a critique of the authors’ major assertion that a significant part of the gap between rich and poor countries is due to differences in national intelligence. (The authors claim that they have evidence that differences in national IQ account for the substantial variation in national per capita income and growth).
This paper debunks their assumptions that intellectual and income differences between nations stems from genetic differences. This critique provides an extended review of the research literature that tells different stories (from what the authors postulate) about the concept of intelligence, what IQ measures and does not measure. The paper exposes the racist, sexist and antihuman nature of the research tradition in which the authors anchored their studies and the deep methodological flaw, and theoretical assumptions used in their book.
The low standards of scholarship evident in the book render it largely irrelevant for modern science. This paper has specifically dealt with the IQ value of Ethiopian immigrants that came from Israel, used by the authors as representing the National Average IQ of Ethiopia. Most of these immigrants hade rudimentary knowledge of literacy, and experienced abrupt transition from rural Ethiopia to Israel with all the accompanying effects that it entails such as trauma, dislocation and cultural shock. The test was conducted a few months after their arrival. That specific study (conducted by two Israelis) that assigns low IQ for the immigrants is also replete with technical/statistical errors to say the least. The paper concludes that this is tantamount to intellectual genocide deserving a legal treatment by the International Court of Justice.
Keywords: Scientific racism, Mental (IQ) testing, Intelligence, Economic development, Intellectual Genocide the request for the review of the book:
(1)The book I want to comment on is entitled”IQ and the wealth of
nations”. It is written by Richard Lynn (prof. emeritus of psychology at the
University of Ulster, North Ireland) and Tatu Vanhanen (prof. emeritus of
political science at the University of Tampere in Finland). I came to
notice the debate surrounding the book this past summer during my holiday
in Finland. The second author, Prof. Vanhanen, was interviewed by a Finnish
journalist (s) about the book and he expressed his view that IQ and the
wealth of nations are strongly correlated and the reason why some countries
are poor has to do with their IQ. He further indicated that IQ is
substantially heritable and racial differences in intelligence are not a myth
but a fact of life. His statement also carried the message that poor
countries should blame themselves for their poverty. His outrageous
statements were widely criticized by Finnish media and have been the subject
of hot debate during this past summer.
I presume the issue became interesting not really because the governing elite is genuinely concerned about the cultural / political message that he conveyed but because the man is the father of the current prime minister of Finland. And it was the opposition party that instigated the debate which in many ways embarrassed the prime minister. The prime minister commented “my father is a bit confused because of age”. This is just to tell you how I came to read the book.
The authors argue that a significant part of the gap between rich and poor
countries is due to differences in national intelligence. Their hypothesis
is that the intelligence of the populations has been a major factor responsible
for the national differences in economic growth and the gap in per capita
income between rich and poor nations The argument is line with Arthur R. Jensen’s controversial article in Harvard Educational Review (1969) through to Richard Herrnstein and
Charles Murray’s (1994) book, The Bell curve and J. Philippe Ruston’s book
Race, evolution and behavior (?). The difference is that these studies
attempt to document the relationship between IQ and individual achievement
and racial differences in intelligence where as Lynn and Vanhanen have
scaled this connection up to a national level. The authors ridicule
enrichment programmes and cognitive education aimed at raising school
performance among disadvantaged children.
To get to my point, the IQ figure which stood to represent Ethiopia came
from Israel, not directly from Ethiopia[1]. It is very likely that a few of
them (I mean ‘the people whose apparent IQ levels were used’) were my friends. Most of these students (250) who are described in Lynn’s and Vanhanen’s book as having IQs of 63 are presently having a satisfying life and are occupationally competent and socially adequate. (They
are in their late 20s or early 30s.) I am confident that some of them have
done their first (and second) degrees, if not in Israel in the USA. As many of
us know, these young immigrants were new arrivals, malnourished, unfamiliar
with “western school based skills”; they had lived as refugees in the Sudan under
hard poverty, while in Ethiopia they lived most of their life in isolation
from and suffering discrimination from the dominant Christian neighbors, and many lost their parents during the mysterious journey to Israel; they were “saved”
through a dramatic life-saving operation by Mossad. Most of these young people had rudimentary knowledge of formal education and the Hebrew language, and had followed a very traditional way of life while in Ethiopia, so the dramatic and abrupt transition from village life in Ethiopia to Israel which occurred en masse was accompanied by adjustment crises which in turn immensely affected their learning and integration in to Israeli society. The authors
tested these young people and concluded that the average Ethiopian IQ is 63.
What is outrageous about the book is its emphasis on one direction of
causation ie a high IQ is the cause of a high income and intellectual and
income differences between nations stems from genetic differences. “… we
believe that national differences in intelligence have a substantial
genetic basis…” (p.193 ) Do they have the data to substantiate this claim? None, except for a fragmented, undocumented and extremely over-simplified assertion about the effects of trans-racial adoption and a few twin studies. The distorted data allows them to talk only about the strength of relationships not cause and effect relationships.
With kindest regards!
Girma Berhanu
[1] (see Kaniel, Shlomo; Fisherman, Shraga.
Title Level of performance and distribution of errors in the Progressive Matrices test: A comparison of Ethiopian immigrant and native Israeli adolescents.
Source
International Journal of Psychology. Vol 26(1) 1991, 25-33
IQ and the Wealth of Nations
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IQ and the Wealth of Nations
IQ and the Wealth of Nations is a controversial 2002 book by Dr. Richard Lynn, Professor Emeritus of Psychology at the University of Ulster, Northern Ireland, and Dr. Tatu Vanhanen, Professor Emeritus of Political Science at the University of Tampere, Tampere, Finland. The book demonstrates that differences in national income (in the form of per capita gross domestic product) correlate with, and arguably attributes it to, differences in average national IQ.
The book was followed by Lynn's 2006 Race Differences in Intelligence, which expands the data by nearly four times and concludes the average human IQ is presently 90 when compared to a norm of 100 based on UK data, or two thirds of a standard deviation below the UK norm.
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[edit] Outline
The central thesis of IQ and the Wealth of Nations is that the average IQ of a nation correlates with its GDP. Above is a scatterplot with Lynn and Vanhanen's IQ figures and estimates² (explained below) plotted against 2004 per capita GDP (PPP), as reported by the IMF.³ Similar diagrams appear in the book.
The book includes the authors' estimates of average IQ scores for each country, based on their analysis of published reports; their observation that national gross domestic product per capita is correlated with IQ; and their conclusion that the IQ differences correlated with income differences by a factor of about 0.7, meaning that IQ explains more than half of the variation in per capita GDP.
The authors stated that they believe IQ is due to both genetic and environmental factors. They also stated that low GDP can cause low IQ, just as low IQ can cause low GDP. (See: Positive feedback)
The authors argued that it is the ethical responsibility of rich, high-IQ nations to financially assist poor, low-IQ nations, as it is the responsibility of rich citizens to assist the poor.
The book was cited several times in the popular press, notably the British conservative newspaper The Times. Because Tatu Vanhanen is the father of Matti Vanhanen, the Finnish Prime minister, his work has received wide publicity in Finland.
[edit] National IQ estimates
Central to the book's thesis is a tabulation of what Lynn and Vanhanen believe to be the average IQs of the world's nations. Rather than do their own IQ studies (a potentially massive project), the authors average and adjust existing studies.
For most of the 185 nations, no reliable studies are available. In those cases, the authors have used an estimated value by taking averages of the IQs of surrounding nations. For example, the authors arrived at a figure of 84 for El Salvador by averaging their calculations of 79 for Guatemala and 88 for Colombia. Those estimates are not included in the calculations of income differences and do not appear in the table below.
Several cases merit specific attention. To obtain a figure for South Africa, the authors averaged IQ studies done on different ethnic groups, resulting in a figure of 72. The figures for Colombia, Peru and Singapore were arrived at in a similar manner. For People's Republic of China, the authors used a figure of 109.4 for Shanghai and adjusted it down by an arbitrary 6 points because they believed the average across China's rural areas was probably less than that in Shanghai. Another figure from a study done in Beijing was not adjusted downwards. Those two studies formed the resultant score for China (PRC).
In many cases, the IQ of a country is estimated by averaging the IQs of "neighboring countries" that are not actually neighbors of the country in question. For example, Kyrgyzstan's IQ is estimated by averaging the IQs of Iran and Turkey, neither of which is close to Kyrgyzstan – China, which is a neighbor, is not counted as such by Lynn and Vanhanen. Such arbitrary selections of "neighbors" raise additional questions as to the objectivity of the IQ estimates.[citation needed]
To account for the Flynn effect (an increase in IQ scores over time), the authors sometimes adjusted the results of older studies upward by an arbitrary number of points. Because of these arbitrary adjustments and the fact that only limited data were available for most nations, the figures should be considered rough estimates.[citation needed]
Country IQ estimate Country IQ estimate Country IQ estimate
Hong Kong (PRC)
107 Russia
96 Fiji
84
South Korea
106 Slovakia
96 Iran
84
Japan
105 Uruguay
96 Marshall Islands
84
Taiwan (ROC)
104 Portugal
95 Puerto Rico (US)
84
Singapore
103 Slovenia
95 Egypt
83
Austria
102 Israel
94 India
81
Germany
102 Romania
94 Ecuador
80
Italy
102 Bulgaria
93 Guatemala
79
Netherlands
102 Ireland
93 Barbados
78
Sweden
101 Greece
92 Nepal
78
Switzerland
101 Malaysia
92 Qatar
78
Belgium
100 Thailand
91 Zambia
77
China (PRC)
100 Croatia
90 Congo-Brazzaville
73
New Zealand
100 Peru
90 Uganda
73
United Kingdom
100 Turkey
90 Jamaica
72
Hungary
99 Indonesia
89 Kenya
72
Poland
99 Suriname
89 South Africa
72
Australia
98 Colombia
89 Sudan
72
Denmark
98 Brazil
87 Tanzania
72
France
98 Iraq
87 Ghana
71
Norway
98 Mexico
87 Nigeria
67
United States
98 Samoa
87 Guinea
66
Canada
97 Tonga
87 Zimbabwe
66
Czech Republic
97 Lebanon
86 Congo-Kinshasa
65
Finland
97 Philippines
86 Sierra Leone
64
Spain
97 Cuba
85 Ethiopia
63
Argentina
96 Morocco
85 Equatorial Guinea
59
[edit] Special cases
In several cases, actual GDP did not correspond with that predicted by IQ. In these cases, the authors argued that differences in GDP were caused by differences in natural resources and whether the nation used a "planned" or "market" economy.
One example of this was Qatar, whose IQ was estimated by Lynn and Vanhanen to be about 78, yet had a disproportionately high per capita GDP of roughly USD $17,000. The authors explain Qatar's disproportionately high GDP by its high petroleum resources. Similarly, the authors think that large resources of diamonds explain the economic growth of the African nation Botswana, the fastest in the world for several decades.
The authors argued that the People's Republic of China's per capita GDP of roughly USD $4,500 could be explained by its use of a communist economic system for much of its recent history. The authors also predicted that communist nations who they believe have comparatively higher IQs, including the PRC, Vietnam, and North Korea, can be expected to gain GDP by moving from centrally-planned to market economic systems, while predicting continued poverty for African nations. Recent trends in the economy of the People's Republic of China seem to confirm this prediction, as China's GDP has quadrupled since market reforms in 1978.
[edit] Peer-reviewed papers using IQ scores from the book
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Like many books, IQatWoN's results were not peer-reviewed, but peer review has occurred in subsequent articles.
A review of the book in Contemporary Psychology (49 (4). pp389-395. Barnett, Susan M.; Williams, Wendy) stated: "In sum, we see an edifice built on layer upon layer of arbitrary assumptions and selective data manipulation. The data on which the entire book is based are of questionably validity and are used in ways that cannot be justified."
The book is sharply criticized in a peer-reviewed paper The Impact of National IQ on Income and Growth [1]. Although critical of the IQ data, for the sake of argument the paper assumes that the data is correct but then criticizes the statistical methods used, finding no effect on growth or income.
Another peer-reviewed paper with the same assumption, Intelligence, Human Capital, and Economic Growth: An Extreme-Bounds Analysis [2], finds a strong connection between intelligence and economic growth, although the paper makes no explicit claim that IQ explains most of the difference in growth between nations.
In a reanalysis of the Lynn and Vanhanen's hypothesis, Dickerson (in press) finds that IQ and GDP data is best fitted by an exponential function, with IQ explaining approximately 70% of the variation in GDP. Dickerson concludes that as a rough approximation "an increase of 10 points in mean IQ results in a doubling of the per capita GDP."
Whetzel and McDaniel (2006) conclude that the book's "results regarding the relationship between IQ, democracy and economic freedom are robust". Moreover, they address "criticisms concerning the measurement of IQ in purportedly low IQ countries", finding that by setting "all IQ scores below 90 to equal 90, the relationship between IQ and wealth of nations remained strong and actually increased in magnitude." On this question they conclude that their findings "argue against claims made by some that inaccuracies in IQ estimation of low IQ countries invalidate conclusions about the relationship between IQ and national wealth."
Voracek (2004) used the national IQ data to examine the relationship between intelligence and suicide, finding national IQ was positively correlated with national male and female suicide rates. The effect was not attenuated by controlling for GDP.
Barber (2005) found that national IQ was associated with rates of secondary education enrollment, illiteracy, and agricultural employment. The effect on illiteracy and agricultural employment remained with national wealth, infant mortality, and geographic continent controlled.
Both Lynn and Rushton have suggested that high IQ is associated with colder climates. To test this hypothesis, Templer and Arikawa 2006 compare the national IQ data from Lynn and Vanhanen with data sets that describe national average skin color and average winter and summer temperatures (see also discussion [3]). They find that the strongest correlations to national IQ were −0.92 for skin color and −0.76 for average high winter temperature. They interpret this finding as strong support for IQ-climate association. Templer and Arikawa 2006 is currently listed as the most downloaded article in Intelligence at ScienceDirect (Jan. - March 2006).[4] Other studies using different data sets find no correlation [5][6].
Kanazawa (2006), "IQ and the wealth of states" (in press in Intelligence), replicates across U.S. states Lynn and Vanhanen's demonstration that national IQs strongly correlate with macroeconomic performance. Kanazawa finds that state cognitive ability scores, based on the SAT data, correlate moderately with state economic performance, explaining about a quarter of the variance in gross state product per capita.[7]
[edit] Critique
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The figures were obtained by taking unweighted averages of different IQ tests. The number of studies is very limited; the IQ figure is based on one study in 34 nations, two studies in 30 nations. There were actual tests for IQ in 81 nations. In 104 of the world's nations there were no IQ studies at all and IQ was estimated based on IQ in surrounding nations.[8] The number of participants in each study was usually limited, often numbering under a few hundred. The exceptions to this were the United States and Japan, for which studies using more than several thousand participants are available.
Studies that were averaged together often used different methods of IQ testing, different scales for IQ values and/or were done decades apart. IQ in children is different although correlated with IQ later in life and many of the studies tested only young children.
Many nations are very heterogeneous ethnically. This is true for many developing countries. It is very doubtful that an often limited number of participants from one or a few areas are representative for the population as whole.
There are also errors in the raw data presented by authors. The results from Vinko Buj's 1981 study of 21 European cities and the Ghanaian capital Accra used different scaling from Lynn and Vanhanen's. A comparison of the reported to actual data from only a single study found 5 errors in 19 reported IQ scores [9][10].
As noted earlier, in many cases arbitrary adjustments were made by authors to account for the Flynn effect or when the authors thought that the studies were not representative of the ethnic or social composition of the nation.
There is controversy about whether IQ is a valid measurement of intelligence, especially among third-world populations. (See the article at IQ for details, as well as the article race and intelligence.) It is generally agreed many factors, including environment, culture, demographics, wealth, pollution, and educational opportunities, affect measured IQ. However, the origin of differences in IQ is disputed; according to those positing a partly genetic origin, non-hereditary factors account for anywher from 20-60% of the disparity [11]. Others posit an exclusively non-hereditary origin.
One common criticism is that many of the countries with the best average scores are those where testing (e.g. American SATs, baccalaureate examinations) is a crucial aspect of the educational process, and that many of these tests (esp. the SATs) have been shown to be very similar to IQ tests. In these nations, because students study extensively for the high-stakes examinations, it is quite possible that IQ scores are higher because people are subjected to frequent examinations for which they prepare extensively.
There are many difficulties when one is measuring IQ scores across cultures, and in multiple languages. First of all, use of the same set of exams requires translation, with all its attendant difficulties. To adapt to this, many IQ testers rely on both verbal tests, involving word analogies and the like, and non-verbal tests, which involve pictures, diagrams, and conceptual relationships (such as in-out, big-small, and so on). Roughly the same results tend to be gained with either approach.
The book reports a correlation between IQ and GDP. The book does not explicitly point out other factors which may directly cause the correlation. The Copenhagen Consensus points out that "iodine-deficient individuals score an average of 13.5 points lower in IQ tests." Countries with individuals plagued by iodine deficiency may have other factors depressing IQ, so this finding in isolation does not suggest that such a deficiency alone accounts for 13.5 IQ points. In this case, barring intervention, a nation's poverty may be self-sustaining in cases where successive generations cannot meet basic nutrition requirements.
Other factors may serve to heighten poverty while simultaneously decreasing IQ. For example, it is common for teenage children in sub-Saharan Africa to be the primary earners for their family. This is due to AIDS-related deaths of older caregivers. As children leave school to begin subsistence farming, their education ends and IQs will be markedly lower. The book does not adequately address the casual relationship of these outside factors to both poverty and intelligence.
Finally, the Flynn effect may well reduce or eliminate differences in IQ between nations in the future. One estimate is that the average IQ of the US was below 75 before factors like improved nutrition started to increase IQ scores. Some predict that considering that the Flynn effect started first in more affluent nations, it will also disappear first in these nations. Then the IQ gap between nations will diminish. However, to take a reductio ad absurdum, that the IQ difference will disappear among the babies born today, the differences will remain for decades simply because of the composition of the current workforce. Steve Sailer noted as much when discussing the workforce in both India and China (see second diagram) [12].
[edit] U.S. states and political party hoax
Some sources, such as The Economist, 15th-21st May 2004 (p.44 in the UK edition), have reported a list of average IQs of U.S. states, supposedly from IQ and the Wealth of Nations. In fact, such data do not appear in the book. At about the same time, conservative American commentator Steve Sailer exposed the table as a hoax that had already circulated among hundreds of liberal-leaning blogs and other Internet sites [13]. In the following week's edition of The Economist, the editors admitted their error and stated in the column On the trail that they "were the victim of a hoax." The hoax recurred after the 2004 U.S. election, and it was again falsely attributed to IQ and the Wealth of Nations [14], but the incident prompted yet another hoax—a claim that a computer scientist had compiled a genuine state-by-state chart using SAT and ACT scores [15]. This was allegedly compiled by Psychology "Professor Mark Jones, from Virginia Tech," who does not exist. While there is a faculty member by that name, he is an Assistant Professor in the computer science department [16]. Furthermore, no link to such a study, or evidence that he did such a study, has ever been provided.
Sailer and anthropologist Henry Harpending provide a list of mean IQs of U.S. states from 1960, arguing that the scores correlate reasonably with public school 8th graders' achievement test scores on the 2003 National Assessment of Education, and thus may be one of the closest data sets to a national sample of IQ scores (table here; discussion here, also see [17]).
[edit] End material
[edit] References
1. IQ and the Wealth of Nations Richard Lynn, Tatu Vanhanen Praeger, ISBN 0-275-97510-X
2. See [18]
3. International Monetary Fund reported 2004 per capita GDP (PPP). [19]
• Barber, N. (2005). "Educational and ecological correlates of IQ: A cross-national investigation". Intelligence 33 (3): 273-284.
• Dickerson, R. E.. "Exponential correlation of IQ and the wealth of nations". Intelligence In Press, Corrected Proof.
• Hunt, E. & Wittmann, W. (in press) Relations Between National Intelligence and Indicators of National Prosperity. Sixth Annual Conference of International Society for Intelligence Research, Albuquerque, NM. [20]
• Templer, D. I. and Arikawa, H. (2006). "Temperature, skin color, per capita income, and IQ: An international perspective". Intelligence 34 (2): 121-139.
• Voracek, M. (2004). "National intelligence and suicide rate: an ecological study of 85 countries". Personality and Individual Differences 37 (3): 543-553.
• McDaniel, M.A. & Whetzel, D.L. (2005). IQ and the Wealth of Nations: Prediction of National Wealth. Sixth Annual Conference of International Society for Intelligence Research, Albuquerque, NM. [21]
• Whetzel, D. L. & McDaniel, M. A.. "Prediction of national wealth". Intelligence 34: 449-458.
[edit] See also
• The Bell Curve
• Race and intelligence
• Economic inequality
[edit] External links
• "Intelligence and the Wealth and Poverty of Nations" - article by Lynn and Vanhanen
• PISA scores transformed into IQ values in comparison with IQ estimated by Lynn and Vanhanen
• Smart Fraction Theory of IQ and the Wealth of Nations
• Exponential correlation of IQ and the wealth of nations - Peer reviewed article to be published in an upcoming edition of Intelligence (journal)
• "The Bigger Bell Curve: Intelligence, National Achievement, and The Global Economy", review by J. Philippe Rushton
• "A Reader's statistical update of IQ & The Wealth of Nations"
• A Few Thoughts on IQ and the Wealth of Nations, Steve Sailer, VDARE, April 2002.
Retrieved from "http://en.wikipedia.org/wiki/IQ_and_the_Wealth_of_Nations"
