Chapter 1: Varieties of Intelligence
“By intelligence the psychologist”: Burt, Jones, Miller, and Moodie, 1934, p. 28.
“[Intelligence is] a very general mental”: Gottfredson, 1997, p. 13.
Experts in the field of intelligence: Snyderman and Rothman, 1988.
Developmental psychologist Robert Sternberg has studied: Sternberg, 2007b.
In addition, East Asian understanding of intelligence: Nisbett, 2003.
These include “working memory,”: Baddeley, 1986.
In addition, the subtests: M. J. Kane and Engle, 2002; Kazui, Kitagaki, and Mori, 2000; Prabhakaran, Rypma, and Gabrieli, 2001.
and another region linked: Rueda, Rothbart, McCandliss, Saccomanno, and Posner, 2005.
The destruction of the PFC has devastating consequences: Blair, 2006; Duncan, Burgess, and Emslie, 1995.
As one would expect given the lesion evidence: Blair, 2006; Prabhakaran, Rypma, and Gabrieli, 2001.
Additional evidence: Braver and Barch, 2002; Cavanaugh and Blanchard-Fields, 2006; Raz et al., 1997.
That fluid intelligence declines: Raz et al., 1997.
A final source of evidence: Jester et al., 2008.
Fluid intelligence is more important: Blair, 2006.
Over time, continued stress: Blair, 2006.
IQ tests tend to measure: Neisser, 1996; Sternberg, 1999, 2007a.
Robert Sternberg measures practical intelligence: Sternberg, 1999, 2006, 2007a.
Sternberg also writes about: Sternberg, 1999.
When Sternberg measures analytic intelligence: (Sternberg, 1999, 2006; Sternberg, Wagner, Williams, and Horvath, 1995.
Howard Gardner argued: Gardner, 1983/1993.
These include various “personal intelligences”: Lopes, Grewal, Kadis, Gall, and Salovey, 2006.
Emotional intelligence as measured by Salovey: Lopes, Grewal, Kadis, Gall, and Salovey, 2006.
Decades ago, personality psychologist Walter Mischel: Mischel, 1974.
Mischel then waited more than a decade: Mischel, Shoda, and Peake, 1988.
Psychologists Angela Duckworth and Martin Seligman: Duckworth and Seligman, 2005.
To these qualifications of the importance of IQ: Rothstein, 2004.
Political scientist Charles Murray has looked at people: Murray, 2002.
Murray himself has long been associated: Herrnstein and Murray, 1994.
Chapter 2: Heritability and Mutability
“75 percent of the variance [in IQ]”: Jensen, 1969, p. 1.
“Being raised in one family”: Scarr, 1992, p. 3.
Some still consider it: Bouchard, 2004, Plomin and Petrill, 1997.
This environmentalist camp estimates heritability: Devlin, Daniels, and Roeder, 1997; Otto, 2001; Stoolmiller, 1999.
The researchers I call the strong hereditarians: For example, see Bouchard, 2004.
Have a look at Table 2.1: Devlin, Daniels, and Roeder, 1997.
This figure is .74, and is essentially the one that Arthur Jensen: Jensen, 1969. If you are sophisticated in your knowledge about correlations but not about hereditability studies, you may wonder why the correlation of .74 is not squared in order to derive an estimate of the percent of variance accounted for by genetics. The answer is that genetic correlations are already squared.
This correlation is .26: Bouchard and McGue, 2003. Another estimate of the effect of the environment comes from the difference between the correlation between parents and the children they raised (.41) and the correlation between parents and their children who were raised by someone else (.24). This difference is .17, which is pretty close to .20. And we can compare the correlation for siblings reared together and who therefore share the same environment (.46), with the correlation for siblings raised apart and who therefore do not share the same environment (.24). This comparison gives us an estimate of .22, which is also pretty close to .20.
This is because when people: McGue and Bouchard, 1998.
Billy is likely to be raised: Bronfenbrenner, 1986, 1975/1999.
Developmental psychologist Urie Bronfenbrenner: Bronfenbrenner, 1975/1999, 1986.
When environments are dissimilar: Taylor (1980) also found that similarity of the environment makes a great deal of difference to the correlation of IQ between identical twins, but Bouchard (1983), using IQ tests different from those Taylor used, reached the conclusion that similarity of the environment does not make much difference to the correlation of IQ between identical twins.
Devlin and his collegues: Devlin, Daniels, and Roeder, 1997.
Once corrections are made: Devlin and his colleagues (1997) also want to subtract 20 percent from the heritability estimates, owing to what they claim is the common environment in the womb for twins. This has proved to be controversial, however, and it remains to be seen how important the womb-similarity factor is in contributing to the similarity in intelligence between twins.
Developmental psychologists Sandra Scarr: Dickens and Flynn, 2001; Flynn, 2007; Scarr and McCartney, 1983.
Psychologist Mike Stoolmiller: Stoolmiller, 1999.
First, the socioeconomic status (SES): Maughan and Collishaw, 1998; Verhulst, Althaus, and Versluis-den Bieman, 1990.
Stoolmiller calculated that: Stoolmiller, 1999. Behavioral geneticist Matt McGue and his colleagues (2007) studied adoptive and nonadoptive families and found evidence for only a modest range restriction on socioeconomic status (SES) and psychopathology for adoptive families as compared to nonadoptive families. In addition, they found little evidence that adoptive sibling correlations for IQ were any higher when they corrected for such range restriction than when they did not correct for range restriction. However, these findings have to be interpreted in light of two facts. (1) All of their families, including the nonadoptive ones, had two adolescent children living at home, and such families are more stable and are of a somewhat higher SES than families in general. (2) Mothers in nonadoptive families that refused to participate had dramatically lower education levels than did the mothers of the participating nonadoptive families. Thus, the nonadoptive families who participated in the study were of higher SES and were probably more stable than nonadoptive families in general. As we will see later, heritabilities for such high-SES families are substantially higher than for the population at large.
Since we know that within-family variation: Stoolmiller (1999) showed, however, that the failure to estimate correctly the degree of variation within families has led to an overestimation of the contribution of within-family variation to IQ, just as it has led to an overestimation of the contribution of heredity to IQ.
Psychologist Eric Turkheimer and his colleagues: Turkheimer, Haley, Waldron, D’Onofrio, and Gottesman, 2003. In other work, Turkheimer and others found a similar modification of heritability by social class (Fischbein, 1980; Gray and Thompson, 2004; Harden, Turkheimer, and Loehlin, 2006; Rowe, Jacobsen, and Van den Oord, 1999; Scarr-Salapatek, 1971). Other investigators failed to find this effect, however (Scarr, 1981).
Even when younger and older twins are sampled by the same method—typically by mailed questionnaire—and studied longitudinally, we would expect the subjects to be progressively harder to contact and to persuade to come to the testing site as they get older. This makes it likely that the older the subject is, the more likely the subject is to be of higher socioeconomic status—hence from a group with relatively high heritability.
We know from the work by Stoolmiller: Stoolmiller, 1999.
And in fact the environment: Turkheimer (personal communication) believes that the wide range of environments in lower-SES homes may be less important in determining low heritability than the fact that many such homes do not provide an environment sufficiently favorable for genes, and the differences among them from individual to individual, to express themselves.
This is because…there is a substantial bias: Dillman, 1978. This point applies to both major types of twin studies—those that estimate heritability based on the correlation between twins reared apart and those based on Falconer’s formula comparing the correlation between identical twins reared together with the correlation between fraternal twins reared together—2(MZ r–DZ r). Note that the middle-class response bias is observed in research in Europe, including Scandinavia and Holland, where some of the most frequently cited studies of adult heritability have been done (Bergstrand, Vedin, Wilhelmsson, and Wilhelmsen, 1983; Dotinga, Schrijvers, Voorham, and Mackenbach, 2005; Jooste, Yach, Steenkamp, and Rossouw, 1990; Sonne-Holm, Sorensen, Jensen, and Schnohr, 1989; Van Loon, Tijhuis, Picavet, surtees, and Ormel, 2003).
Psychologists Christiane Capron and Michel Duyme: Capron and Duyme, 1989.
So the study showed: Jensen (1997) attempted to minimize the implications of this very important study by saying that the correlation between g loadings of WISC subtests and the magnitude of the difference between biological parents and offspring are higher than the correlation between g loadings and the magnitude of the difference between adoptive parents and offspring. In other words, subtests that measure the genuine article, namely, g, the most show a relation for biological parents and offspring, and the less g-revealing subtests show a relation between adoptive parents and offspring. Many things can be said about this. (1) The difference in factor loadings on g across WISC subtests is relatively slight, so the reanalysis does not much affect conclusions about the impact of adoption on intelligence. (2) More importantly, there is no difference at all in average g loadings between the subtests that show a big difference between high-and low-SES adoptive parents and their offspring and those that show little difference. Both loadings are .71 on average. (3) The fact that the subtests that most differentiate between biological parents and their offspring have higher g loadings than the subtests that differentiate least is almost entirely due to the fact that the Coding subtest, which has by far the lowest g loading, is one of the tests that does not differentiate much between high-and low-SES biological parents and their offspring. If Coding is left out, the g loadings for the former average .79 and for the latter average .69—not much of a difference. (4) The WISC is a heavily verbally oriented test—that is, it measures mostly crystallized intelligence, and the g loadings differ primarily to the extent that they measure verbal ability as opposed to performance or fluid skills. (5) Jensen himself (1998) said that the purest measure of fluid g is the Raven Progressive Matrices test. If we examine fluid g as defined by subtest correlations with the Raven scores, we find that the correlation for biological parents and their offspring flips direction. It is now the tests with the highest g loadings that differentiate least between high-and low-SES biological parents and their siblings. So the question as to whether the genetic effect is more reflective of differences in g than the environmental effect is entirely a matter of deciding which is the real g—fluid or crystallized. See Flynn (2000a) for a more detailed explanation of these points in the context of race differences in IQ. More important than any of these points is that the adopted children of upper-middle-class parents did far better in terms of academic achievement than did the adopted children of lower-class parents. The results of their school achievement tests were substantially better and they were far less likely to be put back a grade. And Jensen has in other contexts expressed the view that academic achievement is highly reflective of g. In any case, we care more about school achievement than about IQ.
Another French study: Schiff, Duyme, Stewart, Tomkiewicz, and Feingold, 1978.
In another extremely important natural experiment: Duyme, Dumaret, and Tomkiewicz, 1999.
Stoolmiller showed: Stoolmiller, 1999.
A review that examined all: van IJzendoorn, Juffer, and Klein Poelhuis, 2005.
This estimate was derived by comparing: Hereditarians may complain that the IJzendoorn estimates (van IJzendoorn, Juffer, and Klein Poelhuis, 2005) of the effects of the adoptive-family environment are too high because they are based on young children and heredity exerts greater effects on older than on younger people—presumably because people are more able to choose their environments as they get older, and people with genes for higher IQ choose environments that will make them smarter. But IJzendoorn and colleagues (2005) found that age of testing—twelve years or younger versus thirteen to eighteen years old—made no difference to the estimate of the effects of adoption. This is the usual finding of the relationship between age and heritability. Heritability is constant from childhood to late adolescence (McGue, Bouchard, Iacono, and Lykken, 1993).
As it happens, the difference: Capron and Duyme, 1989.
The crucial implication of these findings: It is not just the IQ of children born to lower-SES parents that is highly modifiable by the environment. The IQ of children born to upper-middle-class parents is modifiable too. Such children have a much lower average IQ when they are raised by lower-SES parents, 12 points lower to be exact (Capron and Duyme, 1989).
The environments of adoptive families: Stoolmiller, 1999.
So the relatively low correlation: As noted in the text of Chapter 2, some people claim that the very low correlations for IQ found in adulthood between people adopted into the same family establish that such between-family environmental differences as may exist are gone by adulthood, when people have the ability to choose their own environments and their genetic potential can fully exert itself. Genetically smart people, the argument goes, seek out smarter environments, and less genetically smart people drift into less smart environments, so the childhood environment is no longer very relevant to contemporary IQ. However, the only sort of correlational study that would be reliable for this conclusion is a longitudinal one, where the correlation between adoptive siblings is observed from childhood through adulthood—for the same sample of individuals. This would remove the problem of researchers typically looking at children from higher-SES adoptive famiies when they look at adult samples than when they look at childhood samples. In fact, there appear to be only two longitudinal studies, and though they both show a reduction in the magnitude of correlations between childhood and adulthood, the samples are small and the differences between child correlations and adult correlations are not significant (Stoolmiller, 1999).
Finally, since Herrnstein and Murray: Herrnstein and Murray, 1994.
The actual value that Locurto: Locurto, 1990.
Judith Rich Harris, the author: Harris, 1998.
In his brilliant book: Pinker, 2002.
“Studies have shown”: Levitt and Dubner, 2006, p. 157.
One study looked at the IQs: Scarr and Weinberg, 1976.
Similarly, the cross-fostering study: Capron and Duyme, 1989.
Chapter 3: Getting Smarter
“even a perfect education system”: Murray, 2007a.
“a person’s total score”: Raven, Court, and Raven, 1975, p. 1.
The Bell Curve: Herrnstein and Murray, 1994.
Developmental psychologists Stephen Ceci and Wendy Williams: Ceci, 1991; Ceci and Williams, 1997.
Kids are deprived of school: Ceci, 1991; Jencks et al., 1972.
Much, if not most: Cooper, Charlton, Lindsay, and Greathouse, 1996; Hayes and Grether, 1983.
The very oldest study: F. S. Freeman, 1934.
Another early natural experiment: Sherman and Key, 1932.
School was delayed for Dutch children: DeGroot, 1948.
The IQs of such children: Ramphal, 1962.
The IQs of the children: R. L. Green, Hoffman, Morse, Hayes, and Morgan, 1964.
Two different groups of Swedish psychologists: Härnqvist, 1968; Husén, 1951.
In fact, studies in Germany and Israel: Baltes & Reinert, 1969; Cahan and Cohen, 1989.
Western-style education can have big effects: Ceci, 1991.
As little as three months: Ceci, 1991.
In America in 1900: Folger and Nam, 1967.
James R. Flynn has documented: Flynn, 1987, 1994, 1998.
In what follows I stick closely: Flynn, 2007.
Scores for eighteen-year-olds: Loehlin, Lindzey, and Spuhler, 1975.
And in any case, if completely test-naive people: Flynn, 2007.
For every child: Rutter, 2000.
The even gains across the distribution: Murray, 2007a.
The graph reveals: Flynn, 2007.
Developmental psychologist Clancy Blair: Blair, Gamson, Thorne, and Baker, 2005.
Developmental psychologist Wendy Williams: Williams, 1998.
Blair and his coworkers: See Blair and Razza, 2007.
But Figure 3.2 shows: Flynn, 2007.
Researchers have shown: C. S. Green and Bavelier, 2003.
Neuroscientists have shown: Jaeggi, Perrig, Jonides, and Buschkuehl, in press.
Researcher Rosario Rueda and her colleagues: Rueda, Rothbart, McCandliss, Saccomanno, and Posner, 2005.
As we might expect: Klingberg, Keonig, and Bilbe, 2002; Rueda, Rothbart, McCandliss, Saccomanno, and Posner, 2005.
The ADHD researchers: Klingberg, Keonig, and Bilbe, 2002.
Cognitive neuroscientist Adele Diamond: Diamond, Barnett, Thomas, and Munro, 2007.
Scores on two tests: Flynn, 2007.
Children can learn a lot: Johnson, 2005.
This seems understandable: National Endowment for the Arts, 2007.
On the other hand, we do know from other evidence: National Center for Educational Statistics, 2008. Tables and Figures: http://nces.ed.gov/quicktables/(retrieved August 14, 2008). 53 It is worth noting: Williams, 1998.
At the turn of the twentieth century: Blair, Gamson, Thorne, and Baker, 2005.
By 1983, more than: Williams, 1998.
It does seem to have come to a halt: Schneider, 2006.
In a particular region of Kenya: Daley, Whaley, Sigman, Espinosa, and Neumann, 2003.
A study on the Caribbean island of Dominica: Meisenberg, Lawless, Lambert, and Newton, 2005.
This seems inevitable: Johnson, 2005.
The gains in IQ make it clear: Lynn and Vanhanen, 2002; Rushton and Jensen, 2005.
Finally, the evidence speaks: Murray, 2007a.
He has also said: Herrnstein and Murray, 1994.
Chapter 4: Improving the Schools
U.S. students who score in the 95th percentile: U.S. Department of Education, 1998.
Such additional funds may be spent: Hess, 2006.
The classic case of this: Evers and Clopton, 2006.
Money by itself: Evers and Clopton, 2006.
Other evidence about the effect: Hanushek, 2002.
Such studies found as much as a one-third reduction: Howell, Wolf, Peterson, and Campbell, 2001.
When studies on the effects: Krueger, 2001; Krueger and Zhu, 2004; Ladd, 2002; C. E. Rouse, 1998.
Reasonable experiments: Bifulco and Ladd, 2006.
Unfortunately, charter schools: Hoxby and Murarka, 2007.
There is, however, some evidence: Hoxby, 2004; Hoxby and Rockoff, 2004.
The multiple-regression analysts: Hanushek, 2002.
On the other hand, economist Alan Krueger: Krueger and Zhu, 2004.
The children in the smaller classes: Krueger, 1999.
The effects persisted: Nye, Jayne Zaharias, Fulton, Achilles, and Hooper, 1994.
Indeed so, but the fact: Hanushek, Kain, O’Brien, and Rivkin, 2005; T. Kane, 2007.
Nor, surprisingly, is possession: Hanushek, Kain, O’Brien, and Rivkin, 2005.
The average difference in reading: Rockoff, 2004.
But note that most of the difference: Hanushek, Kain, O’Brien, and Rivkin, 2005; Jacob and Lefgren, 2005.
Defined in this way, 1 SD: Hanushek, Kain, O’Brien, and Rivkin, 2005; T. Kane, 2007; Rockoff, 2004.
Economist Eric Hanushek’s estimate of the impact: Hanushek, Kain, O’Brien, and Rivkin, 2005.
A study on the effects: Pedersen, Faucher, and Eaton, 1978.
Education researchers Bridget Hamre and Robert Pianta: Hamre and Pianta, 2001.
Hamre and Pianta found, in an earlier study: Hamre and Pianta, 2001.
Principals know about the quality: Armor, 1976; Murnane, 1975.
But there is little evidence: Hanushek, Kain, O’Brien, and Rivkin, 2005.
Researchers who are aware: De Sander, 2000.
A common complaint: Rosenholtz, 1985.
Israeli researchers conducted: Lavy, 2002.
Teachers in…and they monitor student performance: Connell, 1996.
The usual claim is that schools: Muijs, Harris, Chapman, Stoll, and Russ, 2004.
On the other hand: Muijs, Harris, Chapman, Stoll, and Russ, 2004.
Despite the hundreds of millions: Mosteller and Boruch, 2002.
Research is mostly anecdotal: Cook, 2003.
These studies generally yield: Borman, Hewes, Overman, and Brown, 2003.
Educational psychologist Geoffrey Borman: Borman, Hewes, Overman, and Brown, 2003.
A particularly well-designed: Borman et al., 2007.
The third-party comparison studies: See also particularly rigorous tests by Thomas Cook and colleagues (1999, 2000).
These computer software systems: Kulik, 2003.
Education researcher: Robert Slavin (Slavin, 1995).
Slavin reported studies: Slavin, 1995.
There are a variety of ways: Slavin, 1995.
In an extremely welcome development: U.S. Department of Education, 2008.
Herrnstein and his coworkers: Herrnstein, Nickerson, Sanchez, and Swets, 1986.
In fact, Mark Lepper and his colleagues found: Lepper, Drake, and O’Donnell-Johnson, 1997; Lepper, Wolverton, Mumme, and Gurtner, 1993; Lepper and Wolverton, 2001.
Chapter 5: Social Class and Cognitive Culture
“the class structure of modern”: H. J. Eysenck, 1973, p. 19.
The average IQ: Flynn, 2000b.
Although the available evidence: Pollitt, Gorman, Engle, Martorell, and Rivera, 1993.
It is not clear that nutrition differences: Rothstein, 2004.
Even if hunger is rare: General Accounting Office, 1999.
And there is evidence: Schoenthaler, Amos, Eysenck, Peritz, and Yudkin, 1991.
The effects of lead: Baghurst, 1992.
Children whose mothers drank: Centers for Disease Control and Prevention, 2007.
Lower-SES women: Streissguth, Barr, Sampson, Darby, and Martin, 1989.
Low birth weight: Hack, Klein, and Taylor, 1995.
Lower-SES mothers: Anderson, Johnstone, and Remley, 1999; U.S. Department of Health and Human Services, 2006.
For children with the most common: Anderson, Johnstone, and Remley, 1999; Caspi, 2007; Kramer, 2008; Luca, Morley, Cole, Lister, and Leeson-Payne, 1992.
One study finds: Der, Batty, and Deary, 2006. On the other hand, in one study (Kramer, 2008), mothers were encouraged to breast-feed exclusively, and this experimental study got the same results as the correlational studies.
Lower-SES people: Mills and Bhandari, 2003.
One such harmful circumstance: Rothstein, 2004.
Lower-SES children are more likely: Rothstein, 2004.
Compared with higher-SES parents: Dodge, Pettit, and Bates, 1994.
Developmental psychologist Vonnie McLoyd: V. McLoyd, 1998.
Early emotional trauma: Blair, 2006.
Income inequality in the United States: Economic and literacy statistics in this paragraph and the next come from a recent book on the American labor market by Richard Freeman (2007).
In contrast, the after-tax: Rothstein, 2004.
Reflecting the differences: Organisation for Economic Co-operation and Development, 2001.
The difference in reading and math skills: Micklewright and Schnepf, 2004.
In fact, the achievement gap: Ceci, 2007.
While their children: Lareau, 2003
Psychologists Betty Hart and Todd Risley: Hart and Risley, 1995.
Degree of encouragement: Brooks-Gunn & Markman, 2005.
Much of what we know: Heath, 1982, 1983.
Heath’s study was conducted…but more recent studies: Lareau, 2003; Mikulecky, 1996.
In what follows…recent work of Annette Lareau: Laueau, 2003.
A Philadelphia study: Neuman and Celano, 2001.
The IQs and skills of middle-income children: Cooper, Nye, Charlton, Lindsay, and Greathouse, 1996.
One study found: Burkham, Ready, Lee, and LoGerfo, 2004.
In fact, there is some evidence: C. Rouse, Brooks-Gunn, and McLanahan, 2005.
Chapter 6: IQ in Black and White
“The taboo against discussing race”: Sowell, 1994, p. 168.
“[Black] kids seem to”: Ogbu, 2003, p. 78.
A millennium earlier southern Europeans: Sowell, 1994, p. 156.
though Julius Caesar: Churchill, 1974, p. 2.
In this chapter and in Appendix B: Rushton and Jensen, 2005.
There is plenty of evidence: Steele, 1997; Steele and Aronson, 1995.
When the test is presented: Steele, Spencer, and Aronson, 2002.
At least as late as 1980: Jensen, 1980.
The correlation between brain size and IQ may be: Schoenemann, Budinger, Sarich, and Wang, 1999.
And according to a number of studies: These are reviewed in Rushton and Jensen, (2005).
In fact, however, there is no such correlation: Shoenemann, Budinger, Sarich, and Wang, 1999.
Moreover, the brain-size difference: Ankney, 1992.
And a group of people in a community in Ecuador: Guevara-Aguire et al., 1991; Kranzler, Rosenbloom, Martinez, and Guevara-Aguire, 1998.
The direction of recent evolution: Beals, Smith, and Dodd, 1984; Brown, 1992; Brown and Maeda, 2004; Henneberg, 1988; Henneberg and Steyn, 1993, 1995; Schwidetsky, 1977.
About 20 percent of the genes: Parra et al., 1998; Parra, Kittles, and Shriver, 2004.
It turns out that light skin color: Shuey, 1966.
Tested in later childhood: Eyferth, 1961.
But when a group of investigators: Witty and Jenkins, 1934.
The blood group assays: Scarr, Pakstis, Katz, and Barker, 1977.
Similarly, the blood groups: Loehlin, Vandenberg, and Osborne, 1973.
The hereditarians cite a study: Scarr and Weinberg, 1983; Weinberg, Scarr, and Waldman, 1992.
A superior adoption study: Moore, 1986.
Psychologists Joseph Fagan and Cynthia Holland: Fagan and Holland, 2002, 2007.
Indeed, black IQ now: Dickens and Flynn, 2006.
In fact, we know: Dickens and Flynn, 2006.
The shrinkage of the gap: Dickens and Flynn, 2006.
Black family income: Rothstein, 2004.
The unwed mother rate: Camarota, 2007.
Affirmative action has likely played: Thernstrom and Thernstrom, 1997.
Employers believe that young: Moss and Tilly, 2001.
When black and white job applicants: Darity and Mason, 1998; Darley and Berscheid, 1967.
The white applicants: Pager, 2003.
Already in 1965: Moynihan, 1965.
In 2005, for blacks age twenty-five to twenty-nine years old, the ratio of females to males: U.S. Census Bureau, 2006.
Since we know that more: Flynn, 1980.
As a consequence at least: U. S. Office of Personnel Management, 2006.
Race may be: Myrdahl, 1944.
African anthropologist John Ogbu: Ogbu, 1978, 1994.
The IQ differences between: Sowell, 1994.
These groups include whites: Ceci, 1991.
Ogbu focuses on: Ogbu, 1991a.
Unlike lower-caste minorities: Sampson, Morenoff, and Raudenbush, 2005.
Ogbu holds that: Ogbu, 1978.
In the case of American blacks: Ogbu, 2003.
Ogbu has written: For example, see Ogbu, 1991b.
In what follows I draw: Sowell, 1978, 1981, 1994; Flynn, 1991a.
In eighteenth-century Virginia: Sobel, 1987.
Though most free blacks: Sowell, 1978.
Eighty-five percent of free: Sowell, 1978.
In Chicago in 1910: Sowell, 1978.
To give an idea: Sowell, 1978.
The Irish, who were white: Ignatiev, 1995.
As of the mid-twentieth century: Macnamara, 1966.
English psychologist H. J. Eysenck: Eysenck, 1971.
The gene pool…and literary proficiency: Organisation for Economic Co-operation and Development, 2000.
Post–secondary school enrollment: Organisation for Economic Cooperation and Development, 2000.
The proportion of blacks: Attewell, Domina, Lavin, and Levey, 2004.
In 1970, second-generation West Indians: Sowell, 1978.
They took whatever jobs: Sowell, 1978; Waters, 1999
And West Indian culture: Sowell, 1978.
Sowell recently argued: Sowell, 2005. Sowell is worth quoting at length on this point. From page 6 of his book Black Rednecks and White Liberals: “The cultural values and social patterns prevalent among Southern whites included an aversion to work, proneness to violence, neglect of education, sexual promiscuity, improvidence, drunkenness, lack of entrepreneurship, reckless searches for excitement, lively music and dance, and a style of religious oratory marked by strident rhetoric, unbridled emotions, and flamboyant imagery.” From pages 1–2: “That culture long ago died out where it originated in Britain, while surviving in the American South. Then it largely died out among both white and black Southerners, while still surviving today in the poorest and worst of urban black ghettos.”
I pointed out: Hart and Risley, 1995.
Recall from the last chapter: Heath, 1982, 1983.
This probably pays off: Loehlin, Lindzey, and Spuhler, 1975.
In fact, those abilities: Heath, 1982.
In the late 1980s: Heath, 1990.
Meredith Phillips, Jeanne Brooks-Gunn: Phillips, Brooks-Gunn, Duncan, Klebanov, and Crane, 1998.
One came from a study: Chase-Lansdale et al., 1991.
The second data set came: Brooks-Gunn et al., 1994.
Things studied include: M. Phillips, Brooks-Gunn, Duncan, Klebanov, and Crane, 1998, pp. 126–127
Hart and Risley, in their study: Hart and Risley, 1995.
The three-year-old black child: Tough, 2007.
Recall the study: Moore, 1986.
These subcultures encourage: Patterson, 2006.
Chapter 7: Mind the Gap
“Compensatory education”: Jensen, 1969, p. 1.
“There is no evidence”: Jencks et al., 1972, p. 8.
“There is no reason”: Murray, 2007a.
It results in mortality rates: Ludwig and Miller, 2005.
In earlier days, Head Start: McKey, Condelli, Ganson, McConkey, and Plantz, 1985.
and more recent studies: Grissmer, Flanagan, and Williamson, 1998; Ludwig and Miller, 2005.
Recent reports show lower effect sizes: U.S. Department of Health and Human Services, 2005.
What little there is: Ludwig and Miller, 2005. One study found that the benefits of greater high school completion and college attendance are limited to whites: Garces, Thomas, & Currie, 2002.
The cost of Head Start: For a pessimistic review of the literature on Head Start, see Besharov, 2005. For a more optimistic review of Head Start, see Ludwig and Phillips, 2007. However, the latter relies on study designs that I consider inferior. Another optimistic study is by Deming, 2008.
Early Head Start: Love, 2005.
A review of about: Grissmer, Flanagan, and Williamson, 1998.
The Perry Preschool Program: Schweinhart et al., 2005; Schweinhart and Weikart, 1980, 1993.
These advantages include: Barnett, 1992.
The fact that gains: Knudsen, Heckman, Cameron, and Shonkoff, 2006.
An intervention even more ambitious: Garber, 1988.
A yet more intensive intervention: Campbell et al., 2001; Campbell and Ramey, 1995; C. T. Ramey et al., 2000; S. L. Ramey and Ramey, 1999.
One is important because: Herrnstein ad Murray, 1994.
Project Care, using methods: Wasik, Ramey, Bryant, and Sparling, 1990.
Another replication of Abecedarian: Gross, Spiker, and Haynes, 1997; Hill, Brooks-Gunn, and Waldfogel, 2003; The Infant Health and Development Program, 1990.
A particularly important fact: Gormley, Gayer, Phillips, and Dawson, 2005; Love et al., 2005.
and benefit poor children: Hamre and Pianta, 2005.
Some reasonably ambitious parenting interventions: Brooks-Gunn and Markman, 2005; Juffer, Hoksbergen, Riksen-Walraven, and Kohnstamm, 1997; van Zeigl, Mesman, van IJzendoorn, Bakersman-Kranenburg, and Juffer, 2006; Watanabe, 1998.
This was conducted: Landry, Smith, and Swank, 2006; Landry, Smith, Swank, and Guttentag, 2007.
The Heritage Foundation: Carter, 2000.
Richard Rothstein: Rothstein, 2004.
The Education Trust: Jerald, 2001.
Rothstein gives an even: Reeves, 2000.
The New York Times announced: Finder, 2005.
and yet again: Bazelon, 2008.
The black/white gap was actually: You can see the comparison of Wake County and statewide scores at the state’s education Web site: http://www.ncreportcards.org/src/distDetails.jsp?Page=2&pSchCode=304&pLEACode=920&pYear=2004-2005&pDataType=1
By the new standards: Data for 2005/06 math scores are more interpretable because the cutoffs for proficiency scores are much lower than for 2004/05. As in many states, what is labeled “proficient” in North Carolina bounces around from year to year depending more on politics than on actual student achievement. The 2005/06 data, when the required level for proficiency went up again, tell the same story. The Wake County black/white gap was no smaller than it was for the state as a whole. The Times writer would have done well to get his figures at the source rather than depending on data and interpretations offered by educators relying on the Wake County district reports.
There is good evidence: Murnane, Willett, Bub, and McCartney, 2006.
Experience in teaching counts, though: Sanders and Horn, 1996.
Again, there is the possibility: Sanders and Horn, 1996
And we know that: Hamre and Pianta, 2005.
We also know that: Grissmer, Flanagan, and Williamson, 1998.
The math training program: H. Phillips and Ebrahimi, 1993.
One study of Project SEED’s effectiveness: Webster and Chadbourn, 1992.
Reading Recovery is a tutoring program: Slavin, 1995.
The Ohio State group conducted randomized studies: Slavin, 2005.
One independent study evaluating: Slavin, 2005.
There is at least one extremely: All of the information about KIPP comes from a report by the Stanford Research Institute: David et al., 2006.
KIPP maintains that “while the average fifth-grader”: KIPP Web site, quoted in Mathews 2006.
However, SRI International conducted: David et al., 2006.
Principals believe: Quotations are from David et al., 2006.
The next step will be: Two other systems are similar to KIPP in design. One is called Achievement First and operates primarily in New Haven, Connecticut, and the other is called North Star and operates in Newark, New Jersey. These programs claim good results with children resembling the KIPP students. But they have not been well evaluated to my knowledge.
There’s good news: Jessness, 2002.
They showed, not surprisingly: Blackwell, Trzesniewski, and Dweck, 2007; Henderson & Dweck, 1990.
Dweck and her colleagues: Blackwell, Trzesniewski, and Dweck, 2007.
Dweck reported that some: Personal communication, January 2007
Joshua Aronson and his colleagues: Aronson, Fried, and Good, 2002.
One study was conducted: Good, Aronson, and Inzlicht, 2003.
Daphna Oyserman and her coworkers: Oyserman, Bybee, and Terry, 2006.
Social psychologists Gregory Walton and Geoffrey Cohen: Walton and Cohen, 2007. See also another effective, brief intervention by G. L. Cohen, Garcia, Apfel, and Master (2006).
Herrnstein and Murray: Herrnstein and Murray, 1994.
Blacks start out high school: Myerson, Rank, Raines, and Schnitzler, 1998.
Psychologist Joel Myerson and his coworkers: Myerson, Rank, Raines, and Schnitzler, 1998.
A third possible answer: Aronson and Steele, 2005; Steele and Aronson, 1995.
One study that followed: Osborne, 1997.
Another long-term study: Massey and Fischer, 2005.
The Nobel Prize–winning economist James Heckman: Heckman, 2006.
The initial cost: Besharov, 2007.
The same is true: Masse and Barnett, 2002.
Even when benefits: Dickens and Baschnagel, 2008.
As a yardstick for measuring: Institute on Taxation and Economic Policy, 2007.
The cost per pupil: Institute of Education Sciences, 2006.
Chapter 8: Advantage Asia?
In 1966, Chinese Americans: Flynn, 1991a, 2007.
In 1980—when they were: Flynn, 2007.
In the late 1980s: Caplan, Whitmore, and Choy, 1989.
In 1999, U.S. eighth-graders: National Center for Education Statistics, 2000.
Although Asian Americans constitute: Quindlen, 2008a.
Asian and Asian American students: Anonymous, 2007; Anonymous, 2008a.
So European Americans: Throughout the discussion in this chapter, my generalizations are meant to apply only to East Asians and not to South Asians. I believe that some of the generalizations apply to South Asians as well, but the evidence—and there is a lot of it—concerns East Asians primarily. When I refer to “Asians” or “Easterners” in what follows I always mean East Asians such as Chinese, Japanese, Koreans, and citizens of Taiwan, Singapore, and Hong Kong, all of whom have cultures that are Confucian historically and at base today.
Herrnstein and Murray: Herrnstein and Murray, 1994.
Rushton and Jensen: Rushton and Jensen, 2005.
Philip Vernon: Vernon, 1982.
Richard Lynn: Lynn, 1987.
but Flynn: Flynn, 1991a.
Most showed that East Asians: All comparisons that I am aware of between Asians or Asian Americans on the one hand and European Americans on the other show that Asian and Asian American scores on performance IQ tests, and especially visuospatial tests such as block design, are high relative to scores on verbal IQ tests, though the difference is usually slight. Herrnstein and Murray attribute this relatively greater performance ability of Asians to genetic differences, which certainly cannot be ruled out. On the other hand, as you will see later in this chapter, there are cultural differences that encourage attention to broad aspects of the visuospatial world more for Asians and Asian Americans. In addition, East Asian colleagues have told me that spatial problems resembling those found on IQ tests are taught in school to a much greater degree than is true in the West.
Harold Stevenson and his coworkers: Stevenson et al., 1990.
Even more astonishing: Stevenson and Stigler, 1992.
The Coleman report on educational quality: Flynn, 1991a.
Despite their slightly inferior: Flynn, 1991a.
By the age of thirty-two: Flynn, 1991a.
Recently, Flynn studied: Flynn, 2007.
And indeed they did: Flynn, 2007.
Asian and Asian American achievement: Nakanishi, 1982.
The high-school-age children: Caplan, Whitmore, and Choy, 1989.
Black eighth-grade children: Oyserman, Bybee, and Terry, 2006.
Asians today still believe: Chen and Stevenson, 1995; Choi and Markus, 1998; Choi, Nisbett, and Norenzayan, 1999; Heine et al., 2001; Holloway, 1988; Stevenson et al., 1990.
A team of Canadian psychologists: Heine et al., 2001.
But a still more important reason: Nisbett, 2003.
These East-West differences: My account of the social differences between Easterners and Westerners, as well as some of the resulting cognitive differences, is an abbreviation of points made in my book The Geography of Thought: How Asians and Westerners Think Differently…and Why. That book reports on historical and contemporary social and cognitive trends that differentiate Europeans and European Americans from East Asians and Americans of East Asian extraction. I refer you to that book for documentation of most of the assertions in this chapter about historical differences between Asians and Westerners and for detailed descriptions of a large number of studies on the perceptual and cognitive habits of contemporary people.
Takahiko Masuda and I: Masuda and Nisbett, 2001.
In another study, Masuda: Masuda, et al., 2008.
Chinese spend more time: Chua, Boland, and Nisbett, 2005.
Social psychologists have uncovered: Ross, 1977.
Koreans in this situation: Choi and Nisbett, 1998.
When we presented people: Ji, Zhang, and Nisbett, 2004.
We also presented: Norenzayan, Smith, Kim, and Nisbett, 2002.
My coworkers and I: Peng, 1997.
For example, when Chinese: Gutchess, Welsh, Boduroglu, and Park, 2006.
Consistent with this fact: Hedden, Ketay, Aron, Markus, and Gabrieli, 2008.
First, in several of the studies: Nisbett, 2003.
We found residents of Hong Kong: Ji, Zhang, and Nisbett, 2004.
And when Hong Kong residents: Hong, Chiu, and Kung, 1997.
The Japanese have spent: Organisation for Economic Co-operation and Development, 2007.
“I worked at the Carnegie Institution”: French, 2001.
Second, the Confucian tradition: Munro, 1969; Nakamura, 1964/1985.
In fact, the children: Watanabe, 1998.
Nils Bohr credited: Bohr, 1958.
Chapter 9: People of the Book
“[The Jews] are peculiarly”: Jewish Virtual Library, 2007.
“The United States today”: Sugar, 2006.
American Jews have received: Anonymous, 2008b; JINFO.ORG, 2008.
Approximately the same overrepresentation: Anonymous, 2008b; JINFO.ORG, 2008.
And 26 to 34 percent: Anonymous, 2003; Anonymous, 2008b.
In the United States, Jews: Freedman, 2000.
an approximately equal: Anonymous, 2003.
and about 30 percent: Anonymous, 2003.
According to the 1931 census: Statistics in this paragraph come from Marcus (1983).
Most reports place: Backman, 1972; Lesser, Fifer, and Clark, 1965; Levinson, 1959; Majoribanks, 1972.
If we assume an average IQ of 110: Incidentally, despite this difference in the probability of having an IQ of 140, the probability of a random Jew having an IQ that is higher than that of the average white non-Jew is only .75, assuming an average Jewish IQ of 110; assuming an average Jewish IQ of 115, the probability is .84. Such is the surprising outcome predicted by the elevation of the normal distribution curve at various degrees of distance from the mean.
It is important to note: Burg and Belmont, 1990; Ortar, 1967; Patai, 1977. Before leaving the topic of Jewish IQ, I should note that there is an anomaly concerning Jewish intelligence. The major random samples of Americans having large numbers of Jewish participants show that whereas verbal and mathematical IQ run 10 to 15 points above the non-Jewish average, scores on tests requiring spatial-relations ability (ability to mentally manipulate objects in two-and three-dimensional space) are about 10 points below the non-Jewish average (Flynn, 1991a). This is an absolutely enormous discrepancy and I know of no ethnic group that comes close to having this 20 to 25-point difference among Jews. I do not for a minute doubt that the discrepancy is real. I know half a dozen Jews who are at the top of their fields who are as likely to turn in the wrong direction as in the right direction when leaving a restaurant. The single ethnic difference that I believe is likely to have a genetic basis is the relative Jewish incapacity for spatial reasoning. I have no theory about why this should be the case, but I note that it casts an interesting light on the Jews’ wandering in the desert for forty years!
This is true even: Gross, 1978.
Complete elimination from reproduction: Loehlin, Vandenberg, and Osborne, 1975.
The geneticist Cyril Darlington: Darlington, 1969.
Political scientist Charles Murray: Murray, 2007b.
Anthropologists Gregory Cochran, Jason Hardy: Cochran, Hardy, and Harpending, 2005.
Fifteen percent of all scientists: Sarton, 1975.
Even within Europe: In his book Human Accomplishment Charles Murray (2003) documented the swings of achievement in different regions.
“It is counted a title”: Zweig, 1943/1987.
Psychologist Seymour Sarason: Sarason, 1973.
Chapter 10: Raising Your Child’s Intelligence…and Your Own
There is no evidence: Bruer, 1999.
The research suggesting: Bruer, 1999.
We find the same kind: Duyme, 1981.
Women who exercise: Clapp, Kim, Burciu, and Lopez, 2000.
The babies born to exercising: McDaniel, 2005.
Exercising large muscle groups: G. D. Cohen, 2005.
Experiments show that elderly: Colcombe and Kramer, 2003.
You can even start: Aamodt and Wang, 2007.
Breast-feeding beyond nine months: Mortensen, Michaelsen, Sanders, and Reinisch, 2002.
It seems to be particularly important: Anderson, Johnstone, and Remley, 1999.
The activities that increase: Klingberg, Koenig, and Bilbe, 2002; Mortensen, Michaelsen, Sanders, and Reinish, Oleson, Westerberg, and Klingberg, 2003.
Neuroscientist Rosario Rueda: Rueda, Rothbart, McCandliss, Saccomanno, and Posner, 2005.
Child neurologist Torkel Klingberg: Klingberg, Koenig, and Bilbe, 2002.
Similar exercises improved: If your child has attention deficit hyperactivity disorder, you may want to contact a specialist skilled in administering training like that used by Klingberg and his colleagues (2002). The list is available at http://www.cogmed.com/cogmed/articles/en/78.aspx
Finally, meditation exercises: Tang et al., 2007.
Personality psychologist Walter Mischel: Ayduk, Downey, Testa, Yen, and Shoda, 1999; Mischel, Shoda, and Rodriguez, 1989.
Recall that psychologists: Duckworth and Seligman, 2005.
We do know that if: Mischel, Shoda, and Rodriguez, 1989.
Also, Mischel and his coworkers had: Mischel, Shoda, and Rodriguez, 1989.
And Asians work harder: Heine et al., 2001.
When children are praised: Mueller and Dweck, 1998.
In a clever experiment: Mueller and Dweck, 1998.
With developmental psychologists Mark Lepper and David Green: Lepper, Greene, and Nisbett, 1973.
If a child has low: Calder and Staw, 1975; Loveland and Olley, 1979; V. C. McLoyd, 1979.
Epilogue: What We Now Know about Intelligence and Academic Achievement
First of all: Gottfredson, 1997.
Heuristics for reasoning: Nisbett, 1992.
Planning and choosing: Larrick, Morgan, and Nisbett, 1990; Nisbett, Fong, Lehman, and Cheng, 1987.