Bell Curve

7 28 Notes to pages 306-3 10107. The critique of Mercer's position has been highly technical. Readers whohave the patience will find an extended exchange between Mercer,Jensen, and Robert Gordon in Reynolds and Brown 1984.108. Mercer 1984, Tables 6,9; Jensen 1984b, pp. 580-582.109. Boykin 1986, p. 61.110. For review, see Boykin 1986.111. Ogbu 1986.112. Flynn 1984,1987a, 1987b.113. Merrill 1938.114. Flynn 1984, 1987b; Lynn and Hampson 1986c.115. Flynn 1987a, 1987b.1 16. Lynn and Hampson 1986a.1 17. Teasdale and Owen 1989.118. For evidence that this is what has happened in the United States, seeMurray and Hermstein 1992.1 19. If the mean IQ in 1776 had been 30 and the standard deviation was whatit is today, then America in the Revolutionary period had only five menand women with IQs above 100.E 20. Lynn and Hampson 1986a.121. Consider the analogy of height. The average stature of Americans hasrisen several inches since the Pilgrims landed at Plymouth, but heighthas run in families nevertheless.122. A shifting link between IQ and intelligence is not only possible but prohableunder certain conditions. For example, when the literacy level of acountry rises rapidly, scores on conventional intelligence tests will alsorise because more people will be better able to read the test. This rise isunlikely to be fully reflected in a rising intelligence level, at least withequal rapidity. Flynn 1987b discusses this general measurement issue.123. Scarr and Weinberg 1976, 1978, 1983; Weinberg, Scam and Waldman1992.124. Weinberg, Scarr, and Waldman 1992, Table 2. The progression of the IQmeans from two black parents to one blacklone white to two white parentsis not as neatly supportive of a genetic hypothesis as might first appear,because there is reason to suspect that the mixed-race biologicalparents of the adopted children were disproportionately drawn from collegestudents, which in turn would imply that the IQ of the black parentwas well above the black mean.125. Weinberg, Scam, and Waldman 1992. For the technical debate, see Levinin press; Lynn in press, with a response by Scarr and Weinberg in Waldman,Weinberg, and Scam in press.126. Weinberg, Scarr, and Waldman 1992, Table 2. The overall decline inscores for all groups was because a new test norm had been imposed inthe interim, vitiating the Flynn effect for this group.127. Waldman, Weinberg, and Scarr in press.128. Eyferth 1961 For accounts in English, see Loehlin, Lindzey, and Spuhler1975; Flynn 1980.129. Loehlin, Lindzey, and Spuhler 1975, Chap. 5.130. An earlier study showed no significant association between the amountof white ancestry in a sample of American blacks and their intelligencetest scores (Scarr et a!. 1977). If the whites who contributed this ancestrywere a random sample of all whites, then this would be strong evidenceof no genetic influence on black-white differences. There is noevidence one way or another about the nature of the white ancestors.131. Lewontin, Rose, and Kamin 1984.132. Scarr and Weinberg 1976, Tahle 12.Chapter 141. U.S. Department of Labor 1993, Table 3.2. U.S. Bureau of the Census 1993, Table 1.3. The NLSY sample does not include GEDs. Nationally, the 1991 highschool completion rate (signifying twelve years of school) was 87.0 percentfor whites, 72.5 percent for blacks, and 55.4 percent for Latinos (NationalCenter for Education Statistics 1993, p. 58).4. These results refer to a logistic analysis in which the dependent variablewas a binary variable representing obtaining a normal high school diploma.The independent variables were age and 1Q.5. For persons ages 25 to 29 in 1992, the proportions with bachelor's degreeswere 26.7 percent for whites, 10.6 percent for blacks, and 11.4 percent forLatinos (National Center for Education Statistics 1993, p. 62).6. Welch 1973.7. For example, given the mean years of education for people entering thehigh-IQ occupations defined in Chapter 3 (16.6) and holding age constantat the mean, the probability that whites would be in a high-lQ occupationwas 14.4 percent compared to 12.8 percent for blacks and 18.1 percent forLatinos.8. Gottfredson 1986.9. Gottfredson 1986 leaves room for the possibility that blacks at the upperend of the IQ distribution were disproportionately choosing medicine, engineering,or the other professions she happened to examine. Perhaps ifshe had examined other high-IQ occupations (one may hypothesize), shewould have found blacks represented at or below expectations. Our analy-