Bell Curve

Notes to pages 344-346 73334. See Jones 1992 on abortion, Abramson and Claggett 1991 on voting, andElliott and Ageton 1980 on delinquency.35. See the references (note 33) regarding ethnic differences in home environment.36. Refers to arrests for index crimes in 1992 relative to the size of the blackand white populations. Computed from Federal Bureau of lnvestigation1993, Table 43, and SAUS 1993, Table 22. See also Wilson and Hermstein1985, Chap. 18.37. U.S. Bureau of the Census 1993b, Table 305.38. R. Gordon 1976, 1987.39. We cannot use the NLSY self-report data for inter-racial comparisons. Selfreportcrime measures have consistently revealed marked differences in thewillingness of black and white youths to disclose crimes. See Elliott andAgeton 1980; Hindelang 1981; Hindelang, Hirschi, and Weis 1981.40. See the sixteen studies reviewed in Osbome and McGurk, 1982. See alsothe results from the Philadelphia delinquency cohort (Wolfgang, Figlio,and Sellin 1972).Chapter 151. We would, of course, need to know something about the fathers' scores too.The more complete account comes later in the chapter.2. Also see Ghiselin and Scudo 1986; Ingle 1973.3. Soloway 1982.4. Francis Galton's coined the term eugenic. See Galton 1883.5. The eugenicists were active, but, as we noted in the Introduction, the intelligencetesters were not. For an account of what happened prior to thepassage of the xenophobic and nativist Immigration Restriction Act of1924 and how it has gotten distorted in the retelling, see Snyderman andHermstein 1983.6. "Entrinsic birth rates" are birth rates corrected for age distributions. Deathrates also decline during the demographic transition, hut they will not hediscussed in any detail here. Demographers generally believe that differentialdeath rates cease to he a major factor in population growth in modernizedsocieties like ours. This is a supposition that needs to be reassessed,given the probable differential impact of infant mortalities, homicide rates,and AIDS in relation to tested intelligence. Of all the studies we summarizebelow, only Retherford and Sewell 1988 takes mortality rates into account,but it did not have a nationally representative sample to analyze. We maysurmise that the intergenerational decline in intelligence is heingmitigated somewhat by differential intrinsic death rates.7. Retherford 1986; Retherford and Sewell 1988; Vining 1986; Wrong 1980.8. Retherford 1986; Retherford and Sewell 1988.9. Becker 1981.10. E.g., Retherford and Sewell 1988; Rindfuss, Bumpass, and John 1980.1 1. Vining 1982a, Vining 1986.12. Vining 1986.13. For a sampling of studies that indicate the importance of attitudinal variahlesfor motherhood in many nations, see Booth and Duvall 1981; Hass1972; Krishnan 1990; Mason and Palan 1981; Youssef 1978.14. Estimating the phenotypic, as distinguished from the genotypic, change inintelligence across generations is conceptually little more than a matter oftoting up the population yielded across the distribution of intelligence,then aggregating the subtotals to get the overall distribution of scores inthe next generation, after first taking account of regression to the mean(Andrews 1990; Falconer 1966; Retherford and Sewell 1988). It is not necessaryto include any estimate for the heritability of intelligence. This simplicityin conception should not he confused with simplicity in actuallymaking these calculations. Parents in, say, successive deciles of intelligencemay have differing intrinsic rates of population growth (or decline) becauseof varying lifetime fertilities, varying ages at reproduction, and varyingmortality rates. Assortative mating by the parents (see Chapter 4)matters in calculation only insofar as it influences the correlation betweenparents and children. Hence, if fertility is lower at higher levels of intelligence,then assortative mating for intelligence will speed the decline of thepopulation intelligence because it increases the correlation between parentsand children. Some of the studies that we cite focus on the genotypicdecline rather than the phenotypic (e.g., Retherford and Sewell 1988).Since children resemble the parents who rear them for environmental reasonsas well as genetic, the population phenotype will change more rapidlythan the population genotype.15. The hest review of the early studies is Anastasi 1956. See also Duncan1952; Olneck, Wolfe, and Dean 1980; Retherford and Sewell 1988; Van-Court and Bean 1985; Vining 1986.16. Cattell 1936, Cattell 1937.17. Retherford and Sewell 1988.18. Cook, 195 1 p. 6.19. As Osbom and Bajema (1972) stated, "The distribution of births in an industrialwelfare-state democracy would become more eugenic as the environmentimproved with respect to health, educational, and occupationalopportunities, and particularly with respect to the spread of birth controlto the point where freedom of parenthood became a reality for all citizens"(p. 344). The Eugenic Hypothesis was first stated in Osborn 1940.