Grasping Reality on TypePad, by Brad DeLong

...Readers who wish to know about the current state of intelligence theory and research may be especially interested in the academic article “Intelligence: New findings and theoretical developments,” in the Feb.-March 2012 issue of American Psychologist, by Nisbett, R. E., Aronson, J., Blair, C., Dickens, W., Flynn, J., Halpern, D. F., and Turkheimer, E...

And:

Scott Lemieux: Charles Murray is a Hateful Crackpot Whose Views Should Not Be Legitimized - Lawyers, Guns & Money : Lawyers, Guns & Money: "Presenting Murray’s views as subject to reasonable debate... is extremely pernicious. To present him as a serious intellectual and victim of political correctness, as Harris apparently did, is simply beyond the pale..." http://www.lawyersgunsmoneyblog.com/2017/05/charles-murray-hateful-crackpot-whose-views-not-legitimized

I think the last word on Murray was said 22 years ago by the University of Chicago's Jim Heckman:

Jim Heckman: Cracked Bell http://reason.com/archives/1995/03/01/cracked-bell/: "It is striking that the authors do not discuss the costs and benefits of various interventions....

...It is in these terms that public policy discussions regarding skill-enhancement programs are usually conducted. The authors seek to short-circuit all of the hard work required to make credible cost-benefit calculations by claiming that there is a genetic basis for skill differences. But estimates of a genetic component of skills are irrelevant to the requisite cost-benefit analysis unless it can be established that all differences are genetic. No one, including the authors, claims that this is so.... Equally obvious is the point that knowing that all skill components are environmentally determined does not justify interventions.... The Bell Curve fails to present the hard information required to settle these matters on the factual grounds chosen by the authors.

This point is particularly telling for their assessment of education.... They acknowledge—and then go on to forget—that the relationship between education and ability is far from exact. In fact, throughout much of the book, they equate ability and education and implicitly assume that the economic returns to ability drive the economic returns to education.... This implicit assumption is false.... Ability and education are not the same thing, and both have economic rewards. Accounting for ability weakens but hardly eliminates the role of education in raising earnings....

What little is known indicates that ability—or IQ—is not a fixed trait for the young (persons up to age 8 or so).... Good environments promote learning for young children at all levels of ability.... The authors also disregard much recent empirical evidence by Richard Murnane and others that indicates the increasing returns to the measures used by Murray and Herrnstein account for only a small portion of the recent increase in the economic return to schooling. While payments for ability have increased somewhat in the past 15 years, there remains a substantial increase in the payment for education unrelated to the authors' measure.... It is unfortunate that the authors disregard this important evidence....

The third source of The Bell Curve's failure lies in the details of its analysis of the impact of ability on... earnings.... The credibility of any empirical study depends on the care taken by the analyst in defining and measuring concepts, and in interpreting conclusions drawn from the data. It is at this point that the book becomes a policy polemic rather than a scholarly study.... The authors delete from their composite AFQT score a timed test of numerical operations because it is not highly correlated with the other tests. Yet it is well known that in the data they use, this subtest is the single best predictor of earnings of all the AFQT test components.... It also drives home the point that the "g-loading" so strongly emphasized by Murray and Herrnstein measures only agreement among tests—not predictive power for socioeconomic outcomes.... More disturbing is the authors' treatment of family background.... It would be incredible if 15 to 23 years of environmental influences, including the nurturing of parents, the resources they spent on a child, their cultural environment, their interaction with their children, and the influence of the larger community could be summarized by a single measure of education, occupation, and family income in one year.... The authors have no good way to separate genetic from social influences on social behavior. Their environmental data are too crude and the AFQT score they use is obtained too late in life to make a genetic-environmental distinction meaningful. The authors would require much finer measures of environmental variables than they have at their disposal to rule out the importance of family and society in determining individual outcomes...

The authors present evidence that IQ rises with age and with years of schooling completed. IQ may actually be a better measure of the environment facing children than the measure of environment used by Murray and Herrnstein. They use IQ to predict schooling, but schooling produces IQ. Hence, they are especially likely to find a strong measured effect of "IQ" on schooling. The same remarks apply to their study of racial and ethnic differentials in socioeconomic outcomes. If racial differentials in environments affect ability and influence measured test scores, evidence that racial differentials weaken when ability is controlled for using regression methods does not rule out an important role for the environment in explaining performance in society. In the presence of measurement error in the environment, the authors' analysis will overstate the "true" effect of ability on those outcomes.

There are methods for addressing these problems, but Murray and Herrnstein do not use them. They should have tried a variety of measures of family background to explore the sensitivity of their reported results to the particular measures of family background they do use. A strict environmentalist could justifiably argue that the evidence reported by Murray and Herrnstein simply reveals the crudity of their measure of the environment and the strength of the correlation between the test score and their measure of environment.

One important technical point worth making here concerns the method used by the authors to measure standardized changes in IQ and family background. By its very construction as a measure that follows a bell curve, the "two-standard deviation" range in measured IQ used by the authors to gauge the sensitivity of outcomes to IQ represents a change in IQ ranging over 95 percent of the population. A "two-standard deviation" range of their family background index does not include 95 percent of the population, because that measure does not come from a bell curve. It may include as little as 75 percent of the population. By restricting the range of the environmental variable they understate the role of the environment in affecting outcomes relative to the role allocated to IQ.

Finally, the book fails due to a lack of coherence. The argument does not cumulate in a convincing way. Too many seams are visible. Its case against affirmative action and egalitarianism in education, and in favor of the use of testing in the workplace, does not require acceptance of a single ("g-loaded") scale of ability, or acceptance of the importance of heredity in producing socioeconomic inequality. The authors' evidence of growing stratification by cognitive ability in schools and workplaces does not require that they take a position on how the ability is produced. Yet the authors argue strenuously for their narrow view of ability and its heritability and thereby distract the reader's attention.

Nor do the two competing visions of the future of American society offered up in Part IV naturally flow from the arguments and evidence presented in the earlier parts of the book. The first dystopic vision relies on stronger sorting and heritability mechanisms than the authors have demonstrated actually operate in American society. Even if IQ is largely inherited, there is considerable scope for intergenerational economic mobility. The extreme pessimism of this scenario ignores the warnings issued by the authors that even among persons in the lowest ability grouping, there is still a lot of socially productive behavior. Their pessimistic vision relies on unsupported assumptions about the skill bias of future technological change and the inability of entrepreneurs—and social institutions—to efficiently utilize unskilled labor. This vision might be realized, but it reads more like a story borrowed from science fiction novels than a plausible extrapolation of existing social trends....

To the extent that social interventions can upgrade skills, they are most likely to be effective when they are applied to the young. The fragments of evidence summarized in Chapter 17 of the book, and other evidence from high-intensity enriched-environment programs, point in this direction. This evidence is also consistent with the work of Thomas Sowell, who stresses the role of culture and values in shaping the expectations and motivations of young children. Job training and education are generally wasted on low-IQ adults. For this group, subsidies for employment may be justified, especially if work improves social behavior or is valued for its own sake. Economic efficiency is promoted by investing in the young. There is much evidence that learning is a cumulative, dynamic process. Learning begets learning. It is much easier to galvanize a young child than an illiterate young adult...

If I were the family of William H. Brady, I would ask for my money back from AEI. Just saying...