Written throughout four years of extensive research by Richard Herrnstein and Charles Murray, The Bell Curve: Intelligence and Class Structure in American Life is a comprehensive treatment of its stated subject matter. It uses massive amounts of data on intelligence in the American population to present multiple analyses of the effects of intelligence on American social structure. From these varied analyses, Herrnstein and Murray present their argument for how to preserve the American ideal in the face of the effects of intelligence on American life.
The book opens with a simple introduction to the concept of intelligence and the research surrounding it. The authors clearly point out the dichotomy between the perceived wisdom on intelligence and the scholarly knowledge. They conclude by defining their basic terms and the scientific conclusions that they operate from for the rest of the book. Part I deals with the development of what the authors call a "cognitive elite". They detail how the most intelligent people in American life are, through the educational system, becoming stratified and isolated from the rest of society. Part II details the strong relationships between intelligence and social behavior, especially the elements of society that most consider distasteful: poverty, crime, welfare, and so on. The authors show that intelligence has a huge, unconsidered relationship to most social phenomena -- a relationship that must be taken into account to fully deal with these problems. Part III considers intelligence in the national and demographic sense. This is the most controversial aspect of the book, as it deals with the ethnic differences of intelligence, and then discusses the possibility of dysgenic pressure (the possible future decreases of intelligence.) In Part IV the authors discuss the meaning of all their conclusions and possible solutions to the problems they present. They present in the final chapters their vision of a free and equal America, and how this vision can be realized in the face of their overwhelming data and the effects of intelligence on American society.
Herrnstein and Murray begin their work by attempting to dispel many myths
about intelligence. They show that the popular wisdom surrounding the concept of intelligence is completely contrary to the state of scientific
knowledge (giving multiple sources to verify this assertion
). They give a brief history of intelligence and the science of psychometrics
(the study and measurement of the human mind), which they then use to define the terms and foundations for the rest of The Bell Curve
. Among these they give six statements, which they regard as beyond scientific dispute (i.e. already shown true beyond reasonable doubt) and as fundamental
to the rest of their work. These are:
There is such a thing as a general factor of cognitive ability on which human beings differ.
All standardized tests of academic aptitude or achievement measure this general factor to some degree, but IQ tests expressly designed for that purpose measure it most accurately.
IQ scores match, to a first degree, whatever it is that people mean when they use the world intelligent or smart in ordinary language.
IQ scores are stable, although not perfectly so, over much of a person's life.
Properly administered IQ tests are not demonstrably biased against social, economic, ethnic, or racial groups.
Cognitive ability is substantially heritable, apparently no less than 40 percent and no more than 80 percent.
These statements underlie the rest of The Bell Curve and are necessary truths to make its analyses valid. It is important to note: throughout the scientific community at large, these statements are beyond scientifically valid dispute.
Part I : The Emergence of a Cognitive Elite
The first part of The Bell Curve discusses the effects of intelligence at the top of the cognitive ability distribution. Chapter 1 begins by examining the educational factor. By analyzing standardized test data and college admissions records, it becomes clear that over the past 50 years, the determining factor in college attendance (both in general and for specific schools) is, rather than social class or wealth, overwhelmingly the intelligence of the student. This selection for cognitive ability stratifies the most intelligent of the population by placing them all in the same place at once: college. The next chapter discusses the same stratifying effect in the workplace. Through educational credentials and the need for intelligence in certain jobs, the partitioning effect continues in many professions. These include teaching, engineering, law, research, architecture, medicine, and accounting. Through the educational system, the most intelligent students are siphoned into these occupations, keeping them near other bright people and apart from the majority of the population for the rest of their lives.
Chapter 3 deals with the economic reasons that these systems have come into being. Put simply, intelligence is the single most powerful predictor of job success, and by extension, workplace productivity. A smart person has a much greater dollar value than an average one for a business owner. The statistics in this chapter are some of the most startling in the entire book. For example, a person who has an IQ of 115 is approximately 80% more productive than a person with an IQ of 100 (on the average.) This is not a large difference in dollars for a job stocking shelves at Wal*Mart, but for an engineer designing the newest medical technology, it is an enormous factor. Thus the pressure to select for intelligence in business is both valid and unavoidable. The final chapter of this part deals with the possible results of the cognitive partitioning system. Because of the strong pressure to partition in both education and the workplace, Herrnstein and Murray predict that intelligence will soon become the basis for a full-blown American class system, with all the consequences that implies.
Part II : Cognitive Classes and Social Behavior
The second part of The Bell Curve deals with the social behaviors that educated society normally considers undesirable (poverty, crime, unemployment, illegitimate children, etc.) The authors note that social scientists have previously almost ignored intelligence in their analyses of social behavior. However, an analysis of the data on cognitive ability leads Herrnstein and Murray to conclude that it is intelligence, rather than simply socioeconomic status, that is the cause of all these social effects. In addition, they find that when intelligence is taken into account, it either nearly eliminates or reverses the accepted trend of these behaviors in comparison to other "effects". This leads the authors to rightly conclude that any study of social policy relating to these behaviors is decidedly incomplete without taking account for the effects of intelligence.
Poverty is the first issue the authors deal with. Via multiple regression analyses, they clearly show that intelligence is far more important than childhood socioeconomic status when predicting the economic welfare of a person later in life. In their succinct terms, it is "better to be born smart than rich." The story is similar for the educational perspective, particularly for high school. A person with high IQ is extremely likely to finish high school regardless of their economic circumstances, whereas someone of low cognitive ability who comes from a wealthy family is not nearly so inclined. The same pattern is repeated on a lesser scale for post-secondary education. The study of unemployment is one of the most telling in this part of the book. It shows that for unemployed men, the greatest risk factor in predicting unemployment is not socioeconomic background or education, but instead intelligence. The same applies to men out of the labor force for reasons of injury or disability. The prediction is by far the strongest in terms of cognitive ability. The eighth chapter is entitled "Family Matters" and discusses the status of the American family when viewed in light of intelligence data. The conclusions, in short, are frightening. While among the average and higher levels of intelligence, the traditional American family is still strong and stable, in the lower classes of intelligence the nuclear family is all but destroyed. The "decay" of the American family is almost entirely based on the effects of intelligence.
Chapter 9 deals with the relationship of welfare and intelligence. The story is again much the same, although less clear than on previous topics. Cognitive ability is the primary factor in predicting temporary welfare dependency, regardless of previous socioeconomic status. However, unlike previous subjects, chronic welfare dependency is more subject to childhood dependence on welfare or childhood poverty. This lends credence to the "culture of poverty" argument, but there is a bit more to the story. Among those who have low socioeconomic status as children, those in the upper portion of the intelligence distribution are able to rise out of the "poor culture" and avoid welfare for the rest of their lives. The next chapter focuses on parenting, specifically the question of whether intelligence affects the ability of parents to raise their children well. The data shows two clear conclusions. First, high intelligence is not a prerequisite for being a good parent -- those with average intelligence make fine and even excellent parents in the majority of circumstances. Second, however, is that the most damaging homes and family environments exist in those places where the parents are on the low end of the cognitive ability distribution.
Crime is the next subject that Herrnstein and Murray discuss. It is well known, and well documented, that the criminal element has a lower intelligence than the average population. The average criminal has an intelligence about 8 points lower than the average American, with the career or chronic criminal differing by far more. The authors also show that those with high intelligence, even if they come from high-risk backgrounds, are far less likely to commit crime than those of average or low intelligence. The final topic in this part of The Bell Curve is civility and good citizenship. Measuring this quality with several methods, the authors show that intelligence strongly correlates with a person's values. Those people with higher intelligence are more likely to have qualities considered to be virtuous or morally good -- in short, to be a good citizen.
Part III : The National Context
This part deals with the ethnic differences in intelligence, the effect of intelligence on typical comparison of ethnic groups, and with the effects of differing fertility patterns on the intelligence distribution as a whole. The first chapter takes some time to establish that there are definite, measurable, significant differences in intelligence between various ethnic groups. The authors also take some space to dispel the myths about ethnic bias in intelligence testing (which they do in great detail in the Appendices.) The next chapter proceeds to examine ethnic inequalities when intelligence is taken into account. The results are interesting. In education and entry into the high-level workforce, the gap between white and black reverses after intelligence is accounted for. However, even when intelligence is accounted for in the analysis, unemployment, wage earnings, and other topics still contain a sizable racial gap. Intelligence is part, but not all, of the picture.
Chapter 15 deals with the demography of intelligence. The conclusions seem small in nature, but may have far-reaching consequences. In short, because of changing immigration trends and the tendency of low-IQ mothers to have children first, the intelligence distribution is experiencing pressure downward over time. This amounts to a fraction of a point per year, but, as the authors show, even a change of a few points could be expected to yield massive and disruptive effects. The last chapter in this part shows that among those who experience social problems, the vast majority is in the low segment of the intelligence distribution. Regardless of the causal possibilities, the prevalence measurement is indisputable. Thus, solutions to any social problems should be engineered to help those who have less cognitive ability than most of the population.
Part IV : Living Together
This final part of the book contains the authors’ recommendations for using the analyses they have presented thus far. They apply their conclusions to social policy in America and then present their vision for the future. Chapter 17 discusses the methods available to raise intelligence across the distribution. The data, unfortunately, shows little success. The most important environmental factor in raising intelligence appears to be nutrition, which has steadily improved across the past century but has begun to plateau in recent years. Herrnstein and Murray call for additional research in this area -- but research that is not afraid of discovering what may be the hard truth. The following chapter analyzes the state of American education. The conclusion is straightforward: The American educational system has done well in helping the disenfranchised and the underprivileged -- but at the expense of the gifted few who will be the movers and shakers of future society. They suggest, that beginning in government, American society reemphasize academic excellence, with the hope of motivating the gifted student to excel and therefore to produce. Chapters 19 and 20 take a hard look at affirmative action in higher education and the workplace, and find it lacking. The available data shows that affirmative action is not serving its intended purpose and that it could not stand up to a full, rigorous public scrutiny.
The penultimate chapter is entitled "The Way We Are Headed". In this chapter, the conclusions of the previous parts are drawn into a dire, but accurate, prediction of the future. The authors predict that due to economic pressure, the isolation of the cognitive elite will continue. The underclass, increasingly determined by cognitive ability, will become increasingly mired in poverty and crime. And because the intelligent are the active and affluent, they will begin to restructure society so that they can no longer lose, and so that the underclass, by extension, can no longer win. In the final chapter, however, the authors present their vision. They reject the concept of an egalitarian society that compensates for individual differences through socialism or a welfare state. They lay out the doctrine of a "valued place", stating their belief that any person can have a happy life if he or she has a happy family, a community of peers to interact well with, and a fulfilling position in the workforce. This, Herrnstein and Murray argue, is the correct vision for an equal and free America.
Soon after the publication of the first edition of The Bell Curve, Murray wrote an afterword to respond to many of the ridiculous criticisms of the book. This afterword is included in later editions and lays out exactly why the most prominent detractors of the book (Stephen Jay Gould) are wrong, and what the effects of The Bell Curve may be far into the future. Murray predicts that the reexamination of these issues that The Bell Curve has prompted may be its most important achievement.
The authors include several appendices, which are self-explanatory to any reader of the book. The book concludes with its bibliography and comprehensive chapter-by-chapter notes. The appendices are:
Statistics for People Who Are Sure They Can't Learn Statistics
Technical Issues Regarding the National Longitudinal Survey of Youth
Technical Issues Regarding the Armed Forces Qualification Test as a Measure of IQ
Regression Analyses from Part II
Supplemental Material for Chapter 13
Regression Analyses from Chapter 14
Beyond Scientifically Valid Dispute
There is a knee-jerk reaction to the phrase "beyond scientifically valid dispute" that misinterprets the meaning of the phrase and distorts the intent of its use. This particular phrase means, in effect, that no scientist will be able to use data to challenge a particular claim. Such a phrase (see also "beyond significant technical dispute") is only applied to conclusions that have been rigorously established by decades of research. This is definitely the case for the six assertions The Bell Curve makes in its introduction. Since the most publicized and ringing indictments of the book are based on these, some qualification is in order.
Now, it is certainly possible to argue with any of these principles: they are not self-evident. However, any degree of research into the topics in the technical literature will show that these claims are not disputed by the scientific community at large. This is because the data clearly shows these conclusions. To analogize: it would be possible for a physicist to challenge the Laws of Thermodynamics, but he would be a laughingstock in the scientific community because he could not produce any data.
This is the case with Stephen Jay Gould's argument against The Bell Curve. He presents what is known as the "factor-analytic argument" against the very concept of g. This argument, unfortunately for him, was scientifically discredited decades ago. In fact, when he re-raised the issue in his review of The Bell Curve, there was significant response from the scientific community. Fifty-two experts in the fields of psychology (note: Stephen Jay Gould was an evolutionary biologist and paleontologist) wrote a public letter supporting every one of The Bell Curve's major claims. This letter, entitled Mainstream Science on Intelligence, was published in the Wall Street Journal on December 13, 1994.
It is sufficient for me to elucidate the meaning of this phrase and mention "Mainstream Science on Intelligence". I strongly encourage those who desire the facts to do their own research in the techinical literature of the field. Your findings will totally validate any of the six claims that The Bell Curve (and I) claim are "beyond scientifically valid dispute".
The Bell Curve is an extremely controversial book that happens, like The Origin of Species before it, to be based in indisputable science. Thousands have denounced the book as evil, ignorant, and racist. It is none of these things. I enjoin any who think this to read to book carefully, referring to the sources cited by the authors whenever they are unsure. As Murray says in the Afterword, "you will find the exercise instructive."
Richard Herrnstein, Charles Murray.
The Bell Curve.
New York City: Simon & Schuster, 1994.
"Mainstream Science on Intelligence."
The Wall Street Journal.
New York City: Dow Jones & Company, 1994. (Public Domain Work.)
Personal knowledge, learning, and consultation with professors in the field.