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Date:
What Is Intelligence, and Who Has It? October 16, 1994, Sunday, Late Edition - Final
Byline:By Malcolm W. Browne;
Lead:THE BELL CURVE Intelligence and Class Structure in American Life. By Richard J. Herrnstein and Charles Murray. Illustrated. 845 pp. New York: The Free Press. $30.
Text:RACE, EVOLUTION, AND BEHAVIOR A Life History Perspective. By J. Philippe Rushton. Illustrated. 334 pp. New Brunswick, N.J.: Transaction Publishers. $34.95. THE DECLINE OF INTELLIGENCE IN AMERICA A Strategy for National Renewal. By Seymour W. Itzkoff. 242 pp. Westport, Conn.: Praeger. $49.95.
ONE may loathe or share the opinions expressed in the three books under review, but one thing seems clear: The government or society that persists in sweeping their subject matter under the rug will do so at its peril.
The issues raised by the scholars who wrote these books bear intimately on America's near future: its quality of life, its citizens' sense of belonging, its economic survival and the very foundations of a democratic society. They believe that America is rapidly evolving a huge underclass, an intellectually deprived population of men and women whose cognitive abilities will never match the future needs of most employers and for whom American society seems to have less use each year. The prisoners of this new underclass, the authors fear, may be permanently doomed by their intellectual shortcomings to welfare dependency, poverty, crime and lives shorn of any hope of realizing the American dream.
The numbers are far from encouraging. Indicators of national intelligence in the United States have declined compared with similar measurements of intelligence in other countries. The demographer Daniel R. Vining Jr. has calculated that America's I.Q. scores have fallen about five points since intelligence tests first came into use at the beginning of this century, and the College Entrance Examination Board says that scores for the Scholastic Aptitude Test fell from 1962 to 1990 by 11 percent in the verbal section and 5 percent in the mathematics part. The Educational Testing Service does not call the S.A.T. an intelligence test, but the test is nevertheless supposed to measure something like native brainpower.
Worst of all, say the authors, the lowest intellectual levels of the population are strongly outbreeding the brightest, and if (as most psychologists believe) intelligence is partly inherited, America is losing the cognitive base essential to coping with national problems.
In "The Bell Curve: Intelligence and Class Structure in American Life," Richard J. Herrnstein and Charles Murray write, "Mounting evidence indicates that demographic trends are exerting downward pressures on the distribution of cognitive ability in the United States and that the pressures are strong enough to have social consequences." It makes little difference whether people at the low end of the intelligence scale pass on their deficit genetically or environmentally, they say: "If women with low scores are reproducing more rapidly than women with high scores, the distribution of scores will, other things equal, decline, no matter whether the women with the low scores came by them through nature or nurture."
This thesis becomes especially unpalatable when one considers the authors' observation that a large proportion of this emergent underclass is black. Unless future accommodations between ethnic groups lead to a more harmonious social structure, Mr. Herrnstein and Mr. Murray say, the potential for racial hatred seems enormous.
However much one may disagree with this assessment, the possibility that the authors may be even partly right makes these three books worth plowing through and mulling over. The articulation of issues touching on group intelligence and ethnicity has been neither fashionable nor safe for the last three decades, but these scholars argue that the time has come to grasp the nettle of political heresy, to discard social myths and to come to grips with statistical evidence.
The authors suggest that unless we do something to correct present trends, America may soon be permanently split between an isolated caste of ruling meritocrats on one hand and a vast, powerless Lumpenproletariat on the other. Society, the authors predict, will have little use for this underclass in a world dominated by sophisticated machines and the bright human beings who tend them.
This grim future may already be unavoidable.
Seymour W. Itzkoff, whose book "The Decline of Intelligence in America: A Strategy for National Renewal" is the gloomiest of the group, writes: "Our problem is simple, but oh-so-difficult to discuss, let alone accept. We are a different people than we were 50 years ago. In truth, we are not the nation that we were. Relative to the rest of the developed and developing world, we probably no longer have the intellectual capital that can profit from the available educational resources."
These books are heavily laced with statistics, bibliographic citations and ideas requiring time to consider, and they are not light reading. The authors of "The Bell Curve" tell readers that they may limit their perusal to the summaries that precede each chapter, and that they may skip the main text. Still, "The Bell Curve" is 845 pages long, and a reader who skips even the appendixes will miss many of the points the authors are at pains to make.
The writers of these works are recognized by colleagues as serious scholars. Mr. Herrnstein, who died from lung cancer at the age of 64 this September, just before publication of "The Bell Curve," was a professor of psychology at Harvard University; Mr. Murray, a fellow at the American Enterprise Institute whose views influenced the Reagan White House, is the author of "Losing Ground: American Social Policy 1950-1980"; J. Philippe Rushton, the firebrand of the quartet, is a professor of psychology at the University of Western Ontario, and Mr. Itzkoff is a professor of education at Smith College.
Although their books vary in viewpoint, the authors share a suite of controversial convictions. They believe that intelligence in some deep but ill-defined sense is a real attribute of human beings, not some artificial construct of the psychometricians who invented intelligence tests. (Mr. Itzkoff's loose definition of intelligence, very similar to that of the other authors, is expressed as the capacity "to think abstractly, to reason. . . . to organize large quantities of information into meaningful and useful systems.")
They believe that I.Q. can be quantitatively measured, and that intelligence is at least partly heritable. They say that numerical measurements of intelligence are statistically (albeit weakly) correlated with job performance, as well as with rates of birth, marriage, divorce, illegitimacy, crime, welfare dependency and participation in the political process.
MOREOVER, they say, intelligence test scores tend to vary with ethnic groups. In the United States, Asians generally score a few points higher than whites and blacks some 15 I.Q. points lower than whites. (Mr. Herrnstein and Mr. Murray mention in passing that "Ashkenazi Jews of European origins . . . test higher than any other ethnic group.") These relative standings have not changed appreciably over time, despite many profound changes during the last half-century in social and economic conditions. The authors acknowledge that an enriched social, educational, economic and intellectual environment can and does raise intelligence scores, but they insist that even when due allowance is made in terms of statistical comparisons of all other factors and measuring their relative weights, intelligence still seems to be strongly influenced by the genes of one's forebears.
This leads to the depressing inference by the authors that no matter how many remedial education programs are brought to bear on intellectually disadvantaged children, many of them will still be hamstrung by an ineradicable cognitive disability created by genetic bad luck.
Society, the authors argue, should accept this as a real possibility and learn to cope with it, rather than merely denouncing all intelligence studies and ignoring the data they yield. For one thing, they say, much of the Government money spent on education programs like Head Start (which was launched in 1964) is wasted, helping only the nation's bloated educational bureaucracies.
"The earliest returns on Head Start were exhilarating," Mr. Herrnstein and Mr. Murray write. "A few months spent by preschoolers in the first summer program seemed to be producing incredible I.Q. gains -- as much as 10 points." The gain was so impressive that in 1966 Congress expanded the program, but by then, the authors of "The Bell Curve" say, "experts were noticing the dreaded 'fade-out,' the gradual convergence in test scores of the children who participated in the program with comparable children who had not. To shorten a long story, every serious attempt to assess the impact of Head Start on intelligence has found fade-out." Cognitive benefits "picked up in the first grade of school are usually gone by the third grade. By sixth grade, they have vanished entirely."
This leaves unanswered questions about whether the declining educational environment after Head Start may in itself account for the fading out of its beneficial effects, and it raises related questions about I.Q. itself: if it can be raised by education, how strongly is it linked to inheritance?
TAKEN individually, none of the propositions advanced in these books is necessarily a call to arms, but in combination they are explosive. The writers themselves, whose views have been widely known (among academics, at least) for many years, are no strangers to public rows, student boycotts, hostile demonstrations and even legal assaults. Aware of the storm of criticism their latest books may face, all four invoke mountains of statistics to fend off anticipated criticism from such critics as Stephen Jay Gould, the Harvard paleontologist who in "The Mismeasure of Man" (1981) charged that "determinist arguments for ranking people according to a single scale of intelligence, no matter how numerically sophisticated, have recorded little more than social prejudice."
The authors cite many surveys suggesting significant correlations between low scores on intelligence tests and undesirable tendencies: a difficulty with learning, a likelihood of remaining impoverished and jobless, an involvement in all types of crime, a tendency not to vote or participate in community affairs, a high incidence of abusing or abandoning children and a record of producing far more children (most of them illegitimate) than can be supported.
Mr. Itzkoff believes that the least intelligent, least educable, poorest, most politically apathetic and abusive contingent of the population is reproducing faster than the smart, rich, politically active and nurturing contingent. He believes this has fueled a dysgenic trend: America's collective smartness is being diluted, gravely endangering the nation's ability to compete economically in international markets; for example, he says, America's declining ability to compete in the global sale of automobiles and other manufactured products, as well as its status as the world's leading debtor nation, are partly the result of the declining cognitive abilities of workers and administrators.
In his book, Mr. Itzkoff places most of the blame for America's alleged intellectual decline on what he sees as an economically and intellectually elite caste of misguided liberals. They have isolated themselves from American society, he says, by their paternalistic treatment of the underclass, by discounting the importance of traditional family values and by failing to raise enough bright, educated children to sustain national competence. Mr. Itzkoff's unabashedly conservative tract condemns liberals in government, in the news media and in society at large, and calls for an end to welfare programs, a radical reform of the academic and employment quota systems that are supported by affirmative action and a tightening of immigration standards, perhaps barring families deemed likely to become permanently dependent on the welfare system.
No such calls to action are urged by Mr. Rushton, the author of "Race, Evolution, and Behavior: A Life History Perspective," or by Mr. Herrnstein and Mr. Murray. Nowhere do they advocate the measures championed by the eugenicists of the 1920's and 1930's, whose ideas were appropriated and perverted by the Nazis as the rationale for the Holocaust. Indeed, the authors of "The Bell Curve" say that the granting to any government or social institution of the power to decide who may breed and who may not is fraught with such obvious dangers as to be unacceptable.
Still, one suspects that the authors of these three books may have softened their agendas somewhat to parry the expected fury of liberal critics, fellow academics and hostile mobs. Given their conclusions about intellect and demographics, it is hard to believe that these writers would oppose a eugenically motivated program designed to influence patterns of reproduction.
They leave many subjects untouched, including the genetic opportunities created by molecular biology -- a Pandora's box loaded with paradoxes and snares. For the first time in human history, it may soon be possible to confer resistance to disease upon living organisms and to free people of inherited scourges like sickle-cell anemia and Tay-Sachs disease. Most people would argue that society is justified in fighting physical disease, but what if we were to carry the war against disease a step farther? Is it wrong to regard a hereditary predisposition to lower intelligence as a kind of genetic disease and to find ways to cure it?
Merely asking that question is enough to cause fear and outrage, and these authors, perhaps wisely, elect to leave it alone. Sooner or later, however, society may have to decide whether human beings have the right -- perhaps even the duty -- to strengthen our species' cognitive defenses against an increasingly dangerous global environment. Human beings evolved over the eons to defend themselves against changes in their environment, and things are still changing.
Meanwhile, there are matters of practical policy to consider, such as the merits of affirmative action. Psychometricians generally agree that blacks, on average, have scored lower than whites on intelligence tests and that whites have scored lower than Asians ever since such tests were devised early in this century. But it is often argued that standardized tests cannot measure intelligence, and that the tests administered in the United States are especially pointless because they are culturally biased against blacks and Hispanics. In 1971 the Supreme Court endorsed such criticisms and ruled that tests of general intelligence (as opposed to tests that solely measure fitness for particular jobs) are discriminatory and cannot be administered as a condition of employment.
Mr. Murray and Mr. Herrnstein argue, however, that charges of systematic bias in intelligence testing are refuted by objective analyses of the available data. They cite the Scholastic Aptitude Test as one of their examples. "If the S.A.T. is biased against blacks," they say, "it will underpredict their college performance." But "external evidence of bias has been sought in hundreds of studies," Mr. Herrnstein and Mr. Murray say. "It has been evaluated relative to performance in elementary school, in secondary school, in the university, in the armed forces, in unskilled and skilled jobs, in the professions. Overwhelmingly, the evidence is that the major standardized tests used to help make school and job decisions do not underpredict black performance, nor does the expert community find any other general or systematic difference in the predictive accuracy of tests for blacks and whites."
One of the strengths of "The Bell Curve" is that it devotes an entire section to the relationships between I.Q. and behavior among whites alone, thereby eliminating the complications arising from interracial comparisons. Analyses of data gathered from exclusively white demographic groups strongly suggest that even if one ignores race, socioeconomic status and family background, I.Q. does indeed correlate with birth rates, crime rates and many other things. Taken as a whole, the statistics are impressive; it seems hard to challenge the notion that I.Q. plays a statistically important role in the shaping of society.
Mr. Murray and Mr. Herrnstein draw extensively from the National Longitudinal Survey of Youth, which has focused on 12,686 high school students, picked as a representative sample of the high school population, who graduated between 1980 and 1982. These students, who were tested and measured at the outset of the study in 1979, have been tracked ever since. Based on the psychometric indicators and the personal histories of these young people, the authors found various suggestive correlations and concluded that the biggest influence on the lives of the people in their sample was the "g" factor -- psychometricians' jargon for core intelligence.
Definitions of intelligence have always been controversial, as have been tests devised to measure it quantitatively. In 1904, the British psychometrician Charles Spearman conceived of a quality he called "g," or "general factor" of intelligence, which has remained part of the psychometrician's lexicon ever since. Spearman's idea was based on his finding that people tend to achieve similar scores on tests that may be very different in content but that contain questions requiring cognitive skill. Such questions were said to measure "g," and tests that emphasized this factor rather than calling for demonstrations of learned skills are said to be "g-loaded" tests.
"G-loaded" tests, the authors of these three books contend, are better predictors of job performance than tests for specific learned skills.
THE Pentagon found the National Longitudinal Survey so useful that its experts used it in devising a general intelligence test known as the Armed Forces Qualification Test, which focuses on problem-solving aptitude and has been administered to all would-be recruits for many years. Mr. Herrnstein and Mr. Murray cite military statistics showing that the "strongly g-loaded" Armed Forces Qualification Test is an excellent predictor of success in military training schools, even including combat schools that stress physical performance. The statistics were assembled from the records of 472,539 service personnel and 828 military schools.
Statistics are so important to the subjects under discussion that Mr. Murray and Mr. Herrnstein offer readers a short course on the interpretation of standard deviations, regression analysis and kindred matters. Their title, "The Bell Curve," refers to the shape of normal distribution graphs -- bulging in the middle and thinning out at the edges -- that are used to represent large numbers of individuals sorted according to any shared characteristic -- weight, exposure to asbestos, taste in clothes or I.Q.
The authors frequently refer to bell curves to make a point: that predictions about any individual based exclusively on his or her I.Q. are virtually useless. It is only when weak correlations between intelligence and job success are applied to large groups of people that they have predictive value. Within statistically large groups of people, the authors say, the pervasive influence of I.Q. on human society becomes evident.
Statistics can be powerfully persuasive but they are as slippery as eels, often susceptible to opposing interpretations. In brief, it is sometimes difficult to tell good statistics from bad ones. Epidemiology, a branch of medicine that relies heavily on statistics and has had some brilliant successes but also some spectacular failures, is a case in point. Epidemiologists have successfully used statistical correlations to convince most people that smoking increases the incidence of certain diseases, for example, but when some epidemiologists pointed out a relationship between low doses of microwave radiation and disease, their claims were bitterly contested. Debates over the epidemiology of intelligence have fallen into the same witch's brew.
ONE of the main problems in assessing statistics is the risk of overlooking confounding variables. A graph demonstrating a positive correlation between intelligence test scores and academic achievement may be very persuasive until, perhaps, one looks at an equally impressive graph that shows a negative correlation between academic achievement and the level of environmental lead to which a student is exposed. Does the lead impair the learning process directly, or does it do so indirectly by reducing cognitive ability? Is it merely a coincidence that environmental lead levels are high in inner-city neighborhoods whose children do badly in school? In any study of I.Q., can an epidemiologist "control" for all the independent factors that may create spurious correlations, such as inequalities in schooling, nutrition, family environment and general health? Maybe so, but it is notoriously difficult for scientists who study intelligence to reach consensus about anything.
Despite its impressive (albeit numbing) mass of statistical arguments, "The Bell Curve" suffers from a consistent weakness: Its authors seem unsure whether they are addressing ordinary (but scientifically literate) readers or professional scholars. In their indecision, they offer either too little or too much information. Their book abounds with tables and graphs, but to gauge the validity of many of the inferences the authors present, a reader is often obliged to dig into the book's huge bibliography and seek out the original papers to which it refers, many of them available only at scientific libraries.
The book leaves unanswered questions a reader might have about such vital matters as sampling procedures. In a discussion of one of the statistical methods for gauging heritability, the authors write: "Nonspecialists need not concern themselves with nuts and bolts, but they may need to be reassured on a few basic points." What follows is partly a discussion of statistical analysis and partly a plea to the reader to accept certain inferences on faith.
Nevertheless, "The Bell Curve" makes a strong case that America's population is becoming dangerously polarized between a smart, rich, educated elite and a population of unintelligent, poor and uneducated people. The authors deplore this polarization, which, they feel, has begun to manifest itself in the polarization of the nation's services: while the elite use private delivery services, go to private schools, live in gated communities and rely on arbitration by private lawyers to handle business disputes, the rest of the population uses the Federal postal service, goes to public schools, lives outside the gates of private communities and relies on public judicial process. Moreover, the authors note, America no longer has a conscript army -- an institution which, with all its faults, was one of the great mixers of young men from all levels of society.
As the job market for the masses -- the people at the low end of the intelligence spectrum -- dries up, Mr. Herrnstein and Mr. Murray write, America's leaders are increasingly likely to create a "custodial" state that minimally nourishes, houses and cares for its despised underclass in the equivalent of an Indian reservation. The result, the authors contend, will be alienation and vicious racial hatred. Once a major segment of society becomes a permanent ward of the state, democracy must swiftly die.
Mr. Rushton's book, "Race, Evolution, and Behavior," is incendiary. His thesis is that separate races of human beings evolved different reproductive strategies to cope with different environments, and that these strategies led to physical differences between races, including differences in brain size and hence in intelligence. Human beings who evolved in the warm but highly unpredictable environment of Africa adopted a strategy of high reproduction, while human beings who migrated to the hostile cold of Europe and northern Asia took to producing fewer children but nurturing them more carefully.
This, Mr. Rushton contends, gave rise to three major races (he scorns the phrase "ethnic groups") -- mongoloids, caucasoids and negroids -- and to physiological differences between the races (things like pelvis size, genital size and fertility rates) that are consonant with their rates of reproduction. He cites worldwide studies concluding that black women ovulate more often than white women, have more twins than white women, mature sexually faster than whites, and differ in other ways that affect their reproduction rates and strategies for child rearing. Among Mr. Rushton's conclusions are that whites, on average, emphasize nurture rather than numbers of offspring, while blacks, on average, are shaped by evolutionary selection pressures to produce more children but to nurture each one less. At the other extreme, some studies suggest that mongoloids evolved to produce even fewer offspring. One indicator, Mr. Rushton says, is a tendency to produce fraternal twins -- twins conceived from two eggs in the same menstrual cycle. The rate of fraternal twins per 1,000 births for mongoloids is less than 4, for whites, approximately 8, and for negroids, more than 16, he says.
THIS is the kind of proposition that makes Mr. Rushton a constant target of furious protests. His classes in psychology at the University of Western Ontario have been barred by hostile demonstrators year after year, forcing him to lecture by videotape.
Mr. Rushton is nevertheless regarded by many of his colleagues as a scholar and not a bigot. The University of Western Ontario has consistently upheld his right to continue teaching. One of his papers on racial differences was presented at a 1989 meeting of the American Association for the Advancement of Science and caused an uproar, but demands to suppress the paper were rejected by Walter Massey, who at the time was president of the association. Mr. Massey, who is black, argued that no scientific organization has the right to act as a censor of scientific debate.
In their book, Mr. Murray and Mr. Herrnstein do not support Mr. Rushton's theories of human evolution, but they comment that "Rushton's work is not that of a crackpot or a bigot, as many of his critics are given to charging. . . . As science, there is nothing wrong with Rushton's work in principle; we expect that time will tell whether it is right or wrong in fact."
The most insistent plea of the four authors is for freedom of debate and an end to the shroud of censorship imposed upon scientists and scholars by pressure groups and an acquiescing society. Mr. Murray and Mr. Herrnstein write that "for the last 30 years, the concept of intelligence has been a pariah in the world of ideas," and that the time has come to rehabilitate rational discourse on the subject. It is hard to imagine a democratic society doing otherwise.
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