Since its publication late last year, The Bell Curve by Charles Murray and the late Richard Herrnstein has encountered a barrage of criticism for emphasizing the societal implications of IQ differences. Some critics argue that the work rests upon “bogus” and “outdated” theories of intelligence. Others charge that the book promotes dubious scientific claims. One columnist has described the 850-page text as “racist drivel.” Still other critics acknowledge its research findings yet dismiss the book as “politics disguised as science.”

In the wake of this criticism, several fallacies about intelligence have surfaced in the media. These falsehoods play a pivotal role in the controversy that surrounds IQ research, and public reaction to The Bell Curve indicates the extent to which these fallacies dominate public opinion. Consider the responses from Newsweek readers to its October 24 cover story, “IQ: Is It Destiny?” Nearly one-third of 450 letters to the editor deplored the magazine’s coverage of the issue.

Reactions to the book center on three general myths about IQ: that there is no such thing as general intelligence, that IQ tests are worthless, and that genetics is insignificant when it comes to individual or group differences in intelligence. The source of these fallacies is the ideology of egalitarianism, not scientific precedent. Briefly, here is a closer look at these popular myths.

The first is the idea that “IQ” (general intelligence) is a discredited and scientifically invalid concept. William Raspberry, columnist for the Washington Post, argues this very point. He claims that Murray “has embraced . . . largely discredited views regarding the heritability, measurability and immutability of intelligence.” What Raspberry means by this is not exactly clear, since he fails to explain why these concepts are invalid.

The lack of unanimity among experts does not mean that these ideas have been “discredited.” hi fact, the opposite appears to be true. The Snyderman and Rothman survey of experts from 1988 shows more agreement than disagreement over “heritability” and “measurability.” The importance of measuring intelligence is also summarized by Morton Hunt in The Story of Psychology: “Whatever one calls them, and whatever one’s stance on intelligence testing, the fact remains that mental measurement is useful, is beneficial to society . . . and remains one of psychology’s major contributions to modern life in America and most other developed nations.”

Another fallacy is that the influence of genetics on IQ is trivial and ambiguous. Critics like E.J. Dionne of the Washington Post question the scientific accuracy of “heritability estimates” of IQ. Dionne argues that such generalizations arc unscientific because the “science of the matter is utterly crude.” Initially, Darwin’s theory of natural selection and Newtonian physics were just as “crude.” The fact that heritability estimates are “crude” makes them neither insignificant nor unscientific.

The most reliable data from twin and adoption studies show that the range of genetic influence extends from nearly half (40 percent) to slightly more than three quarters (80 percent). Behavior geneticist Thomas J. Bouchard, director of the Minnesota Study of Twins, notes that “the evidence regarding genetic influence on intelligence, when viewed as a whole, overwhelmingly supports the conclusion that genetic factors are the single most important source of variation.”

A third fallacy is that alternative theories of intelligence, notably Howard Gardner’s concept of multiple intelligences (MI), refute the traditional notion of general intelligence (psychometric “g”). Gardner’s research is often considered to be proof that a general factor of intelligence, or simply “g,” is scientifically discredited. In fact, most experts on intelligence do not favor Gardners MI theory. The consensus from a 1992 Dahlem workshop on behavior genetics shows that leading researchers accept “g” as a valid assessment of intelligence:

Despite many twentieth-century efforts to identify independent dimensions of intellectual variation (e.g., by Thurstone, Guilford, Hudson, Gardner), g-factors continue to account for some 50 percent of the variance in matrices of correlations between abilities. Beyond g, other independent dimensions each typically account for less than 10 percent of the variance of abilities. From this perspective, g may be to cognitive psychology what carbon is to organic chemistry.

The Snyderman and Rothman survey also reveals that, among experts, “58 percent favor some form of a general intelligence solution, while 13 percent feel separate faculties are a superior description. Only 16 percent think the data are sufficiently ambiguous as not to favor either solution. Nonresponse rate was 15 percent.”

One of the most exhaustive studies of human intelligence, John B. Carroll’s Human Cognitive Abilities, reiterates the importance of general intelligence. Based on more than 60 years of research, his work reanalyzes 477 data sets compiled since the early days of IQ testing. Although Carroll recognizes a number of specialized abilities, he concludes that the evidence of a general factor among these cognitive abilities is indisputable.

Another widespread fallacy is that individual and ethnic differences in IQ are simply the result of socioeconomic conditions, which brings us to the most scrutinized parts of The Bell Curve: the two chapters and one appendix that explore race differences in mental ability. Herrnstein and Murray take a biosocial approach to this explosive issue, which is to say that while they affirm the role of environment, they also recognize the probable influence of genetics. While many critics question the work of researchers who explore genetic links to race differences—most notably studies by Arthur Jensen, Richard Lynn, and J. Philippe Rushton—few bother to point out that these three scholars lead highly respected careers within their own professions.

Contrary to recent allegations, Herrnstein and Murray examine the complex issue of ethnic differences with great care. Simply put, they conclude that the underlying sources of these differences remain obscure. By reviewing Jensen’s “Spearman hypothesis” and Rushton’s “differential K theory,” they point to the plausibility of a genetic basis for race differences in IQ. Both Herrnstein and Murray believe that these theories remain to be proven, but doubt that racial disparities are strictly the result of racism, poverty, or oppression.

In a recent issue of the Nation, Northwestern University professor Adolph Reed, Jr., revives another myth: that Sir Cyril Burt, one of Britain’s most distinguished psychologists, fabricated IQ data. Reed questions Bouchard’s findings on identical twins by claiming that “[Bouchard] has found the same strikingly high correlations in IQ among his sample of supposedly real twins raised apart that Sir Cyril Burt found among the imaginary twins in his fraudulent ‘research.'” If taken at face value, Reed’s assertion disregards recent major developments in the Burt case. This episode illustrates why the crusade against IQ research is ideologically driven.

Perhaps Britain’s most distinguished psychologist, Burt was accused of faking twin data a few years after his death in 1972. Since then, the incident has received an endless amount of media coverage. Two years ago, Omni magazine identified Burt as one of the top ten frauds in history. But this is only part of the story. A few years ago, two meticulously thorough studies by two British scholars found that the allegations against Burt were groundless and politically motivated. In separate published accounts, both authors concluded that the evidence was too flimsy to substantiate the charges against Burt. Even though these findings discredit Burt’s detractors, the accusations continue to surface in the media as if they were irrefutably proven.

Few scholarly works have encountered the hostile scrutiny that has confronted The Bell Curve. Each sentence of every chapter as well as hundreds of endnotes, bibliographic entries, and even acknowledgments have been scoured for “tainted sources.” The bulk of this criticism comes from egalitarian ideologues who refuse to accept any evidence showing that innate differences in mental ability contribute to human inequality.

As Michael Levin, professor of philosophy at City College of New York, points out, “You cannot loathe a man’s advice because his motives are despicable, and despise his motives because his advice is loathsome.” Indeed, if critics of The Bell Curve expect to be taken seriously, they will abandon the sophistry and ad hominem assaults that are incapable of refuting the book’s principal arguments.