The Mismeasure of Man

2007 Schools Wikipedia Selection. Related subjects: Evolution and reproduction; General Biology

The Mismeasure of Man is a controversial, best-selling 1981 book written by the Harvard paleontologist Stephen Jay Gould ( 1941- 2002). The book is a history and critique of the methods and motivations underlying biological determinism, the belief that "the social and economic differences between human groups—primarily races, classes, and sexes—arise from inherited, inborn distinctions and that society, in this sense, is an accurate reflection of biology."

The book also attempts to critique the principal theme of biological determinism, that "worth can be assigned to individuals and groups by measuring intelligence as a single quantity." Gould discusses two prominent techniques used to measure such a quantity, craniometry and psychological testing. According to Gould these methods suffer from "two deep fallacies." The first fallacy is of reification, that is, "our tendency to convert abstract concepts into entities." These entities include IQ (the intelligence quotient) and g (the general intelligence factor), which have been the cornerstone of much intelligence research. The second fallacy is one of ranking, or our "propensity for ordering complex variation as a gradual ascending scale."

The Mismeasure of Man skeptically investigates "the abstraction of intelligence as a single entity, its location within the brain, its quantification as one number for each individual, and the use of these numbers to rank people in a single series of worthiness, invariably to find that oppressed and disadvantaged groups—races, classes, or sexes—are innately inferior and deserve their status."

The book's second edition ( 1996) has been revised and challenges the arguments of Richard Herrnstein and Charles Murray's The Bell Curve, which has also generated much controversy.

Summary of contents

Historical bias in biological sociology

The first parts of the book are devoted to a critical analysis of early works on a supposed biologically inherited basis for intelligence, such as craniometry, the measurement of skull volume and its relation to intellectual faculties. Gould argues that much of this research was based more on prejudice than scientific rigor, demonstrating how in several occasions researchers such as Samuel George Morton, Louis Agassiz, and Paul Broca committed the fallacy of using their expected conclusions as part of their reasoning. The book contains a complete re-working of original data for one of these studies, showing that the original results were based on biases and manipulations, mostly by selection of data. When these biases are accounted for, the original hypothesis—an ordering in skull size ranging from Blacks through Mongols to Whites—is not supported in any way by the data.

Claims of bias and falsification

The following chapters present a historical evaluation of the concept of IQ and of the g factor, which are measures of intelligence used by psychologists. Gould argues that most race-related psychological studies have been heavily biased by the belief that human behaviour is best explained by heredity. Gould notes that the often cited twin studies by Cyril Burt on the genetic heritability of intelligence used falsified data. According to L. S. Hearnshaw (1979), fraud had also been found in Burt's studies in kinship correlations in IQ, and declining levels of intelligence in Britain. Burt had also attempted to declare himself the father of "factor analysis," rather than his predecessor and mentor Charles Spearman (who invented the technique in 1904).

Statistical correlation and heritability

Gould devotes a large part of the book to an analysis of statistical correlation, which is used by psychologists to assert the validity of IQ tests and the heritability of intelligence. For example, to claim that an IQ test measures General intelligence factor relies on the fact that the answers to various questions correlate highly, the heritability of g requires that the scores of respondents who are closely related exhibit higher correlation than those of distant relations. To criticise such claims Gould points out that correlation is not the same as cause. As he puts it, measures of the changes, over time, in "my age, the population of Mexico, the price of Swiss cheese, my pet turtle's weight, and the average distance between galaxies" have a high positive correlation, but that does not mean that Stephen Jay Gould's age goes up because the population of Mexico goes up. Second, and more specifically, a high positive correlation between parent and child IQ can be taken as either evidence that IQ is genetically inherited or that IQ is inherited through social and environmental factors. Since the same data can be used to argue either side of the case, the data in and of itself is not useful.

Furthermore, Gould argues that even if it were demonstrated that IQ is highly genetically heritable within a group, this tells nothing about the causes of IQ differences between groups or whether those differences can be changed by environment. Gould gives the example of height, which is known to be determined mostly through genes within socioeconomic groups, but group differences in height may be due to nutrition as well as genes. Richard Lewontin, a colleague of Gould's, is well-known for emphasizing this argument as it pertains to IQ testing.

According to Gould, a good example of the confusion of heritability is found in the statement “If all environments were to become equal for everyone, heritability would rise to 100% because all remaining differences in IQ would necessarily be genetic in origin.” He says that this claim is at best misleading and at worst, false. First, it is very hard to conceive of a world in which everyone grows up in the exact same environment; the very fact that people are spatially and temporally dispersed means that no one can be in exactly the same environment, for example, a husband and wife may share a house, but they do not live in identical environments because each is married to a different person. Second, even if people grew up in exactly the same environment, not all differences would be genetic in origin. This is because embryonic development involves chance molecular events and random cellular movements that alter the effects of genes.

Gould argues that heritability is not a measure of phenotypic differences between groups, but rather differences between genotype and phenotype within a population. Even within a group, if all members of the group grow up in exactly the same environment, it does not mean that heritability is 100%. All Americans (or New Yorkers, or upper-class New Yorkers – one may define the population in question as narrowly as one likes) may eat exactly the same food, but their adult height will still be a result of both genetics and nutrition. In short, heritability is almost never 100%, and heritability tells us nothing about genetic differences between groups. This is true for height, which has a high degree of heritability; it is all the more true for intelligence. This is true for other reasons besides ones involving heritability, as Gould goes on to discuss.

Gould's most profound criticism is his rejection of the very thing that IQ is meant to measure, "general intelligence" (or g). IQ tests, he points out, ask many different kinds of questions. Responses to different kinds of questions tend to form clusters. In other words, different kinds of questions can be given different scores – which suggests that an IQ test is really a combination of a number of different tests that test a number of different things. Gould claims that proponents of IQ tests assume that there is such a thing as general intelligence, and analyze the data so as to produce one number, which they then claim is a measure of general intelligence. Gould argues that this one number (and therefore, the implication that there is a real thing called "general intelligence" that this number measures) is in fact an artifact of the statistical operations psychologists apply to the raw data. He argues that one can analyze the same data more effectively and end up with a number of different scores (that are as or more valid, meaning they measure something) rather than one score.

Finally, Gould points out that he is not opposed to the notion of "biological variability" which is the premise that heredity influences intelligence. Instead, he does criticize the notion of "biological determinism" which is the idea that genes determine destiny and there is nothing we can or should do about this.



  • 1981 – National Book Critics Circle Award for nonfiction
  • 1983 – Outstanding Book Award from the American Educational Research Association
  • 1991 – Iglesias Prize (Italian translation)


"When published in 1981, The Mismeasure of Man was immediately hailed as a masterwork, the ringing answer to those who would classify people, rank them according to their supposed genetic gifts and limits. And yet the idea of innate limits—of biology as destiny—dies hard, as witness the attention devoted to The Bell Curve, whose arguments are here so effectively anticipated and thoroughly undermined by Stephen Jay Gould. In this [2nd] edition Dr. Gould traces the subsequent history of the controversy on innateness right through The Bell Curve. Further, he has added five essays, in a separate section at the end, on questions of The Bell Curve in particular and on race, racism, and biological determinism in general. These additions strengthen the claim of this book to be 'a major contribution toward deflating pseudobiological "explanations' of our present social woes.'"
  • Christopher Lehmann-Haupt, "Books Of The Times" The New York Times, Section C; Page 29.
"He confronts a basic tool of the measurers—the statistical technique called factor analysis, developed by the influential English psychologist Charles Spearman—and demonstrates persuasively how factor analysis led to the cardinal error in reasoning of confusing correlation with cause, or, to put it another way, of attributing false concreteness to the abstract. It is this sort of performance that makes the book's eventual refutation of Arthur Jensen seem incidental, for it is far more absorbing to have our powers of reason challenged than it is to have our social consciences shaken."
  • Saturday Review, London.
"A rare book—at once of great importance and wonderful to read. . . . Gould presents a fascinating historical study of scientific racism, tracing it through monogeny and polygeny, phrenology, recapitulation, and hereditarian IQ theory. He stops at each point to illustrate both the logical inconsistencies of the theories and the prejudicially motivated, albeit unintentional, misuse of data in each case. . . . A major addition to the scientific literature."
  • Sunday Times, London.
"The great merit of Stephen Gould's account of the disastrous history of phychometrics is that he shifts the argument from a sterile contest between environmentalists and hereditarians and turns it into an argument between those who are impressed with what our biology stops us doing and those who are impressed with what it allows us to do."
  • Monthly Review, Richard York and Brett Clark.
"The power of Gould's analysis lies in his focus on particulars. Rather than attempt a grand critique of all 'scientific' efforts aimed at justifying social inequalities, Gould performs a well-reasoned assessment of the errors underlying a specific set of theories and empirical claims."


The Mismeasure of Man has been highly controversial. The popular and literary press have mostly praised the book, while most scientific journals have been critical. Among psychologists, the reaction has been largely negative. Hans Eysenck's review called the book "a paleontologist's distorted view of what psychologists think, untutored in even the most elementary facts of the science."

Critics have accused Gould of selective reporting, distorting the viewpoints of scientists, and letting his viewpoints be influenced by political and ethical biases, and allege that many of Gould's claims about the validity of intelligence measures, such as IQ, contradict mainstream psychology.

  • Bernard Davis ( 1916– 1994), former professor at the Harvard Medical School, and former head of the Centre for Human Genetics, indicates that "While the nonscientific reviews of The Mismeasure of Man were almost uniformly laudatory, the reviews in the scientific journals were almost all highly critical." Davis describes the book as "a sophisticated piece of political propaganda, rather than as a balanced scientific analysis." On Gould's use of biological determinism and his understanding of intelligence testing, Davis states "Gould would prefer to combat the straw man of naive, 'pure' determinism, he fails to note that the science of genetics has altogether replaced this concept with interactionism."

On Gould's use of the concept of " reification" Davis adds:

"Gould's argument on reification purports to get at the philosophical foundation of the field. He claims that general intelligence, defined as the factor common to different cognitive abilities, is merely a mathematical abstraction; hence if we consider it a measurable attribute we are reifying it, falsely converting an abstraction into an 'entity' or a 'thing'—variously referred to as 'a hard, quantifiable thing,' 'a quantifiable fundamental particle,' 'a thing in the most direct, material sense.' Here he has dug himself a deep hole. . . . Indeed, this whole argument is fantastic. The scientist does not measure 'material things': He measures properties (such as length or mass), sometimes of a single 'thing' (however defined), and sometimes of an organized collection of things, such as a machine, a biological organ, or an organism. In a particularly complex collection, the brain, some properties (i.e., specific functions) have been traced to narrowly-localized regions (such as the sensory or motor nuclei connected to particular parts of the body)"

On Gould's "highly selective" use of data, he adds:

"His historical account is highly selective; he asserts the non-objectivity of science so that he can test for scientific truth, flagrantly, by the standards of his own social and political convictions; and by linking his critique to the quest for fairness and justice, he exploits the generous instincts of his readers. . . . In effect, we see here Lysenkoism risen again: an effort to outlaw a field of science because it conflicts with a political dogma.

Davis also points out possible political motivations behind Gould's attacks

"A left-wing group called Science for the People, of which Gould is a member, has been particularly active in campaigning against such studies. Instead of focusing, in the earlier tradition of radical groups, on defects in our political and economic system that demand radical change, this group has aimed at politicizing science, attacking in particular any aspect of genetics that may have social implications. Their targets have included genetic engineering, research on the effects of an XYY set of chromosomes, sociobiology, and efforts to measure the heritability of intelligence. Several years ago Gould co-signed their intemperate attack on E.O. Wilson's Sociobiology: The New Synthesis. Now, in The Mismeasure of Man, he has extended the attack to cognitive psychology and educational testing, because they may reveal genetic differences."

Davis adds

"Gould is entitled, of course, to whatever political views he wishes. But the reader is also entitled to be aware of his agenda."
  • David J. Bartholomew, Emeritus Professor of Statistics, London School of Economics, and former president of the Royal Statistical Society, states in his book Measuring Intelligence, Facts and Fallacies, (University Press, Cambridge, 2004) that Gould erred in his use of factor analysis. Bartholomew asks
"...[w]here did Gould go wrong? First, by failing to distinguish between an empirical index constructed from a set of scores, like a principal component, on the one hand, and an underlying (latent) variable which can never be observed, but which we can learn something about with the aid of a model, on the other. ... Secondly, by ignoring the fact that we are dealing with samples – of subjects and items – and that this has implications for the inferences we can make."
"Gould’s treatment of factor analysis also devotes a great deal of attention to something called rotation. It is on the alleged fact that rotation can apparently make factors come and go that Gould bases his most damaging attack. Here too lies another flaw, this time of interpretation ..." (p. 73)

When addressing Gould's main points Bartholomew adds that Gould's

"...charge of reification is, therefore, irrelevant to the main issue. What matters is whether or not a reasonably stable value can be ascertained for any individual which has predictive value. This is the case with IQ and also for g. Within their limits IQ and g are real in the pragmatic sense that they have predictive or explanatory value." (p. 145)

Bartholomew continues that on the issue of whether intelligence is innate and reflected in the general intelligence factor, or g, is

"...well supported by the empirical evidence. If, as we have conjectured, this quality is also a reflection of the structure/functioning of the fully developed brain, g could be said to be innate in much the same way as eye colour or exceptional musical talent. A final judgement on this claim must await further research on the biological basis of intelligence but present indications do not support Gould." (p. 146)

And Bartholomew adds that

"it is almost certainly true that there is a heritable component in intelligence"... with "the figure anywhere between 40 and 80 per cent." Bartholomew concludes on this issue that "most of the current empirical evidence is strongly against Gould." (p 146)
  • Charles Murray in an interview in Skeptic magazine, claimed that Gould misrepresented his views.
  • Arthur Jensen, a prominent educational psychologist, in a paper titled The Debunking of Scientific Fossils and Straw Persons. made the following observation:
Stephen Jay Gould is a paleontologist at Harvard's Museum of Comparative Zoology and offers a course at Harvard entitled, "Biology as a Social Weapon." Apparently the course covers much the same content as does the present book. Having had some personal cause for interest in ideologically motivated attacks on biologically oriented behavioural scientists, I first took notice of Gould when he played a prominent role in a group called Science for the People and in that group's attack on the theories of Harvard zoologist Edward O. Wilson, a leader in the development of sociobiology. . .

Jensen also makes a complaint similar to Murray's when charging Gould with misrepresentations.

In his references to my own work, Gould includes at least nine citations that involve more than just an expression of Gould's opinion; in these citations Gould purportedly paraphrases my views. Yet in eight of the nine cases, Gould's representation of these views is false, misleading, or grossly caricatured. Nonspecialists could have no way of knowing any of this without reading the cited sources. While an author can occasionally make an inadvertent mistake in paraphrasing another, it appears Gould's paraphrases are consistently slanted to serve his own message.

Arthur Jensen, like Davis, suggested that Gould relies on information that is outdated while ignoring present research and information that does not support his conclusions.

Of all the book's references, a full 27 percent precede 1900. Another 44 percent fall between 1900 and 1950 (60 percent of those are before 1925); and only 29 percent are more recent than 1950. From the total literature spanning more than a century, the few "bad apples" have been hand-picked most aptly to serve Gould's purpose.

However this sampling may only reflect Gould's historical treatment of the subject, and his literary style of incorporating historical thinkers—such as Plato, Alexander Pope, Thomas Jefferson, and his profession's hero Charles Darwin—into his narrative. Percentages aside, Gould argued that he had "focused upon the leading and most influential scientists of their times and have analyzed their major works." (1981, p. 27)

In an article written for the April 1982 edition of Nature, Steve Blinkhorn, a Senior Lecturer in Psychology at Hatfield Polytechnic begins his criticism of Gould's work thus

"With a glittering prose style and as honestly held a set of prejudices as you could hope to meet in a day's crusading, S.J. Gould presents his attempt at identifying the fatal flaw in the theory and measurement of intelligence."

And adds the following criticism of Gould's attempt to mislead the lay public through the "careful selection, emphasis and juxaposition" of facts

"It is a masterpiece of propaganda, researched in the service of a point of view rather than written from a fund of knowledge. For the best propaganda requires not the suppression or distortion of facts but their careful selection, emphasis and juxtaposition. So, in a work which declares its concern to be with the notion of intelligence as a single measurable "thing" in the head, we find that two-thirds of the argument is given over to a careful reworking of early attempts to establish craniometric and anthropometric criteria of intelligence, and an admirably disturbing account of the Gadarene rush to press IQ tests into the service of social engineering in the USA in the first half of this century. As Gould rightly emphasizes, many of the uses to which tests were put made mockery of their original purpose."
"The final third of the book is the attempt proper to debunk the notion of general intelligence as arising specifically in the school of factor analysts starting with Spearman. But by this stage the reader has been presented with sufficient examples, sufficiently carefully examined, of racial and social prejudice in the work of scientists, of distorted data, fudged analysis and twisted interpretation as to the inexpert might establish a necessary connection. Add to that the soft target of Cyril Burt, some rather inaccurate observations on the role and effects of the 11+ examination system in Britain and a remarkably detailed account of antique methods of factor analysis, and you have all the makings of a lively, plausible, opinionated and zesty potboiler."
  • J. Philippe Rushton, head of the Pioneer Fund, which funds research towards "the scientific study of heredity and human differences," accused Gould of "scholarly malfeasance" for misrepresenting or ignoring relevant scientific research, and attacking dead arguments and methods. Rushton also charges that Gould fails to mention recent discoveries made from Magnetic Resonance Imaging (MRI) which show a 0.4 correlation between brain-size and IQ
  • Hans Eysenck—who at the time of his death was the most frequently cited living psychologist—wrote that: "Gould is one of a number of politically motivated scientists who have consistently misled the public about what psychologists are doing in the field of intelligence, what they have discovered and what conclusions they have come to. Gould simply refuses to mention unquestionable facts that do not fit into his politically correct version; he shamelessly attacks the reputations of eminent scientists of whom he disapproves, on completely nonfactual grounds, and he misrepresents the views of scientists."

Some nonspecialists have also been critical of Gould's methods. Steve Sailer, in his article for the publication National Review, concludes

"Gould's most famous and influential book was The Mismeasure of Man, which exemplified his trademark combination of antiquarianism and guilt by association in the service of character assassination. In it, he attempted to destroy the modern science of IQ by recounting the stumblings of 19th-century researchers working before the IQ test was even invented. Of course, that line of attack makes as much sense as trying to discredit modern astronomy by writing a book revealing that ancient astronomers thought the sun went around the Earth."
  • Finally, many of Gould's positions conflict with conclusions reached by the American Psychological Association, whose Board of Scientific Affairs has published a report finding that IQ scores do in fact have high predictive validity for certain individual differences.
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