The Mismeasure of Man

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The Mismeasure of Man is a 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 critiques 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 had 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 Morton's original data of endocranial volume, asserting that the original results were based on biases and manipulations, both by the selection of data and by Morton physically manipulating his results. While Gould never actually examined Morton's skull collection himself, subsequent investigations found Morton's original data to be more accurate than Gould describes. Gould claims however that when these purported 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. J. Michael conducted the same experiments and found that Gould had exaggerated some of his conclusions. However, there were some discrepancies in Morton's calculations as well. As of now, there are no definitive answers. This issue remains to be resolved and is one of the most contested portions of the book.

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 those involving heritability, as Gould goes on to discuss.

Gould also rejects 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.

Reception

The Mismeasure of Man has won several awards, including the National Book Critics Circle Award for non-fiction in 1981 and the Outstanding Book Award from the American Educational Research Association in 1983. An Italian translation won the Iglesias Prize in 1991.

Praise

Leon J. Kamin, an American psychologist at Princeton University, writes that Gould's work "effectively anticipated and thoroughly undermined" the arguments later presented in The Bell Curve. He praises the additions to the book's 1996 edition, writing that they "strengthen the claim of this book to be 'a major contribution toward deflating pseudo biological "explanations" of our present social woes.'"

Christopher Lehmann-Haupt stresses Gould's critique of factor analysis, saying the book "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." He considers the critique more important than Gould's attempts to refute psychologists such as Arthur Jensen, "for it is far more absorbing to have our powers of reason challenged than it is to have our social consciences shaken."

The Saturday Review, a British journal, praises the book as a "fascinating historical study of scientific racism" that "illustrate[s] both the logical inconsistencies of the theories and the prejudicially motivated, albeit unintentional, misuse of data in each case."

A review in the Sunday Times, another British publication, speaks favorably of the book, suggesting Gould "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."

Richard York and Brett Clark of the US Monthly Review praise Gould's narrow focus: "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."

Criticisms

The Mismeasure of Man has been highly controversial in some quarters, particularly among psychologists. The popular and literary press almost universally praised the book, while numerous reviews in technical journals have been critical. This contrast can be misleading, since some reviews in both were authored by professional scientists; for example, Richard Lewontin, well-known for his long-standing support for similar points of view, reviewed the work in The New York Review of Books and was highly enthusiastic.

Initial reviews in scientific journals, such as Science (Samelson, 1982), Nature, and Science '82, tended to be critical on a number of counts. Bernard Davis claimed that a laudatory review by Morrison appeared in Scientific American because that journal's editorial staff had "long seen the study of the genetics of intelligence as a threat to social justice" Among many 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."

Numerous critics have accused Gould of selective reporting, distorting the viewpoints of scientists, and letting his viewpoints be influenced by political and ethical biases; they 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, accuses him of setting up straw man arguments, incorrectly defining key terms (notably " reification"), choosing data in a "highly selective" manner, and in general being motivated more by political concerns than scientific ones. His review can be found here.

• 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 (p. 73) and irrelevantly focusing on the issue of reification and ignoring scientific consensus on the existence of the "g" factor of intelligence (p. 145-46).

• Charles Murray in an interview in Skeptic magazine, claimed that Gould misrepresented his views.

• Arthur Jensen, an educational psychologist, in a paper titled The Debunking of Scientific Fossils and Straw Persons available here, also accused Gould of using straw man arguments, misrepresenting other scientists and operating from a political agenda.

• In an article written for the April 1982 edition of Nature, Steve Blinkhorn, a Senior Lecturer in Psychology at Hatfield Polytechnic, also accuses him of selectively juxtaposing data in order to further a political agenda.

• 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.