Science Literature

One of the few books of Stephen Jay Gould I never read was his Mismeasure of Man. I suppose it was a low priority - as I have never considered cranial capacity a measure of intelligence or state of advancement. This is partly because of an awareness that women tend to have smaller skulls than men and yet this has no bearing on their cognitive skills. I knew that Gould was taking Samuel George Morton to task because Morton had considered cranial capacity to be significant for ranking human races in some sort of hierarchical order. Gould considered that Morton provided a case study of someone who had "finangled" his data and his analysis to reach unwarranted conclusions. His 1978 paper concluded in this way:

"Yet, through all this juggling, I find no indication of fraud or conscious manipulation. Morton made no attempt to cover his tracks, and I must assume that he remained unaware of their existence. He explained everything he did, and published all his raw data. All I discern is an a priori conviction of racial ranking so powerful that it directed his tabulations along pre-established lines. Yet Morton was widely hailed as the objectivist of his age, the man who would rescue American science from the mire of unsupported speculation."

Biological determinism is a minefield for the unwary - and for the mature (source here)

Gould carried the day with his analysis of Morton's work. There were some who questioned his conclusions, but most regarded Gould's paper and book as definitive. It took on an iconic status.

"Gould used Morton as a case study to argue that "unconscious or dimly perceived finagling, doctoring, and massaging are rampant, endemic, and unavoidable in a profession that awards status and power for clean and unambiguous discovery". Gould's analysis of Morton is widely read, frequently cited, and still commonly assigned in university courses. Morton has become a canonical example of scientific misconduct and an oft-told cautionary tale of how human variation is inevitably mismeasured."

The icon has been demolished by Jason Lewis and colleagues, who have remeasured Morton's skulls and revisited the data analysis issues. Their findings have surprised everyone. First, consider the database. Gould did not measure any of the skulls and concentrated his fire on the analysis. However, he did claim that Morton had mismeasured his specimens. To test this, Lewis et al. remeasured 308 of the 670 skulls in Morton's collection. Using their measurements as the standard for comparison, they found that seven of the racial groups were mismeasured by more than 5%. However, they found no correlation of these mismeasurements with Moreton's a priori biases. Therefore, they have concluded that Gould was wrong to make the claims he did about measurement bias. Note these comments from their paper and remember that Gould made no measurements himself to check:

"Gould famously suggested that Morton's measurements may have been subject to bias: "Plausible scenarios are easy to construct. Morton, measuring by seed, picks up a threateningly large black skull, fills it lightly and gives it a few desultory shakes. Next, he takes a distressingly small Caucasian skull, shakes hard, and pushes mightily at the foramen magnum with his thumb. It is easily done, without conscious motivation; expectation is a powerful guide to action"."

Next, Lewis et al. address the analysis of the data. Gould came to the conclusion that there were no differences to speak of among Morton's races and the claimed differences were explained as the misuse of various statistical strategies. The details need not concern us here. Lewis et al. summarise this part of their research as follows: "Our analysis of Gould's claims reveals that most of Gould's criticisms are poorly supported or falsified." Furthermore, they note: "It is doubtful that Morton equated cranial capacity and intelligence, calling into question his motivation for manipulating capacity averages." They conclude that Gould himself provides the better example of developing research to match a personal bias.
"Of the substantive criticisms Gould made of Morton's work, only two are supported here. First, Morton indeed believed in the concept of race and assigned a plethora of different attributes to various groups, often in highly racist fashion. This, however, is readily apparent to anyone reading the opening pages of Morton's Crania Americana. Second, the summary table of Morton's final 1849 catalog has multiple errors. However, had Morton not made those errors his results would have more closely matched his presumed a priori bias. Ironically, Gould's own analysis of Morton is likely the stronger example of a bias influencing results."

Such radical outcomes of this work has raised ripples of astonishment among interested scientists and educators. There are strong words coming from the anthropologist John Hawks' blog:

"Anyway, you can see why I find this outrageous. Gould used the well-documented work of a long-dead man to make an argument that unconscious bias is widespread in science. He posed as a concerned critic, but thereby cast doubt on the validity of the scientific enterprise. He picked volume measurement and tabulation of averages as his target, making it seem as if the simplest and most objective observations - the Junior High-level science methods - were themselves subject to all-encompassing cultural biases. His paper and book are very widely read and cited by people who will never examine the primary evidence. Gould owed us a responsible reading and trustworthy reporting on that evidence. In its place, he made up fictional stories, never directly examined the evidence himself, and misreported Morton's numbers."

The paradox for me is that I regard Gould as having exposed the superficiality of Darwinian "just so" adaptationist stories, yet here he is guilty of the same deed - constructing a just-so story about Morton measuring his skulls. I regarded Gould as injecting some interesting statistical ideas to historical science, and yet here he is, manipulating data to make it conform to an expected outcome. The basic lesson about cultural bias intruding into science is undiminished - but the case study subject is now Stephen Jay Gould, not Samuel George Morton. And if Gould illustrates the problem, questions about the cultural bias of any contemporary scientific writerwriter is legitimate and should be encouraged. John Hawks concludes thus:

"The new paper is open access, and I think that everyone should read it. The text is easy to follow, and the authors include clear answers to common questions about Morton's work and beliefs. It is a very suitable article for assignment in classes. They note that the basic issue here (endocranial volume of different groups) is largely explained by ecogeography - the authors mention climate explicitly, but I would add body size and life history as parameters that covary with climate. Measurement of endocranial volume was cutting edge science in 1840, but I repeat, this is simple stuff."

The Mismeasure of Science: Stephen Jay Gould versus Samuel George Morton on Skulls and Bias
Jason E. Lewis, David DeGusta, Marc R. Meyer, Janet M. Monge, Alan E. Mann, Ralph L. Holloway
PLoS Biology, 9(6): e1001071 | doi:10.1371/journal.pbio.1001071

First paragraph: Stephen Jay Gould, the prominent evolutionary biologist and science historian, argued that "unconscious manipulation of data may be a scientific norm" because "scientists are human beings rooted in cultural contexts, not automatons directed toward external truth", a view now popular in social studies of science. In support of his argument Gould presented the case of Samuel George Morton, a 19th-century physician and physical anthropologist famous for his measurements of human skulls. Morton was considered the objectivist of his era, but Gould reanalyzed Morton's data and in his prize-winning book The Mismeasure of Man argued that Morton skewed his data to fit his preconceptions about human variation. Morton is now viewed as a canonical example of scientific misconduct. But did Morton really fudge his data? Are studies of human variation inevitably biased, as per Gould, or are objective accounts attainable, as Morton attempted? We investigated these questions by remeasuring Morton's skulls and reexamining both Morton's and Gould's analyses. Our results resolve this historical controversy, demonstrating that Morton did not manipulate data to support his preconceptions, contra Gould. In fact, the Morton case provides an example of how the scientific method can shield results from cultural biases.

See also:

Gould, S.J. Morton's Ranking of Races by Cranial Capacity, Science, 5 May 1978, 200, 503-509.

Hawks, J. Gould's "Unconscious Manipulation of Data", John Hawks Weblog (8 June 2011)

Post-script: an Editorial in Nature comments on the research paper and concludes with the paragraph below. Here is another indication that the peer review process as presently practiced is making it more difficult to publish unorthodox or potentially controversial ideas. Can this be good for science?
"Just as important is the readiness of the scientific community to undertake such studies, and to see them through the sometimes difficult publication process. The criticism of Gould was rejected by the journal Current Anthropology, and spent eight months in the review process at PLoS Biology. And although an undergraduate did publish a more modest study scrutinizing Gould in 1988, it is remarkable that it has taken more than 30 years for a research group to check Gould's claims thoroughly. Did Gould's compelling writing and admirable anti-racist motivations help to delay scrutiny of his facts? Quite possibly, and this is regrettable. Although future historians will be happy to scrutinize our most persuasive and celebrated luminaries, today's scientists should not leave the job to them." (Mismeasure for mismeasure, Nature, 474, 419 (23 June 2011)