The case of the shifting black mean
In the Crania Americana, Morton cited 78 cubic inches as the average cranial capacity for blacks. Five years later, in the Crania Aegyptiaca, he appended the following footnote to his table of measurements: “I have in my possession 79 crania of Negroes born in Africa.… Of the whole number, 58 are adult… and give 85 cubic inches for the average size of the brain” (1844, p. 113).
Since Morton had changed his method of measurement from mustard seed to lead shot between 1839 and 1844,1 suspected this alteration as a cause for the rising black mean. Fortunately, Morton remeasured most of his skulls personally, and his various catalogues present tabulations of the same skulls by both seed and shot (see Gould, 1978, for details).
I assumed that measures by seed would be lower. Seeds are light and variable in size, even after sieving. Hence, they do not pack well. By vigorous shaking or pressing of the thumb at the foramen magnum (the hole at the base of a skull), seeds can be made to settle, providing room for more. Measures by seed were very variable; Morton reported differences of several cubic inches for recalibrations of the same skull. He eventually became discouraged, fired his assistants, and redid all his measurements personally, with lead shot. Recalibrations never varied by more than a cubic inch, and we may accept Morton’s judgment that measures by shot were objective, accurate, and repeatable—while earlier measures by seed were highly subjective and erratic.
I then calculated the discrepancies between seed and shot by race. Shot, as I suspected, always yielded higher values than seed. For 111 Indian skulls, measured by both criteria, shot exceeds seed by an average of 2.2 cubic inches. Data are not as reliable for blacks and Caucasians because Morton did not specify individual skulls for these races in the Crania Americana (measured by seed). For Caucasians, ig identifiable skulls yield an average discrepancy of only 1.8 cubic inches for shot over seed. Yet 18 African skulls, remeasured from the sample reported in Crania Americana, produce a mean by shot of 83.44 cubic inches, a rise of 5.4 cubic inches from the 1839 average by seed. In other words, the more “inferior” a race by Morton’s a priori judgment, the greater the discrepancy between a subjective measurement, easily and unconsciously fudged, and an objective measure unaffected by prior prejudice. The discrepancy for blacks, Indians, and Caucasians is 5.4, 2.2, and 1.8 cubic inches, respectively.
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.
Table 2.5 Corrected values for Morton’s final tabulation
PEOPLE CRANIAL CAPACITY (IN3)
Mongolians
87
Modern Caucasians
87
Native Americans
86
Malays
85
Ancient Caucasians
84
Africans
83
The final tabulation of 1849
Morton’s burgeoning collection included 623 skulls when he presented his final tabulation in 1849—an overwhelming affirmation of the ranking that every Anglo-Saxon expected.
The Caucasian subsamples suffer from errors and distortions. The German mean, reported at 90 in the summary, is 88.4 from individual skulls listed in the catalogue; the correct Anglo-American average is 89 (89.14), not 90. The high English mean of 96 is correct, but the small sample is entirely male.* If we follow our procedure of computing averages among subsamples, the six modern Caucasian “families” yield a mean of 87 cubic inches.† The ancient Caucasian average for two subsamples is 84 cubic inches (Table 2.5).
Six Chinese skulls provide Morton with a Mongolian mean of 82, but this low value records two cases of selective amnesia: First, Morton excluded the latest Chinese specimen (skull number 1336 at 98 cubic inches), though it must have been in his collection when he published his summary because he includes many Peruvian skulls with higher numbers. Secondly, although Morton deplored the absence of Eskimos from his collection (1849, p. iv), he did not mention the three Eskimo skulls that he had measured for Crania Americana. (These belonged to his friend George Combe and do not appear in Morton’s final catalogue.)
Morton never remeasured these skulls with shot, but if we apply the Indian correction of a.2 cubic inches to their seed average of 86.8 we obtain a mean of 89. These two samples (Chinese with number 1336 added, and Eskimo conservatively corrected) yield a Mongolian average of 87 cubic inches.
By 1849 Morton’s Indian mean had plummeted to 79. But this figure is invalid for the same reason as before, though now intensified—inequality of numbers among subsamples. Small-headed (and small-statured) Peruvians provided 23 percent of the 1839 sample, but their frequency had risen to nearly half (155 of 338 skulls) by 1849. If we use our previous criterion and compute the average of all subsamples weighted equally, the Indian average is 86 cubic inches.
For the Negro average, we should drop Morton’s australoids because he wanted to assess the status of African blacks and we no longer accept a close relationship between the two groups—dark skin evolved more than once among human groups. I also drop the Hottentot sample of 3. All skulls are female, and Hottentots are very small in stature. Native and American-born blacks, amalgamated to a single sample, yield an average value between 82 and 83, but closer to 83.
In short, my correction of Morton’s conventional ranking reveals no significant differences among races for Morton’s own data (Table 2.5). All groups rank between 83 and 87 cubic inches, and Caucasians share the pinnacle. If western Europeans choose to seek their superiority in high averages for their subsamples (Germanics and Anglo-Saxons in the Caucasian tabulations), I point out that several Indian subsamples are equally high (though Morton amalgamated all North American Indians and never reported averages by subgroup), and that all Teutonic and Anglo-Saxon averages are either miscalculated or biased in Morton’s table.
Conclusions
Morton’s finagling may be ordered into four general categories:
1. Favorable inconsistencies and shifting criteria: Morton often chose to include or delete large subsamples in order to match group averages with prior expectations. He included Inca Peruvians to decrease the Indian average, but deleted Hindus to raise the Caucasian mean. He also chose to present or not to calculate the averages of subsamples in striking accord with desired results. He made calculations for Caucasians to demonstrate the superiority of Teutons and Anglo-Saxons, but never presented data for Indian subsamples with equally high averages.
2. Subjectivity directed toward prior prejudice: Morton’s measures with seed were sufficiently imprecise to permit a wide range of influence by subjective bias; later measures with shot, on the other hand, were repeatable, and presumably objective. In skulls measured by both methods, values for shot always exceed values for the light, poorly packing seed. But degrees of discrepancy match a priori assumptions: an average of 5.4, 2.2, and 1.8 cubic inches for blacks, Indians, and whites, respectively. In other words, blacks fared poorest and whites best when the results could be biased toward an expected result.
3. Procedural omissions that seem obvious to us: Morton was convinced that variation in skull size recorded differential, innate mental ability. He never considered alternate hypotheses, though his own data almost cried out for a different interpretation. Morton never computed means by sex or stature, even when he recorded these data in his tabulations—as for Egyptian mummies. Had he computed the effect of stature, he would presumably have recognized that it explained all important differences in brain size among his groups. Negroids yielded a lower average than Caucasians among his Egyptian skulls because the negroid sample probably contained a higher percentage of smaller-statured females, not because blacks are innately stupider. The Incas that he incl
uded in the Indian sample and the Hindus that he excluded from the Caucasian sample both possessed small brains as a consequence of small body size. Morton used an all-female sample of three Hottentots to support the stupidity of blacks, and an all-male sample of Englishmen to assert the superiority of whites.
4. Miscalculations and convenient omissions: All miscalculations and omissions that I have detected are in Morton’s favor. He rounded the negroid Egyptian average down to 79, rather than up to 80. He cited averages of 90 for Germans and Anglo-Saxons, but the correct values are 88 and 89. He excluded a large Chinese skull and an Eskimo subsample from his final tabulation for mongoloids, thus depressing their average below the Caucasian value.
Yet through all this juggling, I detect no sign of fraud or conscious manipulation. Morton made no attempt to cover his tracks and I must presume that he was unaware he had left them. He explained all his procedures and published all his raw data. All I can discern is an a priori conviction about racial ranking so powerful that it directed his tabulations along preestablished 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.
The American school and slavery
The leading American polygenists differed in their attitude toward slavery. Most were Northerners, and most favored some version of Squier’s quip: “[I have a] precious poor opinion of niggers … a still poorer one of slavery” (in Stanton, 1960, p. 193).
But the identification of blacks as a separate and unequal species had obvious appeal as an argument for slavery. Josiah Nott, a leading polygenist, encountered particularly receptive audiences in the South for his “lectures on niggerology” (as he called them). Morton’s Crania Aegyptiaca received a warm welcome in the South (in Stanton, 1960, pp. 52–53). One supporter of slavery wrote that the South need no longer be “so much frightened” by “voices of Europe or of Northern America” in defending its “peculiar institutions.” When Morton died, the South’s leading medical journal proclaimed (R. W. Gibbs, Charleston Medical Journal, 1851, quoted in Stanton, 1960, p. 144): “We of the South should consider him as our benefactor, for aiding most materially in giving to the negro his true position as an inferior race.”
Nonetheless, the polygenist argument did not occupy a primary place in the ideology of slavery in mid-nineteenth-century America—and for a good reason. For most Southerners, this excellent argument entailed too high a price. The polygenists had railed against ideologues as barriers to their pure search for truth, but their targets were parsons more often than abolitionists. Their theory, in asserting a plurality of human creations, contradicted the doctrine of a single Adam and contravened the literal truth of scripture. Although the leading polygenists held a diversity of religious attitudes, none were atheists. Morton and Agassiz were conventionally devout, but they did believe that both science and religion would be aided if untrained parsons kept their noses out of scientific issues and stopped proferring the Bible as a document to settle debates in natural history. Josiah Nott stated his goal in a forceful way (Agassiz and Morton would not have put it so baldly): “… to cut loose the natural history of mankind from the Bible, and to place each upon its own foundation, where it may remain without collision or molestation” (in Stanton, 1960, p. 119).
The polygenists forced defenders of slavery into a quandary: Should they accept a strong argument from science at the cost of limiting religion’s sphere? In resolving this dilemma, the Bible usually won. After all, scriptural arguments for supporting slavery were not wanting. Degeneration of blacks under the curse of Ham was an old and eminently functional standby. Moreover, polygeny was not the only quasi-scientific defense available.
John Bachman, for example, was a South Carolina parson and prominent naturalist. As a committed monogenist, he spent a good part of his scientific career attempting to refute polygeny. He also used monogenist principles to defend slavery:
In intellectual power the African is an inferior variety of our species. His whole history affords evidence that he is incapable of self-government. Our child that we lead by the hand, and who looks to us for protection and support is still of our own blood notwithstanding his weakness and ignorance (in Stanton, 1960, p. 63).
Among nonpolygenist, “scientific” defenses of slavery, no arguments ever matched in absurdity the doctrines of S. A. Cartwright, a prominent Southern physician. (I do not cite these as typical and I doubt that many intelligent Southerners paid them much attention; I merely wish to illustrate an extreme within the range of “scientific” argument.) Cartwright traced the problems of black people to inadequate decarbonization of blood in the lungs (insufficient removal of carbon dioxide): “It is the defective … atmospherization of the blood, conjoined with a deficiency of cerebral matter in the cranium … that is the true cause of that debasement of mind, which has rendered the people of Africa unable to take care of themselves” (from Chorover, 1979; all quotes from Cartwright are taken from papers he presented to the 1851 meeting of the Louisiana Medical Association.)
Cartwright even had a name for it—dysesthesia, a disease of inadequate breathing. He described its symptoms in slaves: “When driven to labor … he performs the task assigned to him in a headlong and careless manner, treading down with his feet or cutting with his hoe the plants he is put to cultivate—breaking the tools he works with, and spoiling everything he touches.” Ignorant Northerners attributed this behavior to “the debasing influence of slavery,” but Cartwright recognized it as the expression of a true disease. He identified insensibility to pain as another symptom: “When the unfortunate individual is subjected to punishment, he neither feels pain of any consequence … [nor] any unusual resentment more than stupid sulkiness. In some cases … there appears to be an almost total loss of feeling.” Cartwright proposed the following cure:
The liver, skin and kidneys should be stimulated to activity … to assist in decarbonizing the blood. The best means to stimulate the skin is, first, to have the patient well washed with warm water and soap; then to anoint it all over with oil, and to slap the oil in with a broad leather strap; then to put the patient to some hard kind of work in the open air and sunshine that will compel him to expand his lungs, as chopping wood, splitting rails, or sawing with the crosscut or whip saw.
Cartwright did not end his catalogue of diseases with dysesthesia. He wondered why slaves often tried to flee, and identified the cause as a mental disease called drapetomania, or the insane desire to run away. “Like children, they are constrained by unalterable physiological laws, to love those in authority over them. Hence, from a law of his nature, the negro can no more help loving a kind master, than the child can help loving her that gives it suck.” For slaves afflicted with drapetomania, Cartwright proposed a behavioral cure: owners should avoid both extreme permissiveness and cruelty: “They have only to be kept in that state, and treated like children, to prevent and cure them from running away.”
The defenders of slavery did not need polygeny. Religion still stood above science as a primary source for the rationalization of social order. But the American debate on polygeny may represent the last time that arguments in the scientific mode did not form a first line of defense for the status quo and the unalterable quality of human differences. The Civil War lay just around the corner, but so did 1859 and Darwin’s Origin of Species. Subsequent arguments for slavery, colonialism, racial differences, class structures, and sex roles would go forth primarily under the banner of science.
† My original report (Gould, 1978) incorrecdy listed the modern Caucasian mean as 85.3. The reason for this error is embarrassing, but instructive, for it illustrates, at my expense, the cardinal principle of this book: the social embeddedness of science and the frequent grafting of expectation upon supposed objectivity. Line 7 in Table 2.3 lists the range of Semitic skulls as 84 to 98 cubic inches for Morton’s sample of 3. However, my original paper cited a mean of 80—an obvious impossibility if the smalles
t skull measures 84.1 was working from a Xerox of Morton’s original chart, and his correct value of 89 is smudged to look like an 80 on my copy. Nonetheless, the range of 84 to 98 is clearly indicated right alongside, and I never saw the inconsistency—presumably because a low value of 80 fit my hopes for a depressed Caucasian mean. The 80 therefore “felt” right and I never checked it. I am grateful to Dr. Irving Klotz of Northwestern University for pointing out this error to me.
THREE
Measuring Heads
Paul Broca and the Heyday of Craniology
No rational man, cognisant of the facts, believes that the average negro is the equal, still less the superior, of the average white man. And, if this be true, it is simply incredible that, when all his disabilities are removed, and our prognathous relative has a fair field and no favor, as well as no oppressor, he will be able to compete successfully with his bigger-brained and smaller-jawed rival, in a contest which is to be carried on by thoughts and not by bites. —T. H. HUXLEY
The allure of numbers
Introduction
Evolutionary theory swept away the creationist rug that had supported the intense debate between monogenists and polygenists, but it satisfied both sides by presenting an even better rationale for their shared racism. The monogenists continued to construct linear hierarchies of races according to mental and moral worth; the polygenists now admitted a common ancestry in the prehistoric mists, but affirmed that races had been separate long enough to evolve major inherited differences in talent and intelligence. As historian of anthropology George Stocking writes (1973, p. lxx): “The resulting intellectual tensions were resolved after 1859 by a comprehensive evolutionism which was at once monogenist and racist, which affirmed human unity even as it relegated the dark-skinned savage to a status very near the ape.”