Faculty of Biological Sciences, University of Leeds

These pages have been left in this location as a service to the numerous websites around the world which link to this content. The original authors are no longer at the University of Leeds, and the former Centre for Human Biology became the School of Biomedical Sciences which is now part of the Faculty of Biological Sciences.

Measuring Heads

Dr. D.R.Johnson

We saw last time how quantitation can be used to reinforce prejudice. Evolutionary theory pulled out the rug from the monogeniasts and polygenists about how many Adams there were, but satisfied both sides in presenting a better rationale for their shared racism. Alongside evolution came the lure of numbers - the idea that rigorous measurement meant irrefutable precision, a numerical biology as worthy as Newton's physics

Evolution and numbers were thus in a position to provide the basis for a scientific theory of racism - backed by lots of solid numbers. In fact once again the Blacks, women and the poor came out worst: because, of course, numbers are the root of creative interpretation. We still take the one possible result amongst many that reinforces our prejudices.

First of all, lets look at the quantification epidemic. Francis Galton, cousin of Darwin, Professor of Biometry at University College London was the prime 'counting man'. Galton would measure anything: he even proposed a study on the efficacy of prayer. He didn't actually do that, but he did construct a beauty map of the British Isles. He classified girls as good, medium and bad and carried in his pocket a piece of paper shaped like a cross with a long leg. He made a hole in the appropriate leg of the cross, hidden in his pocket with a mounted needle each time he passed a girl. London ranked highest, Aberdeen lowest. Galton also proposed a way of measuring boredom, according to the degree of fidgeting..

Galton set up a laboratory at the International Exposition in London in 1884 and measured heads for three pence. At the end you got an opinion as to your intelligence. When the Exposition closed Galton moved to a London museum, and carried on for six years. The laboratory became famous, and attracted many notables.

Numbers do not guarantee truth - Robert Bean and his brains

In 1906 Bean published a long technical article comparing the brains of blacks and whites. Everywhere he found cause to stress black inferiority. He took special pride in the corpus callosum, a tract connecting the two halves of the brain. Now higher functions sit at the front of the brain and vice versa, so the front of the corpus callosum should be larger in whites. So he plotted genu, at the front, against splenum, at the back in a large series of blacks and whites . There was a virtually complete separation between blacks and whites. Whites had a larger genu, hence more up front. All the more remarkable, said Bean, because the genu also contains olfactory fibres, and blacks have a better sense of smell. Within each race women have a smaller genu.

Throughout all this one measure is notably absent: there is no measure of brain size. It isn't that it wasn't done - it was, but there was no difference. Why aren't white (superior) brains bigger? Well, says Bean, the brains came from unclaimed bodies donated to Medical schools. We all know how blacks have less respect for their dead than whites, so the whites would of course be 'prostitutes or the depraved' whilst the Blacks might also contain representatives of the better classes. Hence, of course, the lack of difference - we are not comparing like with like.

Moll, Bean's mentor at John's Hopkins was cautious. Bean's results were just too good, too clear cut. Mall repeated the observations with the important difference that he did not know at the time whether a brain came from a black or a white, a male or a female. Using 106 brains, including 18 of Bean's Moll found - no difference .

This example teaches us four things:

  1. Scientific racists and sexists often confine their prejudice to one group. But race sex and social
  2. class all interact and racists often use other variables. Bean studied race but commented on sex and used social class to argue a point.
  3. Prior prejudice dictates conclusions, not numbers
  4. Numbers and graphs do not gain precision from increased sample size if experimental design is flawed.
  5. Craniometry leaks, as does all science. Bean's findings were repeated in the popular press.
Bean was either a fraud or a great self deluder: either way he was a poor scientist.

Paul Broca, professor of clinical surgery in Paris, was a much better scientist, and no fraudster. He believed that intelligence was related to the size of the brain. If not, then why had anthropologists devoted so much time to measuring the brain? The brain is
'in general larger in mature adults than in the elderly, in man than in woman in eminent men than in men of mediocre talent, in superior than in inferior races'

Here we go again.

And five years later
'A prognathous face, more or less black colour of the skin, woolly hair and intellectual and social inferiority are often associated, while more or less white skin, straight hair and an orthognathous face are the ordinary equipment of the highest groups in the human series'

Broca regretted this, but facts were facts, what could he do? Broca's hold on facts was good. His numbers are undoubtedly correct. He pioneered the use of lead shot, spent months on gauging the best size to use, how to tap the skull and the best type of measuring cylinder to pour shot into afterwards. He preferred, however, fresh brains, removed by his own hand at autopsy.

Tiedemann on the other hand said that there was no difference in brain size between white and black. Tiedemann used another imprecise measuring system: the blacks came out 45ml larger than in other peoples work: the whites came out the same. Interestingly Broca performed the same sort of hatchet job on Tiedemann as we did on Moreton in the last lecture. Broca said Tiedemann

'was dominated by a preconceived idea. He set out to prove that the cranial capacity of all human races is the same'

But Broca's numbers were good. How did he come to his racist conclusions? Well he didn't. He started from his conclusions, peered through his facts and picked the ones that fitted best. So we now have good numbers, but still rotten science.

Here is Cuvier, a great scientist, and to Broca's delight the possessor of the largest brain in France, on the 'Hottentot Venus' an African lady exhibited in Paris

'she had a way of pouting her lips exactly like what we have observed in the Orang utan. Her movements had something abrupt and fantastical about them, reminding one of the ape. Her lips were monstrously large. Her ear was like that of many apes, being small, the tragus weak ... these are animal characters'

So the game is to select 'meaningful' characteristics (not of course lip thinness, which makes Caucasians more ape-like than Blacks) and demonstrate that these are concordant with apes. Broca started off with radius:humerus, a higher ratio makes a longer 'ape like' forearm. At first all was well : whites 0.739, blacks 0.794. But an Eskimo gave 0.703, an Aborigine 0.709 and the Hottentot Venus 0.703. Of dear: either we must admit white inferiority or abandon the measure. Quite clearly the measure is flawed because Aborigines, Hottentots and Eskimos are, of course inferior to Blacks.

Broca ran up against the same problem with brain size. Perilously he found that several yellow races scored well. Eskimos, Lapps Mongolians and Tartars would all beat us on brain size. Quite clearly some inferior groups may have large brains, but small brains must belong exclusively to peoples of low intelligence. Unbeatable: deny it at one end, affirm it at the other so that it fits the prejudice.

In choosing what to measure Broca displayed similar logic. He distinguished between 'empirical' characteristics having no apparent design and rational characteristics. What made a character rational? Why of course

'they have an affinity in Negroes to those which they exhibit in apes and establish the transition between these and Europeans'

In other words bias towards the characters which display what you want to prove.

On another occasion

'We surmount the problem easily by choosing for our comparison of brains such races whose intellectual inequalities are completely clear. Thus the superiority of Europeans compared with African Negroes, American Indians, Hottentots, Australians and the Negroes of Ociania is sufficiently certain to serve as a point of departure for the comparison of brains'

This sort of thing was deeply established This illustration is from an anatomy text of 1903 and demonstrates that the step between Gauss the mathematician and a bushman is the same as that between a bushman and a gorilla.

Intelligence and brain size in white men

The idea of large intellects contained in large brains was also seductive. A fashion developed for post mortem weighing and measuring of the eminent. Powell and McGee, two American anthropologists made a bet with each other (though it is hard to see who benefited) and a league table started to emerge. Cuvier did well at 1830g, Turgenev broke the 2,000g barrier in 1900. At the other end was embarrassment. Walt Whitman (poet) 1282g, below average: Gall (founder of Phrenology) 1198g. Broca himself 1424g (about average). Gauss, the mathematician, weighed in at 1492g but was extremely convoluted at least compared to a Papuan.

Encouraged Gauss set out to weigh the brains of all recently dead professors at Gottingen (where he worked) . Of four dead and willing professors two weighed in at 1368 and 1226g. Broca excused this. The professors either died in extreme old age, or were very short and slight, or had suffered poor preservation. When these excuses were attacked by fellow scientists Broca countered :

'it is not very probable that 5 men of genius should have died within five years at the University of Gottingen ...a professorial robe is not necessarily a certificate of genius: there may be, even at Gottingen, some chairs occupied by not very remarkable men'

At this point Broca desisted

'The subject is delicate, and I must not insist on it any longer'

Another thorn in the side of craniometrists was the large size of the criminal brain. Broca dismissed it because sudden death by execution diminished the decrease in brain size produced by sickness and old age. In the year of his death a large study showed an average increase of 11g in the brains of 119 assassins, murderers and thieves. Broca was dead, but his successor Topinard suggested that success in crime, as elsewhere, demanded grey matter. Who shall decide between Moriarty and Holmes?

Progress and brain size

Broca's memorial was his work on brain size and civilisation: probably the best example ever of hope dictating conclusion. Broca considered himself a liberal: women's' brains were small because of socially enforced underuse. Given a changed society they might grow. Primitive tribes had small brains because of lack of intellectual challenge. But in Europe brain size had naturally increased with the march of civilisation.

Broca 'proved' this with the help of large samples from Parisian cemeteries. This gave the following figures:

12th century 1426ml
18th century 1409ml
19th century 1462ml

This was not looking good for the march of progress. Without knowing the variability it is hard to assess what is happening, but 3.5% difference suggests that all the samples are alike.

So what did Broca say? Well he was disappointed in the results from the eighteenth century, which should be intermediate. It must be social class. The 12th century sample was from a churchyard, so must represent gentry. The 18th century sample was from a common grave: the 19th century sample was mixed, 90 from individual graves with a mean of 1484ml, 35 from a common grave with a mean of 1403ml. So round we go in a circle, but each evasion made things worse. He now had two samples from common graves, the C18 larger on average than the C19: and in the C18 you got a better class of person in a common grave; before the revolution you had to be really rich to rest in a churchyard.

But yet more trouble: now that he had partitioned by social class he had to admit that one troublesome sample from a C19 hospital morgue had a larger average that one from a C19 churchyard. How could the unclaimed dead dregs of society outsmart the cram of C19 Paris. This explanation really takes the biscuit: morgues tended to be sited near rivers. They therefore contained large numbers of drowned people; many drownings are suicides; many suicides are insane; many insane people have surprisingly large brains.

Women's brains

Lastly we should consider women's' brains. Broca and his contemporaries collected masses of data on womens' brains, probably just because they provided a readily available source of material for comparison with men. Inferior groups are always interchangeable

'The Negro brain possesses a spinal cord of the type found in children and women and, beyond this, approaches the type found in higher apes'-Huschke 1854

By its rounded apex and less developed posterior lobe the Negro brain resembles that of our children, and by the porotruberence of the parietal lobe that of our females' - Vogt 1864

'Men of the black races have a brain scarcely heavier than that of white women' - Herve 1881

Broca worked on two sets of data, the present difference in brain size and the supposed widening of that difference through time. Based on autopsies in Parisian autopsies he found:

Males (n=292) 1325g
Females (n=140) 1144g

A difference of 14%. Broca understood that he had to compensate for body size: he had used such a process in a feud over French versus Germans. But he didn't attempt it because he knew that women were less intelligent than men anyway, the difference in brain size must be partly due to this and partly due to stature.

To record the widening of the gap with time Broca measured prehistoric skulls: he found 99.5ml difference as opposed to 130-220ml in modern times. This was explained by Topinard

'The man who fights for two or more in the struggle for existence, who has all the responsibility and cares of tomorrow, who is constantly active in combating the environment and human rivals, needs more brain than the woman whom he must protect and nourish , than the sedentary woman, lacking any interior occupations, whose role is to raise children, love and be passive'

The data was used for what must be the most vitriolic attack on women ever published

'In the most intelligent races, as amongst the Parisians there are a large number of women whose brains are closer in size to those of gorillas than to the most developed male brains. This inferiority is so obvious that no one can doubt it for a moment: only its degree is worth discussion'

The explanation, of course is the same as that for all inferior groups. Broca published height and age data for his post mortems. His women were older and, on average, six inches shorter. If we correct for this the difference is reduced by two thirds, and becomes statistically insignificant.

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