Popular Science Monthly/Volume 31/August 1887/Correspondence
MEN'S AND WOMEN'S BRAINS.
AN answer to Miss Helen H. Gardener and the "Twenty of the Leading Brain-Anatomists, Microscopists, and Physicians of New York."
Dear Sir: In the June number of the "Monthly" I find a communication entitled "Sex and Brain-Weight," signed Helen H. Gardener, and indorsed, as she says, by "twenty of the leading brain-anatomists, microscopists, and physicians of New York," which assumes to be in some measure a reply to my paper, in the April number, on "Brain-Forcing in Childhood." The tone of the letter is so bad, and it is written in so unscientific a spirit, that I have hesitated whether or not to notice it with an answer. But, lest silence should be held by some to imply that the assertions of the writer of the letter in question are entitled to weight, I have thought it better to ask the indulgence of a little space in your columns. I will premise by saying that I have no disposition to enter into a controversy on a subject that is at present, so far as I am concerned, of altogether secondary importance to the one to which my paper on "Brain-Forcing in Childhood" mainly relates, and that I shall not again in the present connection ask any similar favor at your hands.
With Miss Gardener's opinions of my antagonism to the female sex I shall not stop to argue. I have only to say that no one is more in favor than myself of woman's intellectual advancement, and that in all that I have said or done in recent years in relation to this subject I have recognized the natural equality of woman's brain with that of a man so far as mentality as a whole is concerned. I have only contended that her brain is different from that of man, and that a fortiori her mind must also be different. I am in favor of "girls and women" using all the means of development of which they can avail themselves, and which are of such a character as to fit them for the duties of their sex. I am very sure that in many respects—as, for instance, in the study of music, of painting, sculpture, literature, and many of the sciences—their opportunities are as great as those of men, and I regret that they have not made better use of them. I am opposed to their study of military science, or of such branches of knowledge as they are not likely to use in their lives, as a mere system of routine, just as I am opposed to similar procedures in boys.
Quoting from my paper, I repeat, "The skull of the male of the human species is of greater capacity than that of the female, and it is a singular fact that the difference in favor of the male increases with civilization."
Now let me bring forward some of the authorities for this statement in order that Miss Gardener may submit them to the "twenty of the leading brain-anatomists, microscopists, and physicians of New York," whoever they may be, who appear to have as little knowledge of the subject as she baa herself.
I may say that there is no authority known to anthropologists that denies that the capacity of the average male skull is greater than that of the female. Miss Gardener and the "twenty leading brain-anatomists," etc., have only to refer to the "Revue d'Anthropologie," tome ii, series 1873, No. 3, page 481, for citations on this point in regard to twenty six different nationalities, and in every one of them the difference is marked. Relative to the second assertion, that the difference is greater in the civilized than in the uncivilized nations, I find in that table that Huschke determined that in twenty-one German men the average capacity of the cranium was 1,538·76 cubic centimetres, while the average in eighteen German women was but 1,265·23 cubic centimetres, showing a difference of 273·53 cubic centimetres in favor of the male skull. In twenty-one male English skulls, Barnard Davis found the average capacity to be 1,595·33 cubic centimetres, while in eighteen female English skulls it was only 1,372·54 cubic centimetres, a difference in favor of the male skull of 272·79 cubic centimetres.
Looking now at the lower races, we see that Barnard Davis, in twelve male Australian skulls, found the average capacity to be 1,316·85 cubic centimetres, while in the skulls of three Australian women the average was 1,273.08 cubic centimetres, a difference of only 43·77 cubic centimetres. In nine male negroes of Dahomey, he found the average skull capacity to be 1,493·88 cubic centimetres, and of three female negroes 1,412·33 cubic centimetres, a difference of 81·55 cubic centimetres. I could easily quote other figures to a like effect, but the foregoing are sufficient to establish the correctness of my assertion. If Miss Gardener and the "twenty leading brain-anatomists," etc., desire further information on this point, I would refer them to the "Dei Carateri Sessuali del Cranio Umano," by Paolo Mantegazza, published in the "Archivio per l'Anthropologia," vol. ii, 1872, or to the elaborate critical review thereof by M. A. Dureau, in the journal which I have already mentioned.
Miss Gardener appears to have looked into a copy of Topinard's "Anthropology," and perhaps the "twenty leading brain anatomists," etc., have done likewise, though that is doubtful. In any event, let her and them turn to page 145 of the English edition, and they will find the following words:
"The head of the woman is smaller and lighter, its contours more delicate, the surfaces smoother, the ridges and processes not so marked. The superciliary arches are but little prominent; the external half of the superior orbital border is thin and sharp (Broca). The forehead is vertical below, projecting above. The occipital condyles are small, as also the mastoid and styloid processes. The zygomatic arches are slender. The cranium in its ensemble is less high and longer," etc.
Some of these differences are absolutely inseparable from corresponding differences in the form of the brain.
Then, if they will refer to Carl Vogt's "Lectures on Man," page 90, they will find the differences between the male and female crania, due to civilization and barbarism, stated to the same effect as I have given them—that is, that they are more marked between the sexes in the civilized than in the uncivilized nations.
Now, in regard to the cause of this condition, Miss Gardener says that I "hold it to be a natural and unalterable difference in the brain-mass itself!" How she came to venture upon this assertion is a mystery to me, and I can only attribute it to that defective logical power which appears, for the present at least, to be a characteristic of most female minds. So far from saying anything of the kind, I offered two entirely different explanations of its cause: one to the effect that civilized women had not availed themselves of the advantages offered them, and hence had not developed their brains pari passu with those of men; or else that the work of barbarous men being very similar to that of their women, there had not existed the same necessity for an increased development of their brains.
Then Miss Gardener, without any notice to the reader that she has changed her source of information relative to my views, proceeds to quote from a paper of mine written several years ago, on the subject of "Women in Politics." To be sure, she mentions previously that she intends to quote from two of my papers; but no one reading her letter could believe otherwise than that she was citing extracts from the paper on "Brain-Forcing in Childhood," published in "The Popular Science Monthly" of April last. I have no copy of the other paper before me, it having been published in the "North American Review" several years ago; but doubtless she gives the words correctly, and I state them here with her comments as I find them in her letter:
"Dr. Hammond asserts, again, 'It is only necessary to compare an average male with an average female brain to perceive at once how numerous and striking are the differences existing between them' (the italics are mine). He submits a formidable list of striking differences, which include these: The male brain is larger, its vertical and transverse diameters are greater proportionally, its shape is quite different, the convolutions are more intricate, the sulci deeper, the secondary fissures more numerous, the gray matter of the corresponding parts of the brain decidedly thicker'; of this latter part the doctor modestly says that 'the evidence is not so full as might be desired.' But, as if all these were not quite enough to enable the merest novice to distinguish a male from a female brain, he offers these re-enforcements: 'It is quite certain, as the observations of the writer show, that the specific gravity of both the white and gray substances of the human brain is greater in man than in woman.'"
From this last remark she proceeds to draw the inference (in which doubtless she is sustained by the "twenty leading brain anatomists," etc.) that the greater prevalence of insanity among men than women is the result of the greater specific gravity of the brain, forgetting that the life of man is so much more active than that of woman, his liability to injuries so much greater, his addiction to the excessive use of alcohol so much more common, and his habits generally so much worse, as to constitute the real reasons why he is more liable than woman to become insane.
Moreover, she appears to be entirely ignorant of the facts, as are likewise doubtless the "twenty leading brain-anatomists," etc., that the specific gravity of the brain is increased in insane women as well as in insane men, and that, instead of being a cause, it is probably a consequence of the morbid processes to which the brain of the insane is subjected.
But, in regard to the description which I have given of the average female brain, I stand ready to prove its correctness, not. however, in the rough-and-tumble fashion proposed by Miss Gardener, but by a process by which all such determinations are made by those who know what they are about.
Suppose, for instance, I am describing a woman's thumb, and pointing out its differences from that of a man. I should say that it was shorter, smaller in circumference, that its articulations were not so prominent, that the processes on the bones for the attachments of muscles were not so well marked, that its muscular structure was more delicate, that the skin was softer, and finer, and freer from wrinkles, that the nail was longer in proportion to its width than that of man. Such would be the description of an average female thumb, as I see thumbs belonging to the ladies of my acquaintance.
Now, following Miss Gardener in the offer which she makes, and according to which—by my ability to select rightly in every instance—I am to gain or lose my case, I make this proposition to her:
I will agree to furnish twenty well-preserved thumbs, marked in cipher, if subjects can be obtained for the experiment, Miss Gardener or her "twenty leading brain-anatomists," etc., to divide the male from the female thumbs, by applying any knowledge they may possess on the subject.
Doubtless Miss Gardener and the "twenty leading brain-anatomists," etc., know a male from a female thumb when they see them, but I am quite sure that by judicious selection, I should be able to confound their judgment. I should take some of the male thumbs from small, delicate men who had never done any hard work, and who had taken good care of their hands by wearing gloves and availing themselves of the services of a manicure, while I should select some female thumbs from women whose hands are hardened and enlarged by exposure and toil, and to whom nail-brushes and soap-and-water are rarities. I am quite safe in saying that Miss Gardener and the "twenty leading brain-anatomists," etc., would find it impossible to select the ten male from the ten female thumbs, and I am equally certain that there is not an anatomist of the brain kind, or any other variety, who could accomplish the feat.
That there are female brains that are larger than male brains, of altogether superior development, and the possessors of which have greater intellectual power than is exhibited by some men, neither I nor any any one else, so far as I know, has ever denied. Miss Gardener can not be in ignorance of my views on this subject, for she quotes my words "average male and average female brain," and it is to the "average" female brain only that my description applies. A fair proposition would be the following, and, if Miss Gardener, from the resources at her command—"the collections" of the "twenty leading brain-anatomists," etc.—will supply the brains, I will agree to stand or fall by the result. Weigh one hundred male brains and then one hundred female brains: if the average weight of the male brains is not several ounces greater than that of the female brains, I lose my case. The only condition I make is that I shall be present when the brains are selected and weighed.
It is scarcely necessary, however, to repeat an experiment that has been performed by many anatomists in all parts of the civilized world. Thus, Welcker's observations show that the average male brain in Europeans is a little over forty-nine ounces, and the average female brain a little over forty-four ounces, a difference of about five ounces. The proportion existing between the two is therefore as 100:90. Huschke found the brains of adult man and woman to weigh respectively 1,410 grammes and 1,272 grammes. His observations, therefore, coincide very exactly with those of Welcker.
Calori not only found that the brain of man is heavier than that of woman, but he discovered the fact that the difference exists no matter what may be the form of the skull. Thus in men with brachycephalic skulls, the average weight of the brain was 1,805 grammes, while in brachycephalic women it was only 1,150 grammes. In the dolicocephali the average weight of the male brain was 1,282 grammes, whereas that of the female brain was 1,136 grammes.
Broca, in his paper "Sur le volume et la forme du cerveau," arranges from Wagner's elaborate table one which shows that this difference exists for all ages from twenty-one years to sixty and over. The results are given in grammes in the following table:
In fact, all authorities, without exception, save Miss Gardener and the "twenty leading brain-anatomists," etc., agree that the average European male brain is about five ounces heavier than the average female brain.
Another test that I am willing to abide by is the following, relating to the other characteristics that Miss Gardener quotes as having been laid down by me:
Let her, from the stores at her command, allow me to select from at least one hundred specimens an average female brain, and from a like number an average male brain. I will agree to point out to a competent brain-anatomist—not one of the "twenty," however—all the differences for which I have ever contended. By that test also I am willing to stand or fall.
I have never said, as Miss Gardener charges, that the sex of an infant could be determined by its brain, though Rüdinger declares that a typical point of difference between the male and the female brain can often be found at the seventh or eighth month of foetal life, and that the male has the frontal lobe better developed than has the female, and that there is an earlier development of the secondary fissures in it, and in the parietal lobe.
I commend this matter to the serious consideration of the "twenty leading brainanatomists," etc. I scarcely believe that any one of them, without reference to the "physical sex differences" referred to by Miss Gardener, could tell the sex of a three months-old infant by a minute inspection of all the rest of its body.
A word more in relation to the subject of the comparative weight of the brain in the two sexes. Miss Gardener and, presumably, the "twenty leading brain-anatomists," etc., deny that there is any superiority of brain-weight in the man over that of woman, and she instances the fact that the difference in the weight of some men's brains is greater than that existing between that of the sexes. No one questions that matter, so far as I know, but certainly nothing of any importance to her case is to be drawn from the fact. A like condition exists in regard to almost all parts of the body. Thus the average foot of a woman is smaller than the average foot of a man, yet the difference between the feet of some men is greater than the average difference between the foot of man and woman. The average ear of a man is larger than the average ear of a woman. Yet some women have prodigious ears, far exceeding in size the ears of some men; it would certainly not be correct to assume from these facts that a woman's foot or a woman's ear is larger than the corresponding members in man. It is with averages deduced from a large number of observations that we have to deal in matters of this kind and not with individual examples.
Dr. Thurnam gives the average brain weight of ten men who were remarkable for their intellectual development as 54·7 ounces, among them that of Cuvier, 64·5 ounces; Abercrombie, 63 ounces; Spurzheim, 55·6 ounces; Daniel Webster, 53·5 ounces; Lord Campbell, 53·5 ounces, and Chalmers, 53 ounces. Now, let Miss Gardener and the "twenty leading brain-anatomists," etc, search the records of anthropology and their own immense collections for the brain of a woman weighing as much as the least of these, that of Dr. Chalmers. I venture to say that there has never been in the history of the whole world a female brain, free from obvious disease, weighing more than fifty-six ounces, whereas there have been many male brains exceeding this by several ounces.
Next, in regard to the relative and absolute brain-weights in the two sexes and in animals generally, Miss Gardener shows that she is ignorant of the points involved. She quotes me as saying, "Numerous observations show beyond doubt that the intellectual power does not depend upon the weight of the brain relative to that of the body so much as it does upon absolute brain weight. (The italics are Miss Gardener's, who, not content with exercising the feminine proclivity of italicizing what she writes, takes that liberty to no small degree with what I have written.) This is true, but she does not understand in what its truth, for she goes on to assert that in accordance with its dictum the brains of the whale and of the elephant, being of vastly greater weight than the brain of man, the animals possessing them should be superior to man in intelligence. Here she very disingenuously or very ignorantly attempts to make it appear that I have declared absolute brain-weight, regardless of species and genera, and without reference to the structure of the organ, to be the test of intelligence; whereas, in everything that I have ever written with reference to this point, I have invariably expressed the diametrically opposite opinion. But, if the brain of a whale or that of an elephant had as large an amount of gray tissue and as complex a structure as that of man, it is very certain that then the whale and the elephant would stand at the head of all animated nature, and that man would be their slave. "The elephant, which disports himself for the amusement of small boys and the enrichment of Mr. Barnum," would be quite capable of causing the small boy and Mr. Barnum to amble, and gyrate, and to stand on their heads for his—the elephant's—amusement and that of his wife and children. It is not only in size that the male brain differs from that of woman, but that its structure and arrangement are also different.
The absolute brain-weight is, therefore, of little consequence, except when it relates to animals of the same species. A whale, with a brain weighing six or seven pounds, would be a more intelligent whale than one with a brain of four or five pounds. A man with a brain weighing sixty-five ounces is potentially a more intellectual man than the one with a brain of thirty-five ounces. In three individuals of very feeble intelligence Tiedemann found the weights of their brains to be 193, 253, and 221 ounces, respectively. Mr. Gore has reported the case of a woman, forty-two years of age, whose intellect was infantine, who could only speak a few words, whose gait was unsteady, and whose chief occupation was carrying and nursing a doll. After death the weight of her brain was found to be but ten ounces and five grains.
As to relative brain-weight, I do not attach much importance to it, as it is subject to variation according as the individual increases or diminishes in weight. Thus, if a man or a woman weighing one hundred and fifty pounds has a brain weighing three pounds the proportion of brain-weight to body-weight is as 1:50. But, suppose the person loses fifteen pounds in weight, then the proportion becomes 1:45, whereas if there should be a gain of a like amount the proportion would change to 1:55. In the first instance, if relative weight has anything to do with intelligence the mental power would be increased, while in the other case it would be diminished. Of course, no such change takes place.
Many years ago I made several thousand observations in regard to the weight and other qualities of the brains of various species of animals belonging to the classes of reptiles, fish, birds, and mammals. In these investigations I went over to a great extent the ground previously traversed by Leuret, and in some respects made new observations. I found among other interesting facts that the brain of the canary-bird, reared in the United States, was in weight as compared to the body as 1:10·5, and in the Arctic sparrow as 1:11. These little animals have the largest brains relative to the body of any others yet examined. To pretend that they are superior in intelligence to man, in whom the weight of the brain relative to that of the body averages 1: 36·50, is, of course, ridiculous. Yet that is the conclusion to which Miss Gardener, and presumably the "twenty leading brain-anatomists," etc., would have us come.
Broca declares that the difference in weight between the brain of woman and that of man is not due alone to the smaller size of her body, but to the additional fact that woman is in the mean, when compared to man, a little less intelligent; a fact, he says, which should not be exaggerated, but which is nevertheless real. This is going somewhat farther than I have ever gone, but what Broca says in a matter of anthropology is worthy of serious attention.
When Miss Gardener says that I make relative difference "count for a great deal" when existing between two men, she passes the limits of correctness. I have never said anything of the kind.
One more point, and I have done. I stated, in the paper on "Brain-Forcing in Childhood," that the human head does not grow after the seventh year, and Miss Gardener, with the assistance of the "foremost brain-anatomist of New York," is quite facetious over the assertion. Instead of head I should have said brain, and then the point involved would have been more correctly stated; for the scalp, muscles, fasciæ, etc., of the head have nothing to do with the issue which concerns the mind only as derived from the brain. In regard to the growth of the brain in size and weight, there is abundant authority for the statement that it ceases to advance at or about the seventh year. Soemmering states that the maximum is attained at three years. The brothers Wenzel, at between six and seven years; and Tiedemann, at between seven and eight years. Other observers have arrived at different results, but there is room for a difference of opinion on the subject, and Miss Gardener should have been aware of the fact when she dismissed the statement as though it were entirely unauthorized.
That the brain ceases to grow at a comparatively early age is abundantly established by the observations of several competent brain-anatomists. Thus, Dr. Boyd, who based his conclusions on the examination of over two thousand brains, found the average weight to be, at the age of from ten to twenty, 48·5 ounces the maximum weight for all ages, and four ounces heavier than in persons whose ages ranged from twenty to thirty.
Broca, quoting from Wagner's tables, gives the mean weight in persons of from ten to twenty years as 51·7 ounces heavier by 4·4 ounces than in persons from twenty to forty years of age.
The average weight of the brain in forty-seven persons of English, Scotch, and German nationality, as given by Thurnam in one of his tables, is 49·6 ounces in those whose ages range from ten to twenty years a weight considerably in excess of that shown for any other period of life.
The general truth of the assertion made in my paper on "Brain-Forcing in Childhood," that "the brain of a child is larger in proportion to its body than that of the adult" is, therefore, not only established, but the additional fact inferentially stated, that the brain is absolutely larger in childhood than in adults, is shown to be correct.
And now I must bring this communication to a close, feeling that I have given more attention to Miss Gardener than she and the "twenty leading brain-anatomists, microscopists, and physicians of New York" deserve, and advising them that before they again rush into print they make themselves to some extent acquainted with the elementary truths of the science of anthropology.
William A. Hammond.
THE EXPLOSION AT BRIGHTON, ILLINOIS.
Editor Popular Science Monthly:
Sir: The letter of Mr. A. O. Fay, published in No. 182, seems to call for a few words in reply, for Mr. Fay appears to have mistaken the purpose of the article to which he refers. In the first place, the entire aim of my article in No. 180 was to present the phenomena connected with the explosion of August 29, 1886, and not, as Mr. Fay seems to think, to generalize from a single phenomenon, nor to denounce the methods of building magazines at present adopted. A careful re-reading of the article in question, in the light of Mr. Fay's letter, fails to reveal any such denunciation, or illegitimate generalization.
In reference to the proper construction of powder-magazines, your correspondent clearly condemns the method adopted at Brighton, as shown in the three magazines personally examined, and which I was informed, by the agent in charge of one whose walls were injured in the explosion, was the plan of all. In this, of course, my source of information may have been at fault. But there is not one word in my article which can be tortured into a condemnation of this form of construction, though I did say that "a recent occurrence dangerously near Chicago has shown that it is by no means sufficient" as a matter of protection, and the town of Lake took a similar view. What I did characterize as very strange is the omission of any protection against lightning, and I may add that one of this same group of magazines was destroyed by lightning before, I think in 1879, though I have not the date at hand.
Then Mr. Fay says that "the simplest knowledge of the properties of dynamite would have prevented Professor Griffin from attributing the non-explosion of other magazines in the vicinity to the fact of their being beyond the limits where displacement would not appear." The words italicized are quoted in a garbled form, which gives them a very different meaning. Originally, they stood as parts of two sentences. This is an easy way of avoiding an explanation of the phenomena. My article suggests an explanation, does not give it as the only explanation; but there were the phenomena, and to deny my explanation, without any suggestion of another, is a good illustration of the method of destructive criticism now so popular: why does not Mr. Fay give his own explanation? Facts are sometimes stubborn things; and the circle of magazines and other buildings uninjured while those nearer the wrecked magazine were destroyed and those farther off were wrecked, is a fact.
I am very glad to be informed of my ignorance of the fact that other substances have taken the place of infusorial earth in the manufacture of dynamite; it would have been more gratifying had Mr. Fay told us what those substances arc—or is it now a "trade secret"? But I am at a loss to understand what he can mean by his statement that "it would practically be impossible to find offered for sale by any manufacturer or dealer any dynamite, in the compounding of which earth or any other inert matter had been used." Does dynamite, as now made, contain some substance that reacts chemically upon the nitro-glycerine? If so, the public would undoubtedly be glad to know it, as the danger in the storage of the substance is probably increased thereby.
Mr. Fay's method of quoting parts of sentences and making them appear as used in reference to different points from those to which they were applied does not seem to me quite fair.