CAUSES OF IDIOCY.
It will be utterly impossible in the short time allotted to me, to enter at any length upon the various causes of idiocy, a study of which is, however, fraught with many a useful lesson. Suffice it to say that as the cause is always antecedent to any personal history of the child, idiocy is never dependent on the idiot himself, who has never become so through any vices of his own; he being in many instances the feeble expression of parental defects, and sometimes of parental vices, and is therefore more an object for commiseration than certain lunatics, who, in many instances, have become so through faults of their own. As to the social aspect of idiocy, it recognises no distinction of rank; it may occur in the homes of the affluent, or in the hovels of the most indigent. It is found in all civilised countries, but it is not an evil necessarily inherent in society, and is the result of the violation of natural laws, in some way or other, and at some time or other, and the effect may not show itself for two or three generations. A very large class of persons ignore the conditions upon which health and reason can co-exist; they pervert the natural appetites of the body, and the natural emotions of the mind, and thus bring down the awful consequences of their own ignorance upon the heads of their unoffending children.
Idiocy may be a congenital infirmity, or may be developed in early infancy. In the first category, the cause must necessarily be traced to intra-uterine life, and must be sought for in the history of the parents; in the second class, the cause may sometimes depend upon parental defects, and sometimes is due to a cerebral affection occurring soon after birth, but even in this class of cases, hereditary predisposition must be considered as a powerful factor in the genesis of the disease. In fact, the development of idiocy, whether congenital or otherwise, is in most instances to be attributed to an hereditary morbid vice, and it is one of the most common and striking forms of the degeneration of the human species.
Hereditary tendencies have much to do with the development of physical defects and bodily ailments, and this result is especially apparent in diseases of the nervous system; and there can be no doubt that heredity is a potent factor in the production of idiocy. Dr. Ireland says, "idiocy is, of all mental derangements, the most frequently propagated by descent;" and the statistics of Ludwig Dahl, of Christiana, showed that fifty per cent. of idiots had insane relations, those of Dr. Fletcher Beach showed a history of hereditary predisposition in 76 per cent., whilst those of Moreau, of Tours, give a proportion as high as 90 per cent.
In thus expressing myself, I should be sorry that my remarks should be construed as intended to cast any imputation upon those who have unfortunately an idiot in their family; the cause of the evil may be in some remote progenitor, for the transmission of the infirmity is not always direct, and the neurotic tendency may skip a generation, or be traced even further back.
Intemperance. One of the most fruitful causes of idiocy is the abuse—mark, I do not say the proper use—of alcoholic stimulants, which tends to bring families into a low and feeble condition, which thus becomes a prolific cause of idiocy in their children. From a report on idiocy, by Dr. Howe and other Commissioners appointed by the Governor of Massachusetts to ascertain the causes of this calamity in that State, it is stated that "out of 359 idiots, the condition of whose progenitors was ascertained, 99 were the children of inveterate drunkards;" and the report goes on to say further, "that when the parents were not actually habitual drunkards, yet amongst the idiots of the lower class, not one quarter of the parents could be considered as temperate persons. From a table drawn up by the late Dr. Kerlin, an American physician, in which the causes of the infirmity are given in 100 cases of idiotic children, I observe that in 38 of the number, intemperance on the part of the parents is traced as an accessory, main, direct, or indirect cause.
At the annual meeting of the British Medical Association, held at Cambridge, Dr. Fletcher Beach read a paper on the Intemperance of Parents as a predisposing cause of idiocy in children. In 430 patients, he was enabled to trace a history of parental intemperance in 138 cases, or 31·6 per cent.; of this number, 72 were males and 66 females."[5]
Other observers lay less stress upon parental intemperance as a cause of idiocy. Dr. Wilbur found that out of 365 cases in the State of Illinois, only eight cases were assigned to the abuse of drink in the parents; and Dr. Shuttleworth could trace this cause in only 16·38 per cent. of the cases observed by himself and by Dr. Fletcher Beach;[6] the same writer, under the head of toxic idiocy, mentions the case of an idiot boy, who was said to have been brought up on porter instead of milk. It will therefore be seen that there exists a great difference of opinion about the influence of intemperance of the parent in the causation of idiocy; but although statistics may vary upon this point, there cannot be a doubt that the children of drunken parents inherit an unhealthy nervous system, which in many cases culminates in idiocy.
Idiocy is especially prevalent in Norway, and Ludwig Dahl, a Norwegian writer, says that to the abuse of brandy, especially in the fathers, but also in the mothers during pregnancy, may be assigned an important, perhaps the most important, influence in the production of the large number of idiots in that country.
In considering this question, we must bear in mind that intemperance is only a relative term; for in the early part of the century we read of our ancestors indulging in a bottle of port wine to each individual, without, it seems, incurring the charge of drunkenness. There cannot be a doubt, however, that the habitual use of alcohol, without being carried to the extent of actual intoxication, is calculated to cause a low and feeble condition of the body, and thus conduce to the production of idiocy in the offspring; for we may fairly assume that what too severely tries the nervous system in one generation will appear in their descendants.[7] Without, therefore, exaggerating the influence of alcohol on the genesis of idiocy, I think I shall not be deviating from the path of strict scientific accuracy, if I say that over indulgence in alcoholic beverages is calculated to produce a low state of vitality, and a degeneration of nerve tissue which may culminate in the development of idiocy in subsequent generations.[8]
Just now that the attention of the Legislature is being prominently called to the treatment of habitual drunkards, it cannot be too widely known that their innocent offspring are but too frequently the victims of the brutish excesses of their parents, who, a few years ago, were well described by the then Secretary of State for the Home Department, when receiving a deputation on the subject, as not quite criminals nor quite lunatics, although nearly approaching both classes in many cases. The above statistics fully corroborate the pertinency of Lord Cross's remarks.
I do not allude to these facts with the view of casting any reflection upon the poor, honest, and temperate East Anglian labourer, who may be afflicted with the calamity of having an idiot child; but I merely mention them in order that they may serve as an additional caution against habits of intemperance, and may strengthen the hands of that noble band of philanthropists who are endeavouring to check the torrent of this hideous vice so prevalent in the present day.
Consanguine Marriages. There is no point connected with the causation of idiocy that has given rise to so much controversy as the marriage of near relations; formerly one of the most popular notions was that consanguineous marriages were among the most common causes of idiocy, whereas the researches of later observers have tended to modify, to a considerable extent, this sweeping assertion.
Different observers have furnished different results, as to the proportion of idiots found to be the offspring of consanguine marriages; thus Dr. Grabham's statistics give the proportion as about 2 per cent., Dr. Langdon Down's rather more than 5 per cent., and Dr. Shuttleworth's less than 5 per cent. The statistics of the Eastern Counties' Asylum, kindly supplied to me by Mr. Turner, the Resident Superintendent, show that about 6·5 per cent. were the offspring of cousins.
Of 359 cases observed by Dr. Howe, 17 were known to be the children of parents nearly related in blood. The history of these 17 families, the heads of which being blood relatives intermarried, showed that there were other causes to increase the chances of an infirm offspring, besides that of intermarriages, as most of the parents were intemperate or scrofulous; some were both the one and the other. There were born unto them 95 children, of whom 44 were idiotic, 12 others were scrofulous and puny, one was deaf, and one was a dwarf! In one family of 8 children, 5 were idiotic.[9]
Dr. Ireland, who has investigated this point with great minuteness, pertinently remarks that it has been the custom to collect instances of cousins who have married, and have had unhealthy children, as if this never happened to anyone else; and he adds that "the proper way to examine the question clearly, is to find what is the proportion of marriages of blood relations in a given population, and then to inquire if there be in the issue of such marriages a larger percentage of insane, idiotic, or otherwise unhealthy children."[10]
There cannot be a doubt that consanguinity has hitherto been considered too great a factor in the production of idiocy, and that in weighing the evidence, we must not lose sight of the fact that in many cases recorded, other factors beside intermarriage of relatives have contributed concurrently to the development of the mental defect.[11]
Educational Overpressure. There is one cause of idiocy which has been pointed out by Dr. Séguin, and which he says is due to the unsatisfactory social conditions under which women of the present day exist. "As soon," he says, "as women assumed the anxieties pertaining to both sexes, they gave birth to children whose like had hardly been met with thirty years ago."[12]
Great prominence has lately been given to this subject by an oration on "Sex in Education," by Sir James Crichton Browne, at the Medical Society of London, in which he called attention to the "growing tendency to ignore intellectual distinctions between the sexes, to assimilate the education of girls to that of boys, and to throw men and women into industrial competition in every walk of life." Elsewhere, he adds, that "to throw women into competition with men is to insure to them a largely increased liability to organic nervous disease.... Woe betide the generation that springs from mothers amongst whom gross nervous degenerations abound." Sir J.C. Browne supports his views by showing that there are organic cerebral differences between men and women, and that therefore they must be educated in different ways, being destined to play different parts on the stage of human life.[13]
The above views of Sir J.C. Browne have not remained unchallenged, and the eminent psychologist has found uncompromising opponents in Mrs. Garrett Anderson and others, who stoutly refuse to recognise the position of the "Tacens et placens uxor" of old-time dreams. Mrs. Anderson, who, I need scarcely add, writes most temperately upon this matter, in alluding to Sir J.C. Browne's assumption of the intellectual difference between men and women, remarks, "All I would venture to say is that, if it could be proved that an average man differs from an average woman as much as Newton differed from a cretin, it would still be well to give the cretin all the training which he was capable of receiving.... When we hear it said that women will cease to be womanly if they enter professions or occasionally vote in parliamentary elections, we think that those who conjure up these terrors should try to understand women better, and should rid themselves of the habit of being frightened about nothing."[14]
The limits of this essay will not permit me to dwell at any great length on the important question under consideration. There cannot be a doubt that the tendency of the present age is to encourage women to choose careers and to accept burdens unfitted for them. In thus expressing myself, I distinctly deprecate any hostility to the woman's movement of the present day, which rests on the claim for women for an open career; and I should be glad to see our universities ignore the ancient and exploded prejudices, which led to the long subjection of women to hardship and inequality. They ask for the same facilities as are enjoyed by men, and they have amply shown that they can compete with men in intellectual pursuits, and all they ask is to be allowed to compete on equal terms. I therefore cordially welcome the gradual emancipation of women from comparative subjection to comparative freedom; but the multifarious fields of energy and usefulness open to modern women, have brought with them disadvantages as well as gains.
Whilst, therefore, unreservedly admitting the claims of the fin de siècle woman to freedom of action and to intellectual equality, I must think there are certain branches of study, described by a modern writer as belonging to the "gynagogue" class, which are less suited to women than some others; and amongst these, I would name the abstruse study of mathematics, for although success in this branch of knowledge may lead to a brilliant career as a high wrangler, I think that a female mathematical athlete is not suited for the duties and responsibilities of maternity, and that the mental endowments of her children are likely to be below the average.
I am quite aware that I am treading on dangerous and delicate ground, but although I would not discourage the highest aspirations of women, whether of an intellectual, social, or æsthetic character, I must think that a word of caution is necessary against the overpressure of the present day in the direction above indicated.[15] With every desire to treat this question from a liberal point of view, I desire to emphasise the fact that men and women have different parts to play on the stage of life, and should be trained differently; but provided mental overpressure is guarded against, I have no fear of women engaging in certain occupations which custom has not hitherto recognised as feminine, and experience has shown us that they may be safely left to follow the promptings of their own powers and instincts.
Amongst the various other predispositions to idiocy, I would mention scrofula, which, according to Dr. Ireland, is the remote cause of two-thirds of all cases; phthisis and epilepsy in the parents are also potent factors in the development of idiocy in their offspring.
Before quitting the question of the cause of idiocy, I should like to say a word or two about what is technically called its histology and its pathological anatomy. What is there in the brain that makes one man a senior wrangler and another an idiot? What is it that unfits one person for the discharge of the ordinary duties of domestic and social life, and endows another with capacities adapted for a statesman, a mathematician, or a philosopher? Is it a defect in the quantity or in the quality of the nervous matter of the brain? Does it depend on a malformation of the cranium, on the size or shape of the head? does the form of a cranium illustrate the quality of the mind whose cerebral substratum it encloses, or can genius of a high order enshrine itself in a comparatively narrow and malconstructed tenement?[16] Does mental capacity depend on the size or weight of the brain, or on the degree of complexity of the cerebral convolutions, or on their symmetry in each hemisphere?[17] Upon this point, I am bound to tell you that science speaks with a somewhat uncertain sound, volumes having been written upon it without any definite solution or tangible result.
An eminent Italian psychologist, Dr. Mingazzini, in a recent work on the study of the cerebral convolutions, shows that in men of genius, the brain offers no certain indications of intellectual eminence, either by the greater richness of the frontal or the parietal lobes; and in support of this opinion he cites the researches of Wagner, which showed that, in the development and richness of the convolutions, the brains of many celebrated Gottingen professors were inferior to those belonging to individuals of low intellectual capacity.[18]
The average brain weight in man may be said to range from 40 to 52½ ounces, and in women from 35 to 37½ ounces; the question of the increase in size and weight of the brain, in proportion to intellectual power, is by no means determined; statistics exist of the weight of 23 eminent men, the list being headed by Cuvier, the naturalist, whose brain weighed 64½ ounces, whilst that of the orator, Gambetta, weighed only 39 ounces, being much below the average weight in the adult male; an imbecile died at the Montrose Asylum, whose brain weighed 63 ounces, and the heaviest brain on record, which weighed 67 ounces, was that of a bricklayer, who could neither read nor write; it must therefore be conceded that no definite statement can be made as to the relation that brain weight has to intelligence.[19]
It was formerly supposed that idiots always presented some obvious malformation of the cranium or skull. This is by no means necessarily the case; one of the most remarkable cases of idiocy that has come under my notice was that of a child with a well-formed head, remarkably handsome face, and a well-proportioned body.
Dr. Ireland says, "the principal anomalies met with in the skull of genetic idiots are flatness of the head behind, a rapid slope of the clivus, an osseous rim round the foramen magnum, unsymmetrical size of the cavities on each side, irregularities in the wings of the sphenoid, and differences in the size and shape of the jugular and other foramina; but these appearances are not constant, and often the skull is quite regular, both in structure and capacity."[20]
One of the most noted writers on the subject, after stating that a number of scientific men had spent thirty years in measuring and weighing the heads of idiots, sums up their conclusions as follows:—
1st. There is no constant relation between the development of the cranium and the degree of intelligence.
2nd. The dimensions of the anterior part of the cranium, and especially of the forehead, are, at least, as great among idiots as others.[21]
3rd. Three-fifths of idiots have larger heads than men of ordinary intelligence.
4th. There is no constant relation between the degree of intelligence and the weight of the brain.[22]
5th. Sometimes the brain of idiots presents no deviation in form, colour, and density from the normal standard; it is, in fact, perfectly normal.
After such a statement as this, I can readily imagine that some of you may say, it seems to us that you doctors really know but little about the genesis of idiocy. I am afraid this is, to some extent, true. We are only on the threshold of inquiry, and science of to-day is unable to bridge over the gulf that separates matter from mind.
Modern investigation, however, does not quite bear out the above sweeping statements in their integrity, although the most conflicting theories have been enunciated. Doubtless, attention has been too much concentrated on the gross morphology of the brain, without taking into account microscopical appearances. Dr. Shuttleworth, in giving the result of his long experience at the Royal Albert Asylum says, "We have occasionally found, when least expected, extraordinary defects in brain conformation;... microscopic examination will discover in many instances some abnormality of structure, such as the preponderance of simply formed braincells devoid of processes, denoting persistence of fœtal structures; or, on the other hand, degenerative changes resulting from inflammatory atrophy."[23]
Professor Luys, of Paris,[24] gives the result of the examination of the brain of 14 idiots, the anomalies observed being want of symmetry in the frontal lobes, and partial atrophy of the cortical folds especially of the frontal convolutions.[25]
Quite recently, Dr. Andriessen, at a meeting of the Leeds and West Riding Medico-Chirurgical Society, exhibited specimens of the brains of epileptic idiots, which showed conditions of microgyria with atrophy and sclerosis of the convolutions.
In considering the pathology of idiocy, I think sufficient attention has not been given to the chemical constitution of the cerebral substance. The most extravagant notions were at one time prevalent as to the rôle played by phosphorus in the animal economy; the Dutch naturalist, Moleschott, maintaining that "without phosphorus there was no thought." A celebrated chemist, Couerbe, also considered phosphorus to be the exciting principle of the brain, and according to him, the brain of ordinary men contained 2½ per cent. of phosphorus, that of the idiot 1½, and that of the madman 4 to 4½; from these data he concluded, "that the absence of phosphorus in the brain reduced man to the condition of the brute; that a great excess of this element irritated the nervous system and plunged the individual into the frightful delirium which we call madness; and that a medium proportion re-established the equilibrium and produced the admirable harmony which is none else than the soul of the spiritualists."[26] Professor Janet, in criticising the above theory, remarks that the brain of fishes, who do not pass for great thinkers, contains a large amount of phosphorus, also that the statistics of M. Lassaigne have shown that the brain of madmen does not contain more phosphorus than that of sane individuals.[27]
The late Bishop of Carlisle, in rebutting this phosphorus theory, remarks, "Why should we not go further and assert that there could be no thought without carbon or without any other element of which the human body is composed; for you can have no actual thought without a living creature, and no living creature without a body, and no body without carbon."[28]
I have treated the subject of the Chemistry of the Brain at considerable length in my treatise on "Aphasia and the Localisation of Articulate Language," to which book I would refer those who desire further information in reference to the connection between the amount of phosphorus and intellectual vigour.