Chapter II: The Deaf as a Permanent Element of the Population (2)

On the other hand, we find the proportion of marriages resulting in deaf offspring and the proportion of deaf children much greater when there is congenital deafness in one or both parents, when one or both have deaf relatives, and greatest of all when these influences are combined. When one or both parents are congenitally deaf, the percentage of marriages resulting in deaf offspring is 13.1, and the percentage of deaf children is 12.1; when both parents are so, the percentages are doubled: 24.7 and 25.9. When one parent has deaf relatives and the other has not, the percentages are 6.6 and 6.4; when both have, the percentages are nearly four times as great: 23.5 and 20.9. When both parents are congenitally deaf but neither has deaf relatives, the percentages are 7.1 and 4.1. When both are adventitiously deaf and both have deaf relatives, the percentages are 17.5 and 9.6. When both are congenitally deaf and one has deaf relatives, the percentages are 16.3 and 20.0; and when both have deaf relatives, the percentages are 28.4 and 30.3.

The evidence is very strong, then, with regard to the form of deafness and the presence or absence of deaf relatives. In cases where the parents are not congenitally deaf and have no deaf relatives, the proportion of deaf children is very low. When one or both parents are congenitally deaf or have deaf relatives--when the deafness is inherited or in the family--the likelihood becomes far greater, and greater still when the two influences are in conjunction. In general, in respect to the influences of heredity upon deafness, the main determinants seem to be found in the existence in the parties, whether hearing or deaf, of deaf relatives, and, to a less extent, in the existence in parties who are deaf of congenital deafness.

POSSIBLE ACTION FOR THE PREVENTION OF CONGENITAL DEAFNESS

We come now to the consideration of the question of possible action for the prevention of congenital deafness. This examination naturally centers about the matter of the regulation of marriage, with due attention to the extent that action on the part of the state is to be regarded as desirable or feasible.

We have seen that congenital deafness may, hypothetically, be divided into three distinguishable classes: that in which consanguineous marriages are concerned, that in which there is antecedent deafness in the family, and that in which neither of these conditions occurs; and in our inquiry it has seemed best to take up each of these separately. It may be, however, that there is in fact no very radical difference between these several forms, and that with increased knowledge on the subject a more or less intimate relation will be found to exist.

Of that form of deafness in which neither consanguineous marriages nor antecedent deafness is involved, we are at present, as we have noted, able to say little definitely. In most cases we may be convinced that there exists in the parent some peculiar state of morbidity or other affection, latent or manifest, perhaps to some extent of hereditary influence, which has an effect on the organs of hearing of the offspring. A certain proportion is quite possibly due to recognizable defects both of physical and mental character. Our statistical evidence, however, in respect to this form of congenital deafness is too slight to warrant any positive deductions; and we will have to wait for further investigation to determine its nature fully. None the less, marriage of persons known to be liable to have ill effect on possible offspring is objectionable for not a few reasons, from the standpoint of the interests of society; and in their reduction there will probably be a greater or less diminution of congenital deafness.

With regard to consanguineous marriages and their effect on deafness we are on surer ground, so far as may be indicated by statistical data. This question is found in very great measure to be connected with that of deaf relatives in general. The matter appears to be largely a part of a law of wide application, namely, that in the blood relationship of parents the possibilities are intensified of the perpetuation of a certain strain, which holds true no less with the transmission of deafness. Consanguineous marriages are perhaps not of sufficiently frequent occurrence, so far as concerns the effect on deafness, to require special action; but in the consideration of such marriages in general, their part in the causation of deafness should have due weight; and whatever may be said regarding them in other relations, they are to be avoided if we wish to remove all chances of this kind of deafness resulting.

The problem of deaf relatives and their connection with congenital deafness is a very large one. Attention however, has mostly been focused upon it in relation to the intermarriage of the deaf and its effect upon their offspring. Indeed, in such unions there has already been more or less concern, and there has even been question whether it is a wise or unwise policy to allow the deaf to marry other deaf persons. The deaf, as we shall discover, not only find their companions for social intercourse among similar deaf persons, but _a fortiori_ very often seek such persons for their partners in marriage--in fact, more often than they do hearing partners, nearly three-fourths of the married deaf being married to deaf partners.[56] Not only has it been feared that the offspring of such marriages might likewise be deaf, but there has also been apprehension lest in their encouragement there might result a deaf species of the race.[57]

From our discussion, however, we have found that in most of the marriages of the deaf we have but small reason for disquiet. If deafness in the parent is really adventitious, there is little possibility of its passing on to the offspring. When the deafness in the parent is itself congenital, the situation becomes more serious. If in such case there is no added risk from the existence of deaf relatives, the likelihood of transmitting deafness need not always be a matter of deep concern, though the hazard is materially larger than for adventitious deafness. When there are deaf relatives involved, the peril, made stronger if coupled with congenital deafness, is most pronounced; and, indeed, the existence of collateral deafness seems a more certain sign of warning than direct heredity itself. Finally, even in the marriage of the deaf with the hearing, the dangers are not in fact lessened if conditions otherwise unchanged are attendant.

What action should be taken in respect to that part of the deaf who may marry under conditions favorable to the production of deaf offspring is not at present clear. Legislation would not appear on the whole to be advisable;[58] and the exertion of moral suasion, so far as possible, in the individual cases concerned would seem a more acceptable course. The matter, however, really belongs in the province of eugenics, and we will probably do best to await the authoritative pronouncement of its decrees before full procedure is resolved upon.

CONGENITAL DEAFNESS AS AN INCREASING OR DECREASING PHENOMENON

The final matter to be ascertained in respect to congenital deafness is whether it is relatively increasing or decreasing. The following table will show the number of the congenitally deaf in the censuses of 1880, 1890, and 1900, with their respective percentages and the ratios per million of population.[59]

NUMBER OF THE CONGENITALLY DEAF IN 1880, 1890, AND 1900

RATIO PER
TOTAL CONGENITALLY PER MILLION OF
NUMBER DEAF CENT POPULATION

1880 33,878 12,155 35.6 242 1890 40,562 16,866 41.2 269 1900 37,426 12,609 33.7 166

From this it appears that congenital deafness is decreasing both in relation to all deafness, and to the general population.

For further statistics, we may revert to our tables under adventitious deafness. In the tables relating to periods of successive recent years we find in respect to three schools, the New York and Western Pennsylvania institutions and the Maryland School, with certain fluctuations, no great change on the whole, though the last named school shows still a very high proportion. In two schools, the Michigan and Wisconsin, rather an increase is observed. In the Pennsylvania Institution, which covers a period of seventy years, there is a decrease from over 50 per cent to less than 40.

A better test perhaps lies in the comparison of the proportions found for congenital deafness in the tables relating to periods widely separated in time. In these an increase is seen in the single case of the Ohio School; while a decrease is apparent in three, namely, the American and Iowa schools and the New York Institution. These decreases in percentages are respectively from 44.8 and 50.1 to 35.2; from 37.2 to 26.9; and from 42.9 to 38.0.[60]

From the evidence that we have, then, taken together, it seems reasonable to conclude that congenital deafness is, though slowly, becoming less in the course of the years.

CONCLUSIONS WITH RESPECT TO THE ELIMINATION OR PREVENTION OF DEAFNESS

Most of what has been said in this chapter with respect to the elimination or prevention of deafness may be summed up as follows:

1. There are two kinds of deafness--adventitious and congenital. Of the total number of cases adventitious deafness comprises nearly two-thirds, and congenital deafness a little over one-third.

2. Nearly all adventitious deafness is caused by some disease of infancy or childhood attacking the middle or internal ear, a large part being of infectious character. The two chief diseases causing such deafness are scarlet fever and meningitis, with a less amount from brain fever, typhoid fever, measles, catarrh, diphtheria, whooping cough, etc.

3. A considerable part of this deafness is preventable under enlightened action. Medical science is principally in control of the situation, but there is also much that can be done in general measures for the protection of the health. In attacking the problem, the most immediate practical program lies in the arrest of those diseases, especially infantile and infectious diseases, that cause deafness.

4. Our evidence is incomplete to determine definitely whether adventitious deafness is increasing or decreasing relatively among the population; but it is hardly other than likely that it is decreasing. Although certain diseases producing deafness fail to show any extensive signs of abatement, there are other diseases from which there can be little doubt that deafness is decreasing.

5. In the outlook there is, on the whole, promise, both in respect to the treatment of deafness itself and of the diseases that lead to deafness, though it cannot be said in any sense that any large or general relief is at present in sight.

6. Of congenital deafness nearly half occurs in families often without any positively known strain to indicate a predisposition to deafness. Though concerning this deafness little in the present state of our knowledge can be predicated, it is likely that with measures to secure a race sound in all particulars there will be a reduction to a greater or less extent of such deafness.

7. Consanguineous marriages do not take place, so far as deafness as an effect is concerned, to any great extent; though where they do the consequences are very marked. Their relation to deafness consists apparently for the greatest part in the fact that the chances of its transmission are thereby intensified, there being also a very strong connection with the question of deaf relatives in general.

8. There are a certain number of families in society deeply tainted with deafness, in evidence both lineally and collaterally, and this deafness may be transmitted from parent to offspring.

9. Children of deaf parents are far more likely to be deaf than children of hearing parents.

10. The great majority of the children of deaf parents, however, are able to hear, the proportion of those who are not being small.

11. The likelihood of deaf offspring is not necessarily greater when both parents are deaf than when one is deaf and the other hearing.

12. The liability to deaf offspring depends in the greatest degree upon the presence or absence in the parents, deaf or hearing, of deaf relatives, and, to a less extent, upon whether or not the existing deafness is congenital--being especially great under a combination of these two conditions.

13. Action in respect to marriages of the deaf likely to result in deaf offspring seems for the present rather to be limited to moral forces.

14. Congenital deafness appears, from all the evidence, to be decreasing relatively among the population, though probably only at a very slow rate.

15. Finally, with respect to our original inquiry, it is to be said that there are no indications that deafness will disappear from the human race within any time which we can measure; and hence that the deaf are to be in society not only for a season, but for a period apparently as yet indefinite. Nevertheless the situation is not without encouragement. From the data in our possession regarding deafness as a whole, it seems certain that deafness is not on the increase relatively among the population. From our knowledge concerning adventitious deafness, the probabilities are that, if anything, it is decreasing; while the evidence as to congenital deafness is that it is decreasing. It is likely, then, that deafness in general is tending to decrease; and we are thus justified in believing that the number of the deaf will in time become less.

FOOTNOTES:

[15] Moreover, later censuses are probably taken more thoroughly than former, with a consequent discovery of a larger number of the deaf; while at the same time greater care is employed in preparing the later censuses, with the more rigorous elimination of doubtful cases, all in some measure, however, tending to even up the differences. On the difficulty of making comparisons of the censuses of the deaf, see Special Reports, pp. 66-69; _Annals_, li., 1906, p. 487.

[16] _Ibid._

[17] Deafness has also been divided into three classes: adventitious deafness, congenital or hereditary deafness, and infantile or sporadic congenital deafness, the last class including many cases where there are other antecedent defects, mental or physical, or where the deafness occurred shortly after birth with the exact cause not definitely determined. See Proceedings of International Otological Congress, ix., 1913, p. 49; _Volta Review_, xiv., 1912, p. 348; xv., 1913, p. 209.

[18] Of the cases usually ascribed to accidents, as falls, blows and the like, the probabilities are that a large part are really to be attributed to some other cause. Deafness is not often likely to result from such occurrences.

[19] See Proceedings of International Otological Congress, ix., 1913, p. 49; _Volta Review_, xiv., 1912, p. 348.

[20] Special Reports, pp. 110, 122, 124. See also _Annals_, xxxiii., 1888, p. 199; lii., 1907, p. 168. In the table are given only the specified causes that represent at least 0.7 per cent of the total amount of deafness. In respect to external ear trouble, impacted cerumen is usually found to result from water in the ear, or wax in the ear. Other diseases of the middle ear of suppurative character are diphtheria, pneumonia, erysipelas, smallpox, tonsilitis, teething, bronchitis, and consumption. Other non-suppurative diseases of the middle ear are whooping cough, scrofula, exposure and cold, disease of the throat, thickening of eardrum, croup, etc. Of the internal ear, other causes affecting the labyrinth are malformation, noise and concussion, mumps, and syphilis; affecting the nerve, paralysis, convulsions, sunstroke, congestion of brain, and disease of nervous system; and affecting brain center, hydrocephalus and epilepsy. Among unclassified causes are also adduced neuralgia, childbirth, accident, medicine, heat, rheumatism, head-ache, fright or shock, overwork, lightning, diarrhea, chicken-pox, operation, and other causes.

[21] Proceedings of National Conference of Charities and Corrections, 1906, p. 250; Ceremonies of Laying of Corner Stone of Rhode Island School, 1907, p. 27.

[22] There are no general or organized movements on foot for the prevention of deafness as there are for the prevention of blindness. This is perhaps chiefly because there are believed to be nothing like so many preventable cases of the one as of the other, so much of blindness being due to diseases that might have been avoided without great difficulty, and to accidents and other injuries to the eye.

[23] It has been estimated that three-fourths of deafness from primary ear diseases, and one-half from infectious diseases, is preventable. See Proceedings of International Otological Congress, _loc. cit._; _Volta Review_, xiv., 1912, pp. 251, 348.

[24] Proceedings, 1903, p. 1036.

[25] _Volta Review_, xv., 1913, p. 136. See also _ibid._, v., 1903, p. 415; _Outlook_, civ., 1913, p. 997.

[26] See _Medical and Surgical Monitor_, vii., 1904, p. 47; _New York Medical Journal_, lxxxiii., 1906, p. 816; _Annals_, lv., 1910, p. 192; _Volta Review_, xiii., 1911, p. 332.

[27] The possibilities, for instance, in the use of antitoxins and vaccines in certain diseases are just beginning to be known, and some results as affect deafness may be expected from such operations.

[28] In 1909 a special committee in regard to the prevention of deafness was created by the Otological Section of the American Medical Association, and in 1910 both by the American Laryngological, Rhinological and Otological Society and by the American Otological Society. See _Laryngoscope_, xx., 1910, pp. 596-665; _Volta Review_, xii., 1910, pp. 267, 545.

[29] Laws, 1906, ch. 502.

[30] On the possibilities of the prevention of adventitious deafness, see Dr. J. K. Love, "Deaf-Mutism", 1896; Archives of Otology, xxiv., 1895, p. 50; _Journal of American Medical Association_, liii., 1909, p. 89; _New York Medical Journal_, l., 1889, p. 205; lxxxix., 1909, p. 1007; xcv., 1912, p. 1189; _New York State Journal of Medicine_, xii., 1912, p. 690ff.; _Maryland Medical Journal_, lv., 1912, p. 33; _Pediatrics_, xxiv., 1912, p. 335; _Popular Science Monthly_, xlii., 1892, p. 211; "Progress in Amelioration of Certain Forms of Deafness and Impaired Hearing," Proceedings of American Association to Promote the Teaching of Speech to the Deaf, iv., 1894; _Annals_, xxxiv., 1889, p. 199; lvi., 1911, p. 211; lviii., 1913, p. 131; _Volta Review_, xii., 1910, p. 143; xv., 1913, p. 303; New York _Times_, April 6, 1913; Public School Health Bulletin, Eyes and Ears, by Superintendent of Public Instruction of North Carolina, 1910.

[31] Census Reports, 1880. Report on Defective, Dependent and Delinquent Classes of the Population of the United States, 1888, p. 402ff.; Census Reports, 1890. Report on Insane, Feeble-minded, Deaf and Dumb and Blind, 1895, pp. 108ff., 648; Special Reports, 1906, p. 122.

[32] _Ibid._

[33] Probably with the "fevers" the proportion would be larger.

[34] Less than 0.7 per cent.

[35] Probably included with certain of the suppurative diseases.

[36] Not a large number of schools, it is greatly to be regretted, give, regularly and over an extended period of time, such information in statistical form and upon the same basis from year to year.

[37] Total attendance.

[38] These tables are based upon statistics given in the reports of the schools, and given in _Annals_, vi., 1854, p. 237; xv., 1870, p. 113; xvii., 1872, p. 167.

[39] One case reported.

[40] Letters of inquiry as to whether or not "total" deafness appeared to be decreasing were sent by the writer to the professors of diseases of the ear of the medical schools of Johns Hopkins University, University of Pennsylvania, Columbia University, Cornell University, Harvard University, University of Chicago, Northwestern University, University of Michigan, and the Jefferson Medical College of Philadelphia. The opinion of four of these is that such deafness is clearly decreasing; of three that little or no decrease is apparent; while by two no opinion can be vouched yet. The greatest encouragement is found in respect to treatment for middle ear affections and infections from fevers. By Dr. S. MacCuen Smith, of the Jefferson Medical College, it is believed that there is a decrease, "largely due to the fact that not only the general medical profession, but the public at large, are recognizing the importance of having the minor aural lesions promptly and properly cared for. This being the case, it is no longer possible for children in the public schools to continue their studies when suffering from diseased tonsils and enlarged adenoid vegetations. From this cause alone, many cases of impairment of hearing which usually occur later in life will be prevented in the future". By Dr. E. A. Crockett, of Harvard University, it is believed that, although there is a larger amount of deafness from measles, there is less, not only from scarlet fever, but also from chronic suppurations, from adenoid and throat troubles in general, and even from meningitis, owing to the use of serums. Regarding his own observations, within a period of twenty-five years "the number of extremely deaf persons and deaf-mutes has very materially diminished".

[41] Hereditary deafness is sometimes of a kind that manifests itself some years after birth, often with certain relatives similarly affected. This is especially true of catarrhal and middle ear affections, though their results may more often be partial rather than total deafness.

[42] In a part of such deafness, and also in a portion of that occurring shortly after birth, the cause is said to be syphilis. See Proceedings of International Otological Congress, ix., 1913, p. 49; _Volta Review_, xiv., 1912, p. 348; xv., 1913, p. 209.

[43] Special Reports, pp. 125, 236. There were 3,341 who failed to answer, and if all had made reply, our percentage would probably be higher yet.

[44] P. 108.

[45] In the Louisiana School 10 per cent of the pupils are said to have parents who were blood relatives; in the Illinois, 5 per cent; and in the Kansas, from 5 to 5.5 per cent. Report of Louisiana School, 1906, p. 17. See also Transactions of American Medical Association, xi., 1858, pp. 321-425; Proceedings of Conference of Principals, iii., 1876, p. 204; _Annals_, xxii., 1877, p. 242.

[46] On this subject, see Francis Galton. "Natural Inheritance", 1889, p. 132ff. See also G. B. L. Arner, "Consanguineous Marriages", 1908, p. 65ff.; C. B. Davenport, "Heredity in Relation to Eugenics", 1911, p. 124ff.

[47] Special Reports, pp. 128, 235, and _passim_.

[48] These proportions are further indicated in the succeeding section.

[49] Special Reports, p. 135ff.

[50] Report, 1908, p. 31.

[51] Out of 107 children born to former pupils of the Minnesota School up to 1892, 2, or 1.9 per cent, were deaf. Report, 1892, p. 39. Out of 811 children born to former pupils of the American School up to 1891, 105, or 12.9 per cent, were deaf. Report, 1891, p. 20.

[52] The study had been originally planned by Dr. F. H. Wines for the _International Record of Charities and Corrections_. See issue for October, 1888. The work was published by the Volta Bureau. For a discussion of the results, see _Association Review_, ii., 1900, p. 178; Publications of American Statistical Association, vi., 1899, p. 353; _Biometrika_ (London), iv., 1904-5, p. 465. See also charts in current numbers of _Volta Review_.

[53] From the total number of marriages, 974 were deducted, being cases concerning the offspring of which no information could be obtained, and also 434 cases where there were no offspring.

[54] From p. 134. It has also been computed by Dr. Fay from his data that of 5,455 married deaf persons, 300, or 5.5 per cent, have deaf offspring. _Annals_, lii., 1907, p. 253.

[55] The proportions for the general population are hardly over 0.3 per cent and 0.05 per cent respectively.

[56] The proportion of the married deaf who are married to deaf partners is found by Dr. Fay to be 72.5 per cent, and of those married to hearing partners, 20 per cent, there being no information for the remaining 7.5 per cent. The census returns, however, give the respective proportions as 51.3 per cent and 48.7 per cent.

[57] See Proceedings of National Conference of Charities and Corrections, 1879, p. 214; A. G. Bell, "The Formation of a Deaf Variety of the Human Race", Memoirs, 1883, ii., part 4, p. 177; Proceedings of Conference of Principals, i., 1868, p. 91; v., 1884, p. 205; A. G. Bell, "Marriage, an Address to the Deaf", 1898; Evidence before the Royal Commission on the Deaf, etc., 1892, ii., pp. 74-129; _Annals_, xxix., 1884, pp. 32, 72; xxx., 1885, p. 155; xxxiii., 1888, pp. 37, 206; _Popular Science Monthly_, xvii., 1885, p. 15; _Science_, Aug., 1890, to March, 1891 (xvi., xvii.); _Arena_, xii., 1895, p. 130; _Association Review_, x., 1908, p. 166; _Volta Review_, xiv., 1912, p. 184; Proceedings of Reunion of Alumni of Wisconsin School for the Deaf, vi., 1891, p. 46; National Association of the Deaf, iv., 1893, p. 112; ix., 1910, p. 69; Report of Board of Charities of New York, 1911, i., p. 150.

[58] No statutory action seems ever to have been taken in the matter. In Connecticut, however, in 1895 when a law (Laws, ch. 325) was enacted forbidding the marriage of the feeble-minded and epileptic, a provision respecting the congenitally deaf and blind came near being included. _Annals_, xl., 1895, p. 310.

[59] Census Reports, 1880. Report on Defective, Dependent and Delinquent Classes of the Population of the United States, 1888, p. 402ff.; Census Reports, 1890. Report on Insane, Feeble-minded, Deaf and Dumb and Blind, 1895, pp. 108ff., 684; Special Reports, 1906, p. 122. The ages of the deaf were reported less fully in 1880 than in 1890, and less fully in 1890 than in 1900; and if we take the numbers of those whose ages were reported in these three censuses, we have the following table, showing the proportion of the congenitally deaf.

THE CONGENITALLY DEAF ACCORDING TO NUMBERS IN WHICH AGE WAS REPORTED

NUMBER
WHOSE AGE CONGENITALLY PER
WAS REPORTED DEAF CENT

1880 22,473 12,155 54.7 1890 37,204 16,866 45.8 1900 35,479 12,609 35.3

If we assume that the proportion of the congenitally deaf to all the deaf in each census was the same that it was among the cases in which the age of the occurrence of deafness was reported, we have this table to show the number of the congenitally deaf and the ratio of the deaf among the population.

THE CONGENITALLY DEAF ACCORDING TO NUMBERS ASSUMED

ASSUMED
NUMBER OF RATIO PER
CONGENITALLY MILLION OF
DEAF POPULATION

1880 18,531 369 1890 18,375 293 1900 13,286 175

These tables are taken from _Annals_, li., 1906, p. 487.

[60] In the three schools where an increase in congenital deafness appears to be found, namely, those of Michigan, Wisconsin and Ohio, a partial explanation probably lies in the fact that in these states a number of day schools have been created of late years, which are not likely to draw congenitally deaf pupils to the extent that the institutions do, thus leaving a larger proportion for the latter. See also E. A. Fay, _op. cit._, p. 125.