NATURE 



97 



THURSDAY, NOVEMBER 30, 1899. 



THE INHERITANCE OF DEAFNESS. 



Marriages of the Deaf in America. By Edward Allen 

 Fay. Pp. 527. (Washington : The Volta Bureau? 

 1898.) 



MR. FAY'S work is an inquiry concerning the results 

 of marriages of the deaf in America, a research 

 originally instituted by Dr. A. Graham Bell among the 

 charges which he committed to the Volta Bureau when 

 he endowed that institution. When Mr. Fay under- 

 took this work— as a labour of love — the resources of the 

 Bureau were placed at his disposal, and he was further 

 helped in his investigations by his Government appoint- 

 ment as a special agent for the collection of statistics re- 

 lating to the deaf of the United States during the taking 

 of the eleventh census. By these means Mr. Fay was 

 particularly well equipped for his work, and the volume 

 before us is no mean result. Taking as the chief aims of 

 his inquiry the solution of certain questions of interest 

 and importance to the deaf as a class and as individuals, 

 he has sought by all the means in his power to obtain 

 satisfactory replies, and his success will be seen by all 

 who care to give the book a careful study. The ques- 

 tions to be elucidated were as follows : — 



(i) Are marriages of deaf persons more liable to 

 result in deaf offspring than ordinary marriages ? 



(2) Are marriages in which both of the partners are 

 deaf more liable to result in deaf offspring than marriages 

 in which one of the partners is deaf and the other is a 

 hearing person ? 



(3) Are certain classes of the deaf, however they may 

 marry, more liable than others to have deaf children ? 

 If so, how are these classes respectively composed, and 

 what are the conditions that increase or diminish this 

 liability? 



(4) Aside from the question of the liability of the 

 offspring to deafness, are marriages in which both of the 

 partners are deaf more likely to result happily than 

 marriages in which one of the partners is deaf and the 

 other a hearing person ? 



These are questions which have been submitted to con- 

 siderable discussion both in Europe and America, with 

 the result that the conclusions arrived at have differed 

 widely. Indeed the conclusions have ranged between 

 the dictum of Graham' Bell, that " the evidence shows a 

 tendency to the formation of a deaf variety of the human 

 race in America," on the one hand, to that of the 

 Commissioners of the Irish census of 1881, that "it 

 appears evident that the question of deafness and 

 dumbness in parents has no influence in propagating 

 the defect." 



Mr. Fay's inquiry commenced in 1889, and the work 

 has continued uninterruptedly since that time. Exhaus- 

 tive questions were sent out and about, and the replies 

 received were both more numerous and more complete 

 than was anticipated. 



It would be beyond the purpose or scope of this review 



to enter with any detail into the large number of statistics 



placed before Mr. Fay's readers ; suffice it to say that 



they bear the stamp of having been most carefully 



NO. 1570, VOL. 61] 



collected, tested, and arranged, and may therefore be 

 taken as more trustworthy tljan statistics are usually found 

 to be. In the tabular statement of marriages details are 

 given of no less than 4471 unions— a fact that will give 

 the reader some idea of the onerous nature of Mr. Fay's 

 task. 



It appears that marriages of the deaf are more common 

 in America than in Europe, and they have increased at a 

 high rate of progression during the present century. 

 From the statistics it appears that marriages of deaf 

 persons, one or both of the partners being deaf, are far 

 more liable to result in deaf offspring than ordinary 

 marriages. The proportion of deaf marriages resulting 

 in deaf offspring is 97 per cent., and the proportion of 

 deaf children born therefrom is 8'6 per cent. Accurate 

 data as to the proportion of deaf children born of 

 ordinary marriages are not easily obtainable, but that 

 proportion is probably less than rio per cent. On the 

 other hand, marriages of the deaf are far more likely to 

 result in hearing offspring, the proportion of hearing 

 children being 75 per cent. 



These results are in accordance with the two laws of 

 heredity: (i) that a physical anomaly tends to be 

 transmitted to the offspring, and (2) that offspring tend 

 to revert to the normal type. 



There is a greater liability to deaf offspring of mar- 

 riages of the congenitally deaf, since congenital or 

 innate characteristics are far more likely to be trans 

 mitted than are acquired characteristics. 



It appears also that deaf persons having deaf relatives^ 

 however they are married, and hearing persons having 

 deaf relatives and married to deaf partners, are very 

 liable to have deaf offspring. Finally, the marriages of 

 the deaf most liable to result in deaf children are those 

 in which the partners are related by consanguinity. 



The most important statistics (summed up in a separate 

 table) are those showing the number of marriages of 

 each class of which the results are reported and the 

 number and percentage of each class resulting in deaf 

 children, with the number of children born from mar- 

 riages of each class, and giving the number and per- 

 centage of those deaf. These statistics show the com- 

 parative liability to deaf offspring of the several classes 

 of marriages. 



As regards the happiness of deaf unions, marriages in 

 which both parties are deaf appear to be more likely, 

 other things being equal, to result happily than those in 

 which one of the partners is deaf and the other possesses 

 normal hearing ; the proportion of divorces and separ- 

 ations in the former class being 2"5 per cent., in the 

 latter 6'4 per cent. This is easily explainable on the 

 grounds of mutual fellowship and identity of social rela- 

 tions and sympathies which arise from the union of indi- 

 viduals suffering from similar conditions. 



An appendix is devoted to illegitimate unions, but the 

 totals of their statistics are too small to furnish any 

 certain basis for trustworthy conclusions. 



Mr. Fay has produced a valuable work, and one which 

 should take a prominent place in the literature — neces- 

 sarily not a very large one— of the subject. From a 

 careful perusal one cannot fail to note the clearness of 

 his statements and the logical way in which he works 



