INFLUENCE OF HEREDITY IN STAMMERING 



Frank A. Bryant, M.D. 

 New York, N. Y. 



STAMMERING or stuttering; (I use 

 the terms synoiiomously, for most 

 Enf^lish speaking authorities agree 

 that stuttering is a form of stammering) 

 is one of those traits which is diffi- 

 cult to classify as either wholly men- 

 tal or wholly physical. At first sight 

 it would appear to be a physical 

 defect, but closer study shows that 

 this view is not tenal)le. It is not 

 an organic trouble, but a functional 

 one, as is proved by its intermittent 

 manifestations, which point also to its 

 purely nervous or mental origin. It is 

 ordinarily due to a morbid irregularity 

 or interruption of the normal functions 

 of the mind in its relation to speech. 



This is not an argument against its 

 transmissibility, however, for the child 

 inherits his brain from his parents just 

 as much as he does any other part of 

 the body. The inheritance of various 

 mental disorders is as firmly established 

 as is any fact in biology. There is a 

 priori, then, no reason to suppose that 

 a tendency to stammer might not be 

 inherited; to determine whether or not 

 it actually is inherited, we must ap])eal 

 to the evidence. 



STUDY OF 20,000 CASES 



In a practice of over thirty-five years, 

 I have come in contact with more than 

 20,000 persons afilicted with stammer- 

 ing in its various forms. According to 

 mv observations and statistics, at least 

 half of these 20,000 stammerers had 

 relatives who at one period or another 

 in their lives suffered from one form or 

 another of nervous speech disorder. 



In the early stages of the stammering 

 of very young children, it begins 

 spontaneously, seemingly without any 

 external cause, upon the very first at- 

 tempts to speak. While some cases 

 do not show the afTection until after the 

 third or fourth year, I have never known 

 an instance where it began with the 



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early attempts at speech unless some 

 blood relatix'e had previously shown 

 disordered utterance. 



This early manifestation of the trouble 

 precludes absolutely the assumption 

 that it is a habit or the result of faulty 

 education, example or enx-ironment. 

 because the cliild on account of its 

 extreme youth had never been brought 

 under such influences. 



My statistics show that the number of 

 stammerers with relatives who have 

 stammered is greater than the number 

 of stammerers from all other causes put 

 together. This furnishes a strong pre- 

 sum])tion of inheritance, which is con- 

 verted into absolute proof by a study of 

 the nature of some of these cases of 

 relationship. It is a fact that grand- 

 children frequently stammer who have 

 never seen the grandfather or grand- 

 mother who stammered. The speech 

 of the nephews and nieces of an affected 

 person is likewise impaired; and cousins 

 who have never seen each other fre- 

 quentlv stammer. Such crucial in- 

 stances ofTer the best evidence possible 

 of real inheritance. 



Many cases of what might be called 

 atavism have come under my observa- 

 tion. I mean cases of stammering 

 which seem to have skipped one or 

 more generations. The following des- 

 cription of what occurred in one family 

 of my practice will illustrate the point. 



A man who lived to be 80 years of age 

 was a stammerer from childhood. It 

 could not l)e ascertained whether any of his 

 relatives had ever been afflicted in this 

 way. He had two sons, Robert and 

 Henry. Robert, the elder son, showed 

 stammering in his first attempts to talk. 

 He grew to manhood a stammerer, married 

 and had two or three children, neither of 

 whom was afflicted with speech trouble. 



One of these children, William by name, 

 also had two children, a boy and a girl, 

 both of wliom stammered quite severely 

 from no apjiarent cause from the tirne 

 when they first began to speak. This 

 was in the fourth generation from the 



