From these few cases of actual occurrences, it will be seen that practically all cases of stammering caused by injury can be traced to the NERVOUS SHOCK brought about by the injury.
HEREDITY AS A CAUSE: There is little that need be said on the subject of heredity as a cause of stuttering and stammering, save that heredity is a common cause and that children of stuttering or stammering parents usually stammer. In this, as in the case of any malady hereditarily transmitted, it is difficult to say whether the trouble is caused by inheritance or by constant and intimate association of the child with his parents during the period of early speech development.
THE RESULT OF DISEASE: Many cases of both stammering and stuttering may be traced back to disease as the basic or predisposing cause. Acute Chorea (St. Vitus Dance) is frequently the cause of stuttering of a type known as Choreatic Stuttering or "Tic Speech." Infantile Cerebral Palsy sometimes brings about a condition known as "Spastic Speech," while whooping cough, scarlet fever, measles, meningitis, infantile paralysis, scrofula and rickets are sometimes responsible for the disorder.
Disease may cause stuttering or stammering as an immediate after effect or the speech trouble may not show up for considerable time, depending altogether upon the individual. But regardless of the length of time elapsing between the disease which predisposes the individual to the speech disorder and the time of the first evidence of its presence, diagnosis reveals but an insignificant percentage of organic defects in these cases resulting from disease, indicating that even here the predominant causative factor is a mental one.
CHAPTER III
THE PECULIARITIES OF STUTTERING AND STAMMERING
Each individual case of stuttering or stammering has its own peculiarities, already more or less developed—arising from structural differences (but not necessarily defects) in the organs of speech, as well as differences in temperament, health and nervousness; or peculiarities arising from habit—which is the result of previous training or neglect, as the case may be.
SING WITHOUT DIFFICULTY: Almost without exception, the stutterer or stammerer can sing without any difficulty, can talk to animals without stuttering or stammering, can talk when alone and in some cases can talk perfectly in a whisper. Some stammerers have less difficulty in talking to strangers than in talking to friends or relatives while in other cases, the condition is exactly reversed. A stutterer or stammerer almost always experiences difficulty in speaking over the telephone. One experimenter has shown, however, that a stammerer can talk perfectly over the telephone so long as the receiver hook is depressed and there is no connection with another person at the other end of the line. This experimenter shows that immediately the receiver hook is released and a connection is established, the halting, stumbling utterance begins.
These peculiarities of stuttering and stammering for many years puzzled investigators and were, in fact, finally responsible for arriving at the true cause of stammering.