164 THE GROWTH OF GROUPS 



discussion. The term embraces a large part of congenital 

 mental disorder. 



The present writer has little practical knowledge of 

 Dementia pr&cox, but it is permissible to mention some 

 of its principal features, as described in any standard 

 work on psychiatry. 



Victims of the disorder are usually regarded as normal 

 until they reach early adult life, when certain eccentricities 

 gradually appear in them. One writer mentions a parent 

 who said, in describing its onset in her daughter, that she 

 grew to be " more and more herself," a descriptive and 

 significant statement which might be applied to other 

 types of eccentricity, such as pass for normal. 



Dementia prcecox is peculiar among diseases in that it 

 appears in the afflicted person when he or she has reached 

 a certain age. There is a definite " age of onset," just as 

 there is an age of onset for the full development of the 

 third molar teeth and also perhaps for the development of 

 what may be called normal mental maturity. In each case 

 the particular attribute is more likely to appear at a 

 certain age in early adult life than at any other age, and 

 is less and less likely to appear as age increases. For 

 example, most afflicted individuals become so at about 

 the age of twenty, fewer at twenty-five, fewer still at 

 thirty, and so on. Kraepelin has shown that this is true 

 of the onset of Dementia prcecox. It is doubtless true 

 of the development of the third molar teeth, perhaps 

 also it is true of the development of normal mental 

 attributes. It seems that demented persons become en- 

 dowed with their peculiarity in place of normal mental 

 maturity. 



The signs of Dementia pracox need not be referred to 



