44 Aubrey Lewis 



a siniile more ruiulanieiital factor which manilcsts itsclt' in 

 them; similarly we measure traits such as perseveration or 

 persistence, which represent an abstraction from several forms 

 of conduct or test response that evidently have a common 

 factor. To determine whether personality changes with 

 advancing- a^e, and how it does so, the surface manifestations 

 of attitude and interest have to be distinouished from the 

 underlyino common factors which make up the basic per- 

 sonality. As far as I know systematic studies of age changes 

 have been almost entirely concerned with the former: no one 

 has applied to the findings the methods of statistical analysis 

 which would reveal whether there are changes in the common 

 underlying characteristics or in the way in which they are or- 

 ganized. It is perhaps a vice in this predominantly statistical 

 approach to the problems of personality that it treats the 

 cross-section of attitudes and test results at a given moment 

 as a constitutional attribute almost immune from time and 

 change: yet there is no inherent reason for this except the 

 great practical dilliculty of large-scale retesting of the same 

 I)opuIation, or of another population strictly comparable in 

 all relevant resj)ccts except age. 



Many of our assumptions about normal personality changes 

 in older people are influenced by the features which mental 

 disorder wears in them. Psychiatrists in particular often 

 allow their experience of paranoid and hypochondriacal 

 trends in senile psychoses to bias their opinion about the 

 normal changes of personality in old age. This is understand- 

 able, since most psychiatrists accept the postulate that mental 

 ilhiesses not accompanied by constant demonstrable tissue 

 changes — the "functional" psychoses — express characteristics 

 of })ersonahty writ large. But do the mental disorders of the 

 elderly in fact exhibit features peculiar to this stage of life? 



It is in "involutional melanchoha" that this (jucstion has 

 been most obviously disputed, backwards and forwards, for 

 the last lifty years. The characteristics said to be typical of 

 these dei)ressi()ns oi' later life are: hysterical symptoms; hypo- 

 chondriacal and paranoid ideas; extreme fear and agitation; 



