52 General Discussion 



who collect snails, and the longevity of amateur naturalists — T don't 

 offer this as statistically significant — docs appear to be quite ])heno- 

 luenal. I ^^ as wondering how far we had any direct proof that going on 

 with the job which an old man can do and which leads him to be 

 reasonably respected and keeps him busy and so on, is in fact a means 

 of maintaining general health, because I get the impression that it 

 probably is. 



Lewis: This is commonly assumed and I shoidd think there is a good 

 deal of evidence of the kind that Dr. Comfort has brought forward. 

 Karl Pearson of course was much interested in this matter, but the 

 difficulty always is, that if you take people like snail experts or judges of 

 the High Court or bishops, you're dealing with people who have perhaps 

 lived lives immune from many of the stresses which in manual labourers 

 affect their health and therefore their duration of life. 



Comfort: The naturalists are a surprisingly varied gToup, as a matter 

 of fact, for they are nearly all amateurs; there are few manual labourers, 

 but there are one or two among them. 



Freeman: Is it your point. Prof. Lewis, that the more intellectual 

 individual declines at about the same rate as the less intellectual? That 

 is, that the percentage decline may possibly be greater but the actual 

 decline may be about the same? 



Lewis: I don't know, and I don't think the evidence warrants any 

 firm statement. 



Olbrich: Do you notice any difference between the two groups, 

 labourers on one side and intellectual workers on the other side, as to 

 the amount of senile dementia? 



Lewis: There is no evidence that I know of, from comparable matched 

 groups. 



Shock: It seems to me that the lack of close correlation between 

 physiological state and mental performance or capacity is probably one 

 of the greatest potential strengths in the entire field of gerontology. 

 The concept that has been put forward that the ageing process sets in 

 and becomes accentuated when the growth process stops has some 

 analogies to mental performance as well. I think we already know some 

 of the things that can continue mental growth in the face of certain of 

 the physiological decrements that often appear with advancing age. 

 Although we do not know as yet how to prevent the physiological 

 changes, we can do something about keeping ageing people mentally 

 active. The low correlation between physiological and psychological 

 measurements, which have plagued us in the past, may be our greatest 

 hope for the future. 



GENERAL DISCUSSION 



Tunbridge: Can we begin with a cellular approach? Is there an age 

 aspect of the cell? 



Aub: This group ought to reach some conclusion about ageing in the 

 cell. Dr. Cowdry said there are cytological tests for ageing. There are 

 good pathologists here, and I'd like to know whether they can tell 



