484 SECTIONAL TRANSACTIONS.— H, I, J. 



magic circle about the earliest settlement, putting and keeping in fertility and 

 warding off the quasi-supernatural harm feared from wolves. A few 

 methodological conclusions. 



SECTION I.— PHYSIOLOGY. 



Owing to the coincidence of the International Physiological Congress 

 (Zurich, August 14-19, 1938), no separate meetings were arranged for 

 Section I (Physiology). 



SECTION J.— PSYCHOLOGY. 



Thursday, August 18. 



Dr. L. S. Penrose. — Heredity and mental hygiene (lo.o). 



A knowledge of the hereditary factors which are partly or wholly 

 responsible for mental diseases can be of preventive value in two ways : 

 firstly, by making it possible to avoid the births of mentally abnormal 

 people and, secondly, by facilitating early and accurate diagnosis so that 

 effective treatment can be applied. Both these methods for controlling 

 mental disease are at present in their infancy because of the lack of precise 

 knowledge in the field of human genetics. The only relevant certainties 

 are the modes of inheritance of some rare mental diseases and defects. Of 

 the more common mental abnormalities, only genetic outlines are known. 

 Some mental defects are recessively determined and also some psychoses 

 with onset early in life : the less severe types of defect and some psychoses 

 with later onset are dominant. A few severe conditions are nearly always 

 sporadic and in some the age of the mother is a determining factor. The 

 biological viewpoint helps in the understanding of nature's own methods 

 of mental hygiene. Though natural selection helps to control the incidence 

 of mental diseases with onset early in life, it has little effect upon the 

 incidence of abnormalities which are not manifested until the end of the 

 period of reproduction. 



Prof. G. Humphrey. — The problem of the direction of thought (10.45). 



Prof. C. W. Valentine. — Facts and fallacies in the social psychology of 

 early childhood (11.30). 



I. It is much harder to ensure exact knowledge about the social develop- 

 ment of children, than about their intellectual abilities. Generalisations 

 are often based on inadequate evidence — sometimes on occasional 

 coincidences. 



Highly speculative inteipretations of the behaviour of a few abnormal 

 children are apt to be accepted partly because they are so original and 

 interesting. 



Examples of such fallacies, in reference to : {a) early sex developments 

 and interests ; {b) thumb-sucking ; (c) early signs of later neuroses ; {d) in- 

 terpretation of some kinds of play in infancy. 



