528 W. T. JAMES 



somes significantly different, but did find the athletosomes 

 and leptosomes, classified together by Kretschmer, to be quite 

 dissimilar. Cabot then studied the subjects which showed 

 the widest physical differences and concluded that the athletic 

 type had a distinct advantage in social adjustment. From 

 this he postulates a theory of socio-biological advantage in 

 terms of which socio-sthenic traits, or personality charac- 

 teristics, are associated with a biologically good physique. 

 In other words, as far as the personality traits investigated 

 are concerned, those subjects with the best physiques were 

 judged as having definite advantages over other members 

 of a group. 



All writers agree that there are differences among indi- 

 viduals, but there is great confusion as to the nature of 

 these differences and how to determine them. The human 

 subject is too complicated, too mixed genetically, and in- 

 volves too many factors beyond control to be used in an 

 analysis of the bases of such differences. Offering more 

 promise of an understanding of the problem would be a 

 study of psychological variations among animals, especially 

 if the particular animal to be studied offered wide differences 

 in both physique and behavior. The interdependence of mor- 

 phological, neurophysiological, and psychological factors can 

 be specifically determined only by experimental treatment 

 and genetic control of the individual. 



Since a good deal is known about the morphological and 

 endocrinological side of constitution in the dog, it would be 

 of special interest to investigate the psychological aspect. 

 In this way, we may be able to isolate the significant organ- 

 ismal factor for psychological differentiation of types among 

 the human, or at least to arrive at some understanding of 

 the difficulties found in analyzing them. 



Throughout the earlier sections of this book, references 

 have been made to the general behavior differences among 

 dogs. Close observation will contrast the active nature and 

 overt movements of the German shepherd and Saluki with 

 the inactive and sluggish nature of the bassethound. The 



