BIOLOGY IN HUMAN AFFAIRS 



the term X-Y traits, indicating that the behavior trait, 

 as we find it, is a compound composed of two elements 

 combined in unknown proportions — X representing origi- 

 nal nature, and Y representing the factor of nurture. 



The scientifically minded psychologist naturally regrets 

 that the relative contributions of these two factors cannot 

 at present be precisely delimited; but for the practical 

 purposes of education this is not so important. What is 

 important for the educator is to know what X-Y traits 

 are present in children when they present themselves in 

 the schools, and how best these traits can be used in the 

 process of moulding children according to the patterns 

 furnished by the social ideals. Just what traits shall be 

 included in such an X-Y list will depend upon where the 

 line is to be drawn with respect to the amount of saturation 

 with the X element before the trait is so classed. In one 

 sense, every trait the child exhibits is an X-Y trait. It 

 always contains some element of original nature and some 

 elements that have been contributed by experience. Limi- 

 tation of the number to one, such as the Freudian sex 

 motif or Adler's will-to-mastery, ignores a large part of 

 the total realm of human behavior. To extend the list to 

 include only anger, fear, and love, as does Watson, also 

 fails to do justice to the richness of human nature. I for- 

 bear to add a list of my own, but would refer the reader to 

 the lists of James, McDougall, and Thorndike as repre- 

 senting what I regard as, on the whole, reasonably satis- 

 factory inventories. 



In order to deal wisely with human nature in its forma- 

 tive period, the educator must take account of the natural 

 tendencies of human nature to fear, anger, pugnacity, 

 disgust, curiosity, self-assertion and self-display, self- 

 abasement, sex love, sympathy, tenderness, gregariousness, 

 imitativeness, suggestibility, play, jealousy, and other 

 types of behavior. There is no need to decide in the case 



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