52 G. V. HAMILTON 



to render it easy for the reader to tell at a glance the type of 

 reaction most frequently manifested by any subject. 



The older normal human subjects and defective Boy A are 

 seen to have " preferred " Type A reaction. Defective Man A 

 preferred Type B, and the infant Boy i preferred Type E. 



The mature monkeys and one of the immature monkeys 

 (No. 4) have their highest percentages in the Type D column, 

 whilst immature Monkeys 2 and i have their highest percen- 

 tages in Type C and Type B columns respectively. In view of 

 the fact that reactions of Types B and C are more adequate 

 modes of adjustment than is the Type D reaction, this finding 

 is of considerable interest, as will be show^n in the next chapter, 

 where a psychological interpretation of these types of reaction 

 is attempted. 



Of the twenty -two animal subjects below the primates, only 

 five preferred any other type of reaction to Type E. These 

 exceptional cases require the following explanation. Dogs 2 

 and 3F1 were obviously more intelligent in meeting the situa- 

 tions of everyday life than were their fellows. Dogs 5F2 and 

 iiFi, who manifested a preference for Type C reactions, seem 

 to have fixed upon this systematic mode of searching for the 

 unlocked door much earlier in the experiment than is usually 

 the case with dogs: after a variable number of trials (usually 

 from 300 to 600) the average dog will manifest 100 per cent 

 of Type C reactions. 



Cat I, who manifested a preference for Type B reactions, 

 has already been described as an exceptionally intelligent animal 



(P- 43)- 

 The evidences of marked individual differences contained in 



table 4 must be looked upon, of course, as a serious obstacle 



to any effort to deal with the results in terms of age and phyletic 



averages. It is obvious that such averages, to be available 



for conclusive interpretations, would have to be obtained from 



a far greater number of subjects for experiment than could 



be practically used in an exploratory investigation. However, 



since the averages obtainable from the above table may serve 



to attract attention to some interesting possibilities in genetic 



psychology, the writer is justified, I believe, in presenting them. 



