56 G. V. HAMILTON 



B to C, from which point it ascends to D; from D it ascends 

 very sharply to E, where it attains its maximum height 



(12) The horse's curve is near the base line until it reaches 

 C, from which it ascends sharply to D; from D it makes a still 

 sharper ascent to E, the point of its maximum height. 



V. INTERPRETATIONS OF RESULTS. CONCLUSIONS. 



It has been shown, I believe, that the higher mammals man- 

 ifest striking differences of modes of trial and error activity, 

 and that these differences cannot be adequately expressed 

 in terms of rapidity of habit formation alone. The results 

 indicate, also, the need of intensive behavior-studies along 

 hitherto unexplored lines of investigation. The present chapter 

 seeks to relate the types of reaction that have been discussed in the 

 foregoing to inferred reactive tendencies, and thus to assign 

 psychological values to the curves of distribution shown in 

 figure 3. This attempt must be prefaced, however, by a 

 statement of the viewpoints from which the interpretations that 

 follow have been undertaken. 



While the Comparative Psychologist has been almost exclu- 

 sively concerned with a single psychological value — associative 

 memory* — the field of Psychopathology has been revolutionized 

 by a group of men who have shown that behavior is determined 

 by a vast complexus of reactive tendencies which demand isola- 

 tion and psychological estimation. These men, notably Freud 

 (6), Jung (7), Bleuler (8), and Adolph Meyer (9), have opened 

 up, by their activities along highly specialized lines of interest, 

 new possibilities for the development of genetic psychology. 

 They have shown, by implication, at least, that genetic psychol- 

 ogy should not be solely concerned with the developmental 

 history of the specifically adaptive instincts and of the mature 

 human ability to think according to the traditional canons of 

 logic. The dancing mouse's acquisition of a habit of selecting 

 a spatially variable white labelled avenue of escape from pain, 

 and the mathematician's solution of a problem in infinitesimal 

 calculus are alike to be looked upon as end-products of reactive 

 tendencies which have been variously subjected to the selective, 

 suppressive, fixative and other corrective influences of experi- 



' The writer assumes that functional* studies of the sense organs belong to Physi- 

 ology rather than to Psychology. 



