INSTINCTS AND HABITS IN CHICKS 69 



brightness values of the stimuli? After black-blue training the 

 chicks quite commonly rejected this blue no matter with what 

 other color it was in combination. It may be suggested that 

 after the long period of training the chicks respond to a par- 

 ticular brightness value, the blue amounting to a certain degree 

 of gray. But no. 32 and no. ^t, rejected blue (tint no. i) when 

 it was used in combination with the much brighter yellow. 



The method of training with the electric shock frequently 

 makes the stimulus to which it is attached the emphatic one. 

 In a word, the chicks thus trained may not be guided in their 

 reactions by the color through which they escape, but by the 

 color in connection with which they are shocked. This reaction 

 is one primarily of rejecting blue, rather than of accepting black. 

 It is indicated by such reactions as those of nos. 32, ^t,, and 39 

 to black-white after having been trained to black-blue. When 

 white replaced the blue of the original training combination, 

 the stimuli became almost indifferent to the chicks. Again, the 

 same chicks seemed indifferent to the color presented with blue. 

 When required to react to blue-white there was no hesitancy, 

 the response being one of getting-away-from-the-blue-no-mat- 

 ter-what-the-other-color. For data see table 24. 



All the chicks did not behave so, however. A comparison of 

 the corresponding reactions of nos. 17, 18, and 20 is instructive. 

 These animals, when white replaced blue as above, responded 

 definitely and positively to black, and were quite lost when 

 white accompanied blue. With these chicks black seemed to 

 be the guiding stimulus. 



It is sometimes said that negation is affirmation, but is this 

 true in any proper psychological sense? Naturally, avoidance 

 of one object means the acceptance of some other object — in 

 the sense that leaving one place means going somewhere else. 

 But does the " somewhere else " need to be defined as a con- 

 stituent element of the avoiding reaction? Or, upon the occur- 

 rence of a positive response, is it necessary to consider the point 

 of departure, which is objectively definable, of course, as a part 

 of the process ? The point of departure in the latter or of arrival 

 in the former case does not appear to be essential. 



Passing now from the standpoint of stimulus to that of reac- 

 tion, why should a positive response be regarded as a simul- 

 taneous negative response? As antagonists may they not mutu- 



