572 W. T. JAMES 



the end result would undoubtedly show wider differences 

 than is the case in these experiments, in which an attempt 

 is made to determine to some extent the course of action. 

 The difference is not only one of energy but organization of 

 neural processes as well. 



The intermediate types are not dominantly lethargic or 

 excitable. They are never too excited to enter into the per- 

 formance, nor so sluggish as to lose all interest in the experi- 

 ments ; throughout the training, they remain active and moti- 

 vated and are well able to restrain and adjust themselves. 

 They are thus excellent subjects for general experiments in 

 the salivary situation. The animals of the A-plus and B-minus 

 groups are better balanced and more capable of making a 

 wider variety of reactions in any situation than are the ani- 

 mals of either the A or B groups. 



Pavlov also recognized two extreme behavioral types among 

 dogs, with intermediates ranging between them. One of the 

 extremes was considered highly excitable, while the other was 

 inhibited and restrained. The intermediate dogs were con- 

 sidered better balanced, capable of making adjustments to 

 a wider variety of stimulus situations than either of the 

 extremes. Pavlov went further in his division of the types, 

 however, and attempted to break them up into four groups 

 and relate them to the traditional psychological temperaments 

 of sanguine, melancholic, choleric and phlegmatic. 



The sanguine type includes those dogs which are prone to 

 inaction and inhibition under experimental conditions when 

 single stimuli are employed. Pavlov states, however, that if 

 many stimuli are used, eliciting both positive and negative 

 reactions, they become more active. This is also true of 

 group A, but if the two extreme types are compared in the 

 same situation, there will always be the same relative differ- 

 ences between them. For example, the dogs of group A tend 

 to become inactive under experimental conditions, but if a 

 number of stimuli are introduced, and also more than one 

 channel of reaction, they do become more active. On the 

 other hand, if the dogs of B are studied under the same con- 



