2 JOSEPH PETERSON 



on the problem is likely due to the mind-body relations implied 



in the early form of its statement. 



It is desirable to rescue any problem as to how learning goes 



on from mere theoretical discussions. Professor Watson has 



already attempted this for the problem in question, though 



not yet with marked success. 5 Two groups of rats were allowed 



to solve individually a certain problem; in the one group each 



animal was fed immediately after the successful movements 



that brought it into the food box, while in the other group each 



rat was not allowed to take food for thirty seconds after entrance 



to the food box. No difference in the learning of the two groups 



was found. The experiment is regarded as only preliminary 



to a further study of the matter. Two criticisms may be offered 



on this experiment. In the first place, it is not on a wholly 



objective basis. As reported the experiment did not seem to 



be free from the assumption that the question at issue is whether 



the pleasure of the eating had a " stamping-in " effect, to use a 



term of Thorndike's, on the processes leading up to the eating. 



" Successful movements " seem to be regarded as movements 



bringing about this pleasure. If, in the second place, this is 



not the true meaning of the author, it may be suggested that 



the test of the effect of " successful movements " is not adequate, 



since precisely the same kind of acts was necessary for both 



groups of animals to get out of the situation presented by the 



problem. Experience with rats will certainly suggest that after 



an animal has once been fed in the food box it will for a time 



work energetically and learn to run the maze without further 



feeding of the kind, particularly if the odor is not carefully 



excluded. As the habit becomes partly fixed it is questionable 



whether the feeding, or even the smell of food, has very much 



to do with the energy that the animal displays. So far as the 



writer's own experience goes — though he has made no definite 



test of the matter — it appears that once the habit is well under 



way the animal will display great energy in the usual way as 



soon as placed into the entrance box; that the habit will unwind 



itself on the basis of the numerous other stimuli which have 



accompanied the process before. However, any criticism of 



Watson's exp eriment on the basis of his report of the preliminary 



6 An abstract of the experiment, which was reported in the Chicago convention 

 of the American Psychological Association, is printed in Psychol. Bull 1916 13. 

 p. 77. " 



