340 "Journal of Comparative Neurology and Psychology. 



laying hold of the plug and the direction of the pull were con- 

 cerned, both requiring very radical changes from the monkey's own 

 previous efforts."' He also says, "It seems to me that the two cases 

 with the box are quite as good examples of imitation as could well 

 be gotten even with human beings."^ 



Watson's contribution to this subject is the latest and agrees with 

 Thorndike's in giving negative results. He reports three imitation 

 tests made upon two Macacus rhesus monkeys. In no one of those 

 tests did the watching animal learn to get food by seeing another 

 animal get it. He concludes, "I unhesitatingly affirm that there 

 was never the slightest evidence of inferential imitation manifested 

 in the actions of any of these animals."^ 



If we group the work of the three investigators together, we have 

 ten imitation tests in which four animals were used. One animal 

 manifested imitative behavior in two different tests. None of the 

 other three animals showed any tendency to imitate. From such 

 fragmentary and conflicting evidence it is impossible to conclude 

 what role imitation plays in the behavior of monkeys and the need 

 for further investigation is apparent. 



4. Achnowledgments. — In presenting this report of my investiga- 

 tion, I gratefully acknowledge my indebtedness to the Harvard 

 Psychological Laboratory and, in particular, to Professor Robert 

 M. Yerkes, at whose suggestion I undertook the investigation. His 

 sympathetic cooperation at every stage of it has been invaluable. To 

 Dr. William T. Hornaday, Director of the New York Zoological 

 Park, I am deeply indebted for the opportunity to use the facilities 

 of that great institution. His interest and generosity did much to 

 further my work. The photographs which are here reproduced 

 were made for me by Mr. E. R. Sanborn, the Staff Photographer 

 of the Park. I am grateful for his services. 



II. Description and Care of Animals Studied. 

 1. Cehus Monkeys. 

 (a) General Characteristics. — In my experiments I have used 



'P. 144. 

 •P. 122. 

 •P. 172. 



