The Mind of a Monkey 261 



in Lizzie's performances in pulling in the board by 

 the two nails. The quickness with which she learned 

 the elements of the trick indicated that she perceived 

 the way in which it might be done by simply in- 

 specting the situation. But we should be cautious 

 in our interpretations, because it was not known how 

 near such actions might have been to her previous 

 experience. Had she, for instance, been used to 

 pulling in branches with fruit attached to them, pull- 

 ing in the board might have been a particular ap- 

 plication of some of her previous activities for which 

 she may have had a strong instinctive bent. 



While it may not be safe to deny to Lizzie a 

 certain amount of prevision in her performances 

 with the board, we should hardly be justified in say- 

 ing that they necessarily involved the drawing of 

 an explicit inference. Should one ask if Lizzie were 

 able to reason, the answer would have to depend on 

 how reason were defined. That some of her acts 

 are the outcome of simple inference, though per- 

 haps not explicitly formulated in her mind, is quite 

 probable. Even perception, as Spencer, Binet, and 

 others have shown, is allied to inference; and Liz- 

 zie's behavior evinces a much closer approach to 

 the rational type than does the process of simple 

 perception. Her behavior does not indicate so high 

 a degree of mental development as that of several 

 other monkeys that have been the subject of ex- 

 periment. Whether her relative ineptitude for cer- 

 tain tasks is an individual peculiarity or a trait char- 



