42 TRAITS OF YOUNG CHIMPANZEES 



and the behavior of the animals was accurately noted and 

 recorded. 



Inasmuch as the desire for food is a strong and dependable 

 motive for effort, food was used as reward in all of the tests 

 which are now to be described. 



To begin with I shall present in some detail, by quotation 

 from my notebook, the behavior of Chim in the first type of 

 test situation. 



In an observation room approximately 22 feet long, 12 feet 

 wide and 7 feet from floor to top of beams, with space between 

 beams and roof, a string was suspended to which a banana 

 could be attached at any desired height from the floor. This 

 string could not be reached from any point in the room by the 

 animals. In fact, the nearest approach by side walls or 

 overhead beams was approximately four feet. 



The first record reads as follows: 



At 4.35 a piece of banana was attached to string approximately 150 

 cm. from floor. Single rope which was attached to middle of outer 

 beam for animals' play had previously been hghtly fastened around beam 

 so that it should be out of the way as I supposed Chim would naturally 

 use it to climb and swing on and might accidentally discover that banana 

 could be approached by means of it. 



He was interested immediately in the banana, watched me intently 

 while it was being put in place, looked about the room, climbed up to 

 the outer beam, seemingly measured the distance with his eye, swung on 

 the looped rope which was fastened to the beam at both ends and at one 

 point hung about a foot below beam, descended to floor, looked up at 

 banana, went to outer corner of room and climbed up on Miss 

 Mumpoting's lap as though seeking help, gazed at her a few seconds, 

 climbed down, took another look at the banana, climbed up on outer 

 beam, then down to loop of rope and sat or lay astride the loop swinging 

 there reflectively for perhaps a minute, climbed down again to the floor. 

 It was now 4.45. The end of rope had been lightly wrapped around 

 beam. I noticed it to be loose and when a minute or two later Chim 



