THE HUMAN SIDE OF APES 



pleading countenance, stretch out his arm to the punisher, 

 if the ape was still being punished, try to hold one arm 

 tight, and finally, with exasperated gestures, start hitting 

 out at the big man!" It is in fact dangerous to punish an 

 ape among a number of adult animals. Even a slight, com- 

 plaining sound may bring the whole pack in an angry assault 

 upon the offending man. It matters little what the cause of 

 the outcry. Even a good-tempered and affectionate chimpan- 

 zee may become suddenly infected with the epidemic of rage 

 that seizes the group, and attack one with whom it had been 

 playing a few moments before. Mob psychology among 

 chimpanzees is only a little more impulsive and unreasoning 

 than it is among ignorant human beings. 



The desire of a chimpanzee to be a member of a group is 

 inordinately strong. If isolated, he is very unhappy. Some 

 fall a prey to fears; others cry, scream, and rage violently 

 until overcome by exhaustion. If a chimpanzee is confined 

 alone in a cage surrounded by his comrades, it often happens, 

 says K5hler, "that if it is only possible for them to get near 

 the prisoner's cage, one or other of the animals will rush 

 to it and put his arms round him through the bars. But he 

 has to howl and cry for this affection to be shown him; as 

 soon as he is quiet, the rest of them do not worry." 



The highly social and sympathetic nature of chimpanzees 

 often leads them to form strong attachments to their keeper. 

 They are quick to sense the emotional attitudes of their 

 human companions and to guide their conduct accordingly. 

 They have their favorites among human beings, often for 

 reasons which appear quite capricious, and they are equally 

 capricious in exhibiting strong dislikes to individual animals 

 as well as persons. They wish to feel that they enjoy the 

 favor of their keeper, and they become very jealous of his 

 attentions to other animals. The pain felt by chimpanzees 



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