MENTAL EVOLUTION IN THE PRIMATES 1 35 



apes in their struggle for survival and their eventual dis- 

 appearance from the earth, and the steady advance of 

 man toward perfection of Hfe and of its earthly setting. 



EMOTIONS AND THEIR EXPRESSIONS 



By those who should know, it is said that the chimpanzee 

 more strikingly resembles man in its affective hfe than in 

 any other psychobiological respect. So hke the human are 

 its common expressions of feehng, emotion, mood, and 

 sentiment, that the observer is possessed by a sense of 

 sympathetic understanding. We have advisedly used the 

 terms feehng, emotion, mood, and sentiment because the 

 chimpanzee exhibits in varying degrees these several forms 

 of affective experience. Probably there is no primary human 

 emotion whose counterpart may not be discovered in this 

 organism, or, for that matter, in any one of the man-hke 

 apes. Only apes and men commonly manifest in unmis- 

 takable ways joy, elation, anticipation of pleasure or 

 discomfort, depression, melancholy, dread, fear, terror, sus- 

 picion, resentment, anger, dislike, sympathy, friendhness, 

 sohcitude, jealousy — the hst might be extended almost to 

 the hmit of human experience. To those who are intimate 

 with the ways of the anthropoid apes, their actions, whether 

 emotional or cognitive, are as meaningful as words. 



Even to the relatively inexperienced observer it usually 

 appears that the affective hfe of the apes is more nearly 

 human than is the intellectual or cognitive. Likewise for 

 the scientist it is a commonplace that the affective expres- 

 sions of ape and man are remarkably similar; their expres- 

 sions of cognitive and vohtional experiences markedly 

 different. Indeed, the two widely sundered and at the same 

 time similar classes of creature hve in sharply contrasted 

 perceptual worlds and react to aspects of those worlds with 

 extremely different interests and possibihties of insight and 

 foresight. They may "feel" ahke, while "acting" differently! 



In support of our general statements we present a single, 

 but we beheve typical, instance of the approach of primate 

 to human affective experience and expression. We have 

 selected the appearance of sympathetic relation between 

 mother and infant. 



