THE UNIQUE MAMMAL 11 



ability to talk things over and by so doing to bring the then very 

 rugged individualists into a frame of mind for group effort must 

 have greatly aided in the beginning steps of the emergence of 

 human social behavior. In the early stages of man's racial acquisi- 

 tion of the faculty of articulate speech social approval was prob- 

 ably an important element in speeding up improvement in the 

 new art. Pillsbury and Meader, in their very useful Psychology 

 of Language^ regard as an important element in the transfer 

 of a baby's "gurgles and poppings of the lips" to words, "the 

 incentive that comes from social approval as the early words are 

 spoken, the smiles they draw from the admiring members of 

 the family, and the pleasing way in which they are taken up 

 and repeated." 



It is impossible here, as well as unnecessary for present pur- 

 poses, to go into further detail regarding the part played by 

 articulate speech in human evolution. It will suffice to let the 

 case be summarized in the words of Edward Sapir, a master in 

 the field: "The truth of the matter is that language is an 

 essentially perfect means of expression and communication be- 

 tween every known people. Of all aspects of culture it is a 

 fair guess that language was the first to receive a highly de- 

 veloped form and that its essential perfection is a prerequisite 

 to the development of culture as a whole." And, as the same 

 author says in another place, society, in the more intimate sense, 

 is "a highly intricate network of partial or complete under- 

 standings between the members of organizational units of every 

 degree of size and complexity, ranging from a pair of lovers 

 or a family to a league of nations or that ever increasing portion 

 of humanity which can be reached by the press through all its 

 transnational ramifications." 



There have now been discussed in some detail three of the 

 most important respects in which man may justly be called the 

 "unique mammal," namely his habitually upright posture, his 

 out-size brain, and his faculty of articulate speech. Before leav- 

 ing this phase of the development of our subject, it should be 

 emphasized that in all three of these respects the difference 



