HUMAN INFANCY 27 



the fact that any element or group of elements in the whole general 

 response can be discriminated and seized upon by the individual. 

 Training implies that elements from these random movements result- 

 ing from the diffusion of the discharge produced by a stimulus, are 

 valued and selected. The interest is concentrated upon the pleasurable 

 element, and more and more of the diffused discharge is led through the 

 selected channel. The person by repeating a process a sufficient number 

 of times becomes as automatic in the response as though controlled 

 entirely by the lower centers. 



It is obvious that the greater the number of cortical cells in the 

 brain, the greater number of associations possible, and the greater the 

 range, therefore, of psychical activity. Education and adjustment 

 imply to a very large degree sensori-motor connection. The creature 

 having only one sensori-motor path can have only the very most limited 

 associative power, or power to learn by experience. The greater the 

 number of possible connections the greater the teachableness, but at 

 the same time the longer a period of time it takes also to make complete 

 adjustment. 



The lowest vertebrate animal, Amphioxus, has no infancy. The 

 young do whatever the parents do, the only difference being the size. 

 This animal has no cerebrum. It does not care for its young. Neither 

 can it learn by experience. Fishes have very little cerebral brain. 

 They have no perceptible helplessness at birth. In birds the brain 

 develops, infancy extends, and the maternal instinct appears. Most 

 birds are also quite teachable. Dogs, horses, and apes are teachable. 

 The manlike apes of Africa and the Indian Archipelago have advanced 

 beyond the mammalian world. They have greater brain capacity, 

 greater intelligence, also a greater period of helplessness. These tailless 

 apes are helpless for some three months. During this time they are 

 unable to walk, to feed themselves or to grasp things with precision. 

 The human infant has a very much longer period of helplessness than 

 any of the other animals. And when we compare the size of man's 

 brain and his achievements with those of other animals, we have 

 demonstrated to ourselves in an overwhelming manner the above 

 assumed correlations. 



