Human Infancy and the Recapitulation Theory 89 



ually modified instinctive behavior; that of intelligence, or the 

 more abrupt adjustment of instinctive modes to the perception 

 of related "objects," with its associated revival and desire; that 

 of the imitative and lower types of conceptual intelligence of the 

 primates; and finally the rational learning of man. 41 These 

 are of course not distinct^ marked periods but rather points 

 of emphasis in a gradually changing evolution. To what extent 

 is the series paralleled by the development of the human individ- 

 ual? It is wholly beyond the scope of the present discussion 

 to make a careful study of the correspondence. One can here 

 speak of probabilities only, in view especially of our ignorance of 

 the course of individual development. The underlying organic 

 structures are of course wholly incomparable. They are as 

 unlike as the complicated human nervous system at birth and 

 undifferentiated protoplasm, to refer to the two extremes; or 

 as the infant human and pithecoid brain, to narrow the interval 

 of contrast. The point at issue is whether the rise of psycho- 

 physical functions in the human child follows in an homologous 

 fashion the course marked out by the evolution of behavior. 

 The nervous control of human behavior offers no ground of 

 comparison with the tropisms. With regard to the reflexes of 

 infancy, it is obviously impossible to establish genuine homologies 

 with the lowest animal reflex action systems. In their origin 

 they were undoubtedly removed from primordial phylogenetic 

 systems by inconceivable intervals of time, and their only common 

 attribute is their reflex quality. Moreover, they do not consti- 

 tute an "epoch" in development, in the sense that they are 

 succeeded by a later and different mode or organization, for 

 they persist throughout life. The random movements do sub- 

 side and give way to higher systems, but even if these be regarded 

 as peculiarly ancestral, they are so only as fragments of older 

 more complete instinctive systems and not as representative 

 ancient reflexes. Again, it is not at all obvious that the particu- 

 lar reflexes that remain in man are especially old in comparison 

 with his instinctive make-up. The sucking reflex has risen 

 with the mammals; it is probably much younger than the basic 

 fear structure. What is true of this reflex may be true of others. 



41 See Hobhouse, Mind in Evolution, 1901 ; Morgan, Animal Behavior, 2nd. ed. 

 1908; Holmes, The Evolution of Animal Intelligence, 1911. 



