CHAPTER XV. 



HEREDITY IN MAN. 



An investigation which deals with habit and instinct is in 

 large degree a study in heredity. It will be of interest to 

 inquire whether the conclusions we have reached are of 

 any assistance in interpreting the phenomena of human 

 life ; and whether what we may learn of heredity in man 

 reflects any light on the problems of heredity in the animal 

 world. 



To this end it will be well to pass rapidly in review the 

 more salient of our conclusions. Stated with the utmost 

 brevity, they are as follows : — 



1. The activities termed instinctive are characterized 

 by relative definiteness of motor co-ordination, probably 

 dependent on congenital structure in the lower brain and 

 spinal centres. Under appropriate conditions a stimulus 

 gives rise to adaptive behaviour without previous learning 

 or experience. 



2. The instinctive response is, as such, unconscious ; 

 but the performance of the instinctive activity affords, 

 through afferent channels, data to consciousness. 



3. These data are linked by association with those 

 supplied by the special senses. 



4. In addition to the co-ordinated outgoing currents 

 to the motor organs concerned in the instinctive response, 

 there are co-ordinated outgoing currents to the viscera 



