Habit and Instinct. 



from under the feet of those who regard mental evolution 

 in man as due to inherited increments of individually 

 acquired faculty. Nay, more ; if the average level be not 

 rising, some explanation must be demanded from trans- 

 missionists of this fact. For surely if there be trans- 

 mission of individually acquired increment, the average 

 level of faculty ought to be steadily rising. 



The conclusions reached, then, in this chapter are 

 somewhat as follows. There is little or no evidence of 

 individually acquired habits in man becoming instinctive 

 through heredity. Natural selection becomes more and 

 more subordinate in the social evolution of civilized man- 

 kind ; and it would seem probable that with this waning of 

 the influence of natural selection there has been a diminu- 

 tion also of human faculty. Hence there is little or no 

 evidence of the hereditary transmission of increments of 

 faculty due to continued and persistent use. A discus- 

 sion of heredity in man thus confirms the inference drawn 

 from the study of habit and instinct in some of the lower 

 animals. 



