358 BRAINS OF RATS AND MEN 



enlarged have seen phenomenally rapid development 

 of man's capacity for control of nature and of his own 

 destiny. 



The key to biological efficiency everywhere is con- 

 trol^ a control which is internally determined. Every 

 animal does control his behavior to some extent by 

 virtue of his internal organization. This organization, 

 this inner nature, has grown gradually through the 

 exercise of his own innate powers in adjustment to 

 situations as they arise. It is a creation of his racial 

 and individual biological history. General physiology 

 reveals the procedures employed in this biological 

 control, some of the most important of which have 

 been described by Child (1924). 



Intelligence, reason, abstraction, idealization, in 

 mankind are also part of the biological equipment of 

 the control of behavior, but on a new and higher 

 plane. We are more efficient in controlling the phys- 

 ical world in which we must live than are the beavers, 

 and we can make more adequate preparation for the 

 winter's frost and for other future contingencies than 

 they can. Year by year we are becoming more effi- 

 cient in the transmission of accumulated experience 

 by oral and written tradition. In our social relations 

 we are slowly learning that honesty is the best policy 

 and that morality pays bigger dividends than anti- 

 social practices. And, above all, we are gradually per- 

 fecting the technique of self-control as a means of 

 character-building. 



