FACTS AND FACTORS OF DEVELOPMENT 



83 



The phenomena of mental development in 

 man and other animals may be summarized as 

 follows : 



DEVELOPMENT OF PSYCHICAL PROCESSES IN ONTO- 

 GENY AND PHYLOGENY 



All Living Things, In- 

 cluding Germ Cells and 

 Embryos, Show: 



1. Differential Sensitivity = 

 Different Responses to 



Stimuli differing in Kind 

 or Quantity. 



2. Tropisms, Reflex Mo- 



tions = 

 Relatively Simple, Me- 

 chanical Responses. 



3. Organic Memory— 

 Results of Previous Ex- 

 perience registered in 



General Protoplasm 



4. Adaptive Responses = 

 Results of Elimination of 



Useless Responses 

 through Trial and Error. 



5. Varied Responses 

 Dependent upon Conflict- 

 ing Stimuli and Physi- 

 ological States. 



6. Identity = 

 Continuity of Individual 



Organization. 



Mature Forms of Higher 

 Animals Show: 



1. Special Senses and Sen- 



sations = 

 Sensations are the Ele- 

 ments of Mind. 



2. Instincts (Inherited), 



Habits (Acquired) — 

 Complex Reflexes, involv- 

 ing Nerve Centers. 



3. Associative Memory — 

 Results of Experience 



registered in Nerve Cen- 

 ters and Association 

 Tracts. 



4. Intelligence, Reason = 

 Results of Trial and Er- 

 ror plus Associative 

 Memory, i. e. Experi- 

 ence. 



5. Inhibition, Choice, Will 

 Dependent upon Associa- 

 tive Memory, Intelli- 

 gence, Reason. 



6. Consciousness = 

 Continuity of Memory, 



Intelligence, Reason, Will. 



