66 MAN AN ADAPTIVE MECHANISM 



through the ages, will be neutral and unmoved ; while 

 the boy, according to his phylogenetic and ontogenetic 

 experience, either will idly watch the hawk or will try 

 to shoot it. 



Within the species, the experience of the family and 

 of the clan takes the place of the experience of the 

 race in evolving through selection more obvious minor 

 structural and functional differences of manner and 

 habit, color, facial expression, bearing, etc., which 

 distinguish one group from another. The experi- 

 ence of the individual, in turn, will accentuate, neu- 

 tralize or eliminate given family tendencies and estab- 

 lish new thresholds and action patterns, according to 

 the old, the absent or the new stimuli encountered in 

 his environment. 



The extent to which the principle of action patterns 

 and of the automatic specific interaction of stimulus 

 and response helps in the interpretation of physiological 

 processes will appear as our material develops and some 

 of the more obvious specific responses are demonstrated. 



