BIOLOGICAL EVOLUTION 79 



existence of all human qualities is to be explained, if at all, on 

 the assumption that they have been of value on the whole in the 

 struggle for existence. 



Some modern genetic psychologists and sociologists, working 

 on the above premises, and studying the behavior of animals and 

 infants to get a clue to the behavior of man, have formulated the 

 following conclusions which may well be included with the 

 above : — 



When unconscious reactions were not adequate to survival, 

 consciousness, in some cases, seems to have arisen as an adaptive 

 response to this need, and having arisen, developed rapidly. 1 



Every organism tends to respond positively to stimuli that 

 are favorable and negatively to those that are unfavorable, and a 

 favorable reaction tends to be repeated. In this way innate 

 tendencies are modified and habits formed. 2 



In higher organisms endowed with feeling, reactions that are 

 favorable to the individual or species are accompanied, on the 

 whole, by pleasurable sensations, those that are unfavorable, by 

 painful sensations. 3 



With the development of the human intellect giving man the 

 power of selection among satisfiers of felt needs arose the possi- 

 bility of a selection that was detrimental to the organism and to 

 the species. 4 



With the rise of conscious, purposeful choice, came the power of 

 active adaptation, — i. e., the purposeful modification of the 

 individual or group to make it better adapted to life conditions, or 

 the purposeful modification of the life conditions to make them 

 more favorable to the individual or group. 5 



1 Ellwood, Sociology in its Psychological Aspects, p. 98. 



2 Ibid., pp. 106 f.; Thorndike, Original Nature of Man, ch. IX. 



3 Parmelee, op. cit., pp. 232 £.; Ward, Pure Sociology, p. 130: " All pleasure is 

 mandatory and all pain is monitory. ... So long as feeling and function are 

 adapted pleasure means life and health and growth and multiplication, while pain 

 points to danger, injury, waste, destruction, death, and race extinction." 



4 Miller, op. cit., pp. 44 f. 



6 Ellwood, op. cit., pp. 104 f. 



