BIOLOGY IN HUMAN AFFAIRS 



Human society is similar in many respects, but funda- 

 mentally different in psychology. In union there is strength, 

 in animals or in human groups; and in both cases there is 

 efficiency in specialization. But individual initiative and 

 adaptability, as opposed to caste specialization, and almost 

 the whole of that cumulative and changing social product 

 called culture, can be found only where behavior is intelli- 

 gent — that is, in human society. Instinctive behavior 

 depends upon inherited patterns in the nervous system and, 

 as practiced by the insects, can produce highly complex 

 social relations which are eminently successful, if the 

 individual is devoid of aspirations toward independence, 

 and if environmental conditions remain substantially 

 constant; while intelligent behavior depends largely upon 

 learning and experience in the individual and, as practiced 

 by man, can produce institutions equally complex but 

 far more adaptable to varied conditions and, furthermore, 

 distinguished by a historically developing culture of 

 esthetic and technological character. Among the other 

 vertebrates some traces of intelligence can, of course, be 

 found, and these give zoological evidence of the way in 

 which intelligent behavior evolved along its divergent 

 and continuing way while instinctive behavior reached its 

 early summit . . . and limit. 



In both cases the advantages of social life have been 

 fully demonstrated, and in the course of time, the social 

 organisms have come to dominate the solitary types. Many 

 of the latter, it is true, have escaped extinction on account 

 of some special quality, such as extreme fecundity, wide 

 latitude in food requirements, or exceptional adaptation 

 to peculiar conditions; but the power of social solidarity 

 has been a notable factor in natural selection, and goes 

 far to explain the success of the ants and of man. The 

 Darwinian principle, one of the great generalizations of 

 biology, has been exemplified in the development of 



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