282 HUMAN BIOLOGY 



SPONTANEOUS ATTRACTIONS AND AVERSIONS 



Among the more intangible factors in human sex hfe are 

 the spontaneous attractions and aversions between the 

 sexes. Romantic love is supposed to be pecuhar to cultured 

 nations, but something hke it turns up among the most 

 primitive. Elopements are frequent among the Austrahan 

 natives and in Africa the warrior is said to go into battle 

 singing of his lady love. Aversions on the one hand and 

 spontaneous attachments on the other seem everywhere 

 to result in the breaking of law and custom and these unions 

 are, for a time, monogamous. Here may be a reassertion of 

 the basic behavior that forms the biological background to 

 marriage. With these factors go jealousy and the effort to 

 maintain the exclusive relationship set up, which also seem 

 to be natural responses. In this way it seems possible to 

 arrive at a behavioristic view of marriage, or at least to 

 justify it as a social necessity in the harmonious functions 

 of community life. 



So far we have not referred to the aversion known as 

 "incest." Though a great deal of thought has been given 

 the subject there is still no unanimity of opinion as to whether 

 incest is instinctive or conventional. All peoples make a 

 distinction between an incestuous group and those among 

 whom sex relations may be established, but these distinc- 

 tions, while eminently practicable, are variable and arbitrary. 

 If incest is an instinct, it is difficult to see what biological 

 use it serves. The old idea that inbreeding was destructive 

 has met with little support from experimental biology, 

 though some doubt is expressed as to how incest would work 

 in a small savage tribe which is, for the most part, inbreeding. 

 In such cases incest would serve as the only check to free 

 mating. But the inbreeding argument is so weak that most 

 supporters of the instinct theory of incest fall back upon 

 aversion toward those with whom one is closely associated, 

 as parents and children, brothers and sisters. Psychologists, 

 on the other hand, are disposed to regard the incest aversion 

 as a result of repression. A survey of primitive practice 

 reveals a universal taboo on unions of mother and son; 

 the case for father and daughter is not so strong, because 



