TABOO AND GENETICS 89 



of body on the average smaller, weaker and less 

 well adapted to some other activities than is 

 the male body, even when reproduction is not 

 undertaken. A great complication is added by 

 the fact that some women, and also some men, 

 are better adapted than others to nonrepro- 

 ductive activities. This is another way of 

 saying that the type of body associated with 

 either type of sex glands varies a good deal, 

 for reasons and in respects already pointed out. 



The most important fact about this repro- 

 ductive specialization is that be3^ond fertilization 

 it is exclusive in the female. Since the males 

 cannot furnish the intraparental environment 

 for the young, the entire burden must fall on 

 half the group. If this aggregation is to even 

 hold its own numerically, its women must have, 

 on an average, two children each, plus about 

 one more for unavoidable waste — death in infancy 

 or childhood, sterility, obvious unfitness for 

 reproduction, etc., i.e., three in all. If one 

 woman has less than her three children, then 

 another must have more than three, or the 

 group number will decrease. Group survival 

 is the fundamental postulate in a problem of 

 this kind. 



The above figure is for civilized society. In 

 primitive groups, the terrific wastage makes a 

 much higher birth-rate necessary, several times 

 as high in many cases. If we suppose such a 



