GENETIC EFFECTS 21 



but whose return to society is definitely less than their cost for such reasons as unearned 

 wealth. 



6. We may put here individuals of normal physical and mental capacity whose cost to 

 society definitely outweighs their contribution because of the antisocial character of their ef- 

 forts: charlatans, political demagogs, criminals, etc. 



In the remaining categories cost to society definitely outweighs contribution because of 

 physical or mental defects. 



7. Subnormal physical constitution and health. 



8. Low mentality but not complete helplessness. 



9. Normal to maturity but relatively early physical breakdown, either from accident, 

 infectious disease, or relatively early onset of degenerative disease. The seriousness of the 

 deviation from a normal balance of contribution and cost varies with the earliness of onset and 

 the duration of the period of disability. 



10. Mental breakdown after maturity, especially from one of the major psychoses. 



1 1 . Complete physical or mental incapacity throughout a lifetime of more or less normal 

 length. 



12. Death before maturity and too early for any appreciable contribution to society. 



13. Death at or before birth. 



Categories 1 to 4, in which contribution balances or outbalances cost, include an enor- 

 mous diversity of type. It is not necessary for our purpose to attempt to characterize them 

 further. 



Category 5 is almost wholly nongenetic and needs no consideration here. 



Category 6 which is probably the most damaging to society is unfortunately highly con- 

 troversial with respect to the roles of heredity and environment and must be considered 

 further. 



The remaining categories (in all of which cost to society outweighs contribution) all un- 

 doubtedly include a significant genetic component. They overlap broadly in location on the 

 cost-contribution diagram. Each could be subdivided according to levels of cost and contribu- 

 tion but this is unnecessary for our purpose. 



Fecundity is not included in the concept of contribution because of its ambiguous sign. 

 In general high fecundity may be considered as making a positive contribution in categories 

 above the line of balance and a negative one below, not only for possible genetic reasons but 

 also for directly social ones. The line between positive and negative contribution may be con- 

 sidered to shift up or down somewhat according to whether there is over or under population. 

 Fecundity seems to be actually highest in category 1 and to fall off in all directions. It is 

 practically zero along the bottom line. 



The diagram does not bring out the value of diversity. Particular types in the broad cate- 

 gories (1 to 4) along or above the neutral line tend to have value inversely to their frequen- 

 cies. There may be too many or too few in a subclass with particular qualifications for a well- 

 balanced society. 



We come now to the enormously more difficult problem of genetic appraisal. The best 

 first step seems to be a classification of the processes by which each sort of mutation is main- 

 tained in the population. 

 A. Mechanism of equilibrium primarily that of opposed selection pressures. 



1. Positive selection coefficient below a certain frequency, negative above. 



2. Heterozygote favored over both homozygotes. 



