GENETIC EFFECTS 19 



pacitating but not lethal condition that is usually not manifest until after the family is complete 

 may produce enormous personal and social damage before becoming extinct. It is indeed 

 conceivable that there is a class of mutations that endows its carriers with capacities for para- 

 sitizing society that cause them to increase in numbers until society collapses. 



Even in lower organisms it is necessary to distinguish between intrademic selection that 

 may in some cases lead to the increase of certain mutations at the expense of the welfare of 

 the population, and interdemic selection that may in some cases lead to the establishment of 

 mutations that are individually at a slight disadvantage but that make for the success of the 

 group. 



As a first step in the problem of appraising genetic damage, it is desirable to attempt 

 some classification of human phenotypes with respect to social value. This is primarily a 

 sociological problem but collaboration is needed between a sociologist familiar with the data 

 and its sociological appraisal, and a geneticist who can aid in the choice of the classification 

 most useful in the light of genetic knowledge. The following rough classification does not 

 meet these specifications but may suffice to indicate the nature of the problem and give a 

 provisional basis for discussion of the genetic problems. 



The social impact of a mutation may be treated in terms of the balance between con- 

 tribution to society and social cost. In general, there is a positive correlation between con- 

 tribution and cost. Those who contribute most also tend to cost the most in terms, for 

 example, of education and standard of living. An injurious mutation may, however, entail a 

 heavy diversion of the efforts of others into a channel that is unproductive to society except 

 from the standpoint of maintaining the sacredness of human life. In dealing with contribu- 

 tions, such efforts must be included even though in a sense wasted, as of course must efforts 

 in rearing one's own or other children. The contribution from fecundity itself, however, is 

 ambiguous. It must be considered separately in connection with genetic considerations. 



It should be added that there is a personal aspect of genetic damage that may not be re- 

 flected to any appreciable extent in social impact. There are many conditions that are per- 

 sonally undesirable but that can be tolerated or remedied so easily that there is little or no 

 effect on the balance of social contribution and cost. The appraisal of genetic damage from 

 this personal standpoint is much more intangible than the impact on society. For the moment 

 we will consider only the latter. 



The various combinations of cost and contribution to society that exist in a human popu- 

 lation are shown schematically in the diagram on page 20. 



The diagonal dotted line is that in which the ratio of contribution to cost is average for 

 the population in question. This ratio may be taken as one in a static society but as greater 

 than one in a society in which there is an advance in well-being in each generation. 



1 . In the first category, which includes the bulk of the population, there is an approxi- 

 mate balance between contribution and cost, but both at relatively modest levels. 



2. In this category, there is also an approximate balance between contribution and cost 

 but both at relatively high levels. Professional men of average competence, but with an educa- 

 tion and standard of living well above the average of the population in cost, fall here. 



3. Here are included those who make an extraordinary contribution at modest cost to 

 society. 



4. In this category are those who cost society much in terms of education and standard 

 of living but who contribute much more than the average at their level of cost. 



5. We may put here a class of individuals whose capacities are those of classes 1 to 4 



