HUMAN GENETICS 357 



individuals whose hereditary inferiority is by no means obvious, such 

 as the blind, the deaf or the pauper. Clearly there is no genetic justi- 

 fication whatever for sterilizing an individual unless it can be shown 

 that he carries defects which are certainly hereditary. The danger of a 

 sterilization policy being influenced by political, religious, or other pre- 

 judices is very great. Moreover, it must be remembered that steriliza- 

 tion of a defective may not only remove a deleterious gene from the 

 human stock, but may deprive it also of valuable hereditary material 

 carried in the same individual. Mr. H. G. Wells, for instance, is a 

 diabetic, but one would hardly on those grounds place him on the 

 debit side of the human balance-sheet. 



Sterilization seems to be almost the only method of reducing fertility 

 which has been advocated. The project which is perhaps most charac- 

 teristic of the eugenical programmes which have been put forward is 

 the encouragement of fertility in the carriers of favourable genes. If 

 this proposal is made in general terms, we are involved in the very 

 difficult task of deciding which genes are imusually valuable and 

 worthy of encouragement. Often, however, reformers content them- 

 selves with attempting to remedy ills which they claim are proceeding 

 under our eyes; the most noticeable, of course, is the differential 

 fertility between the upper, and apparently more intelligent, classes 

 and the lower, putatively inferior, ones. This inequality, it is urged, 

 should be evened out or perhaps reversed, the method proposed being 

 usually a system of family allowances.^ None of the systems of this kind 

 which have been tried in various countries seem to have been effeaive; 

 but most systems of family allowances have been designed rather to 

 push up the birth-rate in general than to adjust relative fertilities. The 

 levelling up of fertilities which has occurred in some places during 

 recent years cannot be attributed to any conscious eugenical measures. 



In the discussion, in a previous section, of the I.Q. of different 

 classes, it became clear that the environment plays an important part 

 in determining the differences which are found. No sensible eugenical 

 proposals can neglect this important fact. It is clear, for instance, that 

 it would theoretically have been possible to reduce the incidence of 

 small-pox from that characteristic of mediaeval Europe by breeding a 

 resistant stock; but suitable hygienic measures such as vaccination are 

 much easier to apply and much more efficient. Similarly, it is very 

 probable that a much greater improvement in intelligence could be 

 produced by measures of social amelioration than by any eugenical 



^ Cf. Fisher 1932. 



