2 34 READINGS IN BIOLOGICAL SCIENCE 



consult reality or reckon with statistics. No breeder of domestic animals 

 or cultivated plants would ever expect to improve his stock by such feeble 

 methods. They are necessary to prevent further deterioration but they 

 offer little or no hope of great improvement. 



The difficulty, or rather the impossibility, of any more radical program 

 of eugenics than is involved in the gradual reduction of the fecundity of 

 the worst human types and the encouragement of greater fecundity in 

 the best types makes it extremely improbable that any great or rapid im- 

 provement in the inherited nature of the human race can be produced by 

 eugenics. It is relatively easy for the breeder of animals or plants to choose 

 the types which he wishes to propagate and to make new combinations 

 of desirable traits, but the case is far different in man where in the main 

 restrictions on reproductions must be self-imposed, where there is little 

 uniformity of opinion among different peoples and in different times as 

 to what is the best human type, and where social and moral customs are at 

 variance with the best methods of the breeder. 



Alexander Graham Bell,^ inventor of the telephone, was a skillful 

 breeder of sheep and was also greatly interested in human eugenics. He 

 had found that he could by selective breeding produce a breed of sheep 

 in which twins were produced at almost every birth, and then by further 

 selection, ewes with four functional teats, instead of two, were produced. 

 But he pointed out the differences in the technique of sheep-breeding as 

 compared with the social conditions governing human reproduction, 

 by supposing that the sheep breeders were compelled to observe the cus- 

 toms which prevail in the most advanced human society, namely (i) 

 all must be allowed to breed and none must be sterilized, (2) weaklings 

 and deformed individuals must receive special care and must be permitted 

 to propagate, (3) polygamous and consanguineous unions must not be 

 permitted, (4) every individual must be allowed to choose its own mate 

 and for hfe. Under such conditions, he says, no improvement in a flock 

 would be possible, and as long as these social conditions prevail among men 

 no hereditary improvement in the human stock will be possible. But al- 

 ready the first and second of these social customs are being abolished or 

 changed in the most enlightened societies, either by sterilization, segrega- 

 tion of the sexes in public institutions, or by the less drastic method of the 

 social taboo. It does not seem probable that in a free society the third and 

 fourth of these social customs will be abolished, even for the purpose of 

 breeding a race of supermen. Methods of negative eugenics, that is, the 

 prevention of the breeding of defective stock, offer no hope of race im- 

 provement, but only prevention of further deterioration. 



A much more potent means of race improvement, indeed the only 

 means of improving inherited traits, is by the positive method of breeding 



2 A. G. Bell, How to Improve the Human Race, ]our. Heredity, 5, 1-7, 1914. 



