The (olkxal of Hkrrdity 



body of prepotent individuals within 

 the undesirable class would exert a 

 considerable harmful influence, because 

 their marria<i;es with normal persons 

 would result chiefly in the production 

 of undesirable children. 



UPSETTING THE EQUILIBRIUM. 



In considcrinj^ the influence of mar- 

 riage in affecting the distribution of the 

 three classes in the next generation of 

 the community, we may notice that in 

 general the marriages of nonnals tend 

 to keep things just as they are. That 

 is, they tend to produce a large class of 

 normals and two small classes of desir- 

 ables and undesirables, in just about the 

 same relative proportions as in the pre- 

 ceding generation. 



The marriages of the desirables, on 

 the whole, tend to raise the average of 

 desiraVjility in the community; and the 

 marriages of the undesirables tend to 

 lower it. The desirables pull the average 

 upwards, the undesirables pull it down- 

 wards; and when these upward and 

 downward tendencies are just equal 

 they neutralize one another and a static 

 condition ])revails: The race as a whole 

 neither advances nor recedes. 



If the potency of the desirable class 

 to produce desirable children is greater 

 than the potency of the undesirable 

 class to produce undesirable children, 

 then we have a case of unstable equi- 

 librium, and the whole race begins to 

 move u]nvards. 



Conversely, if the ]3otcncy of the un- 

 desirable element is greater than that 

 of the desirable element, then the race 

 begins to move downwards. 



Thus, it is the difference between the 

 potencies of the desirable and undesir- 

 able classes that controls and determines 

 the amount and direction of the racial 

 movement. 



If, then, we wish to improve the race 

 the aim should ])e to increase the potency 

 of the desirable class to produce desirable 

 children; and this can be aeeomi)lished 

 by promoting the marriages of the de- 

 si rafjlc with one another. 



The moment wc have a body of desir- 

 able persons whose parents were also 

 desirable, imjjrovement of the race be- 

 gins through the marriage of such ])er- 



sons with the normal population : for the 

 proportion of desirable offspring bom 

 from the normal jjartners will be greater 

 than in cases where the desirable part- 

 ner had no ancestors belonging to the 

 desirable class. 



The improvement will be still greater 

 when we have a body of desira]:)le 

 l^ersons who had grandparents as well 

 as parents desirable; and still greater 

 with each increase in the number of 

 desirable ancestors. 



Thus, the simj^le process of promot- 

 ing the marriages of the desirable with 

 the desirable will, through the mixture 

 of the descendants with the rest of the 

 population, inaugurate an improve- 

 ment of the whole race; and the move- 

 ment will advance with accelerated 

 velocity as we have more and more 

 potent individuals of the desirable 

 class. This process continued through 

 a number of successive generations 

 would ultimately result in the estab- 

 lishment of a i^repotent stock within 

 the desirable class, and then the im- 

 provement would be \'ery marked 

 indeed. 



CHIEF OBJECT OF EUGENICS. 



Here it is to be noted that the elevat- 

 ing tendency is due to the desiral^le 

 class alone; and that improvement 

 de]5ends upon increasing the number and 

 proportion of desirables born in successive 

 generations of the population. Hence, this 

 should be the chief object of eugenics; 

 and it is to be regretted that the efforts 

 of eugenists have been mainly directed 

 to the diminution of the undesirable 

 class. 



So much has this been the case that 

 the very word "eugenics" is suggestive 

 to most minds of hereditary diseases 

 and objectionable abnormalities; and 

 of an attemi)t to interfere, by com- 

 ])ulsory means, with the marriages of 

 the defective and undesirable. This 

 relates to cacogenics ("badly born") 

 rather than to eugenics ("well born"). 



The utmost that could be even hoped 

 for from such a process would be to 

 lessen the tendency to retrogression 

 and degeneration; and even this result 

 would not be attained, at least in any 

 great degree, for the sim])le reason that 



