RACE SUICIDE OR A NATURAL LAW? 27 



among the well-to-do. And these childless marriages 

 among the wealthy provide the best test, because here 

 the use of contraceptives as an explanation may be ruled 

 out almost with certainty ; whereas where there are 

 children, even though only a few, it is possible to argue 

 that there are as many as are desired ; while in the case 

 of childless people of limited means it is possible to argue 

 that they do not feel that they can afford to support 

 children. 



We can now examine a few interesting test cases. 

 Darwin mentions that 19 per cent, of the English nobility 

 are childless, " which is more than three times the average 

 for the rest of the nation." l As the English nobility 

 have titles and usually considerable wealth to transmit 

 to their heirs, and as they generally marry for the express 

 purpose of obtaining heirs, this fact requires some other 

 explanation than the use of contraceptives. The late 

 Sir Francis Galton suggested that childlessness among 

 the peerage was frequently due to marriages between 

 the peers and heiresses, who are often the only children 

 of their parents and therefore of infertile stock. This 

 may sometimes be a contributory cause, but as an ex- 

 planation it is utterly inadequate. Only a fraction of 

 the peers marry heiresses, and of these only a small 

 proportion will be of infertile stock. Moreover, the 

 argument is negatived by Galton's own principle of 

 Regression to Mediocrity. If parents are so infertile as 

 to have only a single child during a normal length of 

 married life, they will, in respect of fertility, be abnormal 

 variations variations, that is, a long way from the 

 mean or average of the race. According to the law of 

 Regression to Mediocrity an abnormal variation usually 



1 Dictionary of Statistics, Mulhall. I believe that the percentage is 

 now considerably larger. 



