DIMINISHING ENVIRONMENTAL INFLUENCE 331 



approximately their relative influence, are all in substantial agreement. 

 The first light thrown on this question comes from Gal ton's " History 

 of Twins/' 43 published as loug ago as 1883. The traits under discus- 

 sion were physical resemblances, diseases, mannerisms of action, mental 

 disposition, temperament and tastes. The data are not given in com- 

 pleteness, nor in statistical form, but the conclusion seemed to him war- 

 ranted that, as regards such mental and physical differences as were 

 under discussion, nature prevails strongly over nurture, within the 

 limits which Galton is careful to assign to the latter. This belief was 

 arrived at from a comparison of thirty-five pairs of very similar twins 

 with twenty pairs of dissimilar twins. 



Those twins who were similar when young remained so in general, 

 as they grew older ; but more significant than this, there appeared to be 

 no tendency for similarities in education and home life to render those 

 originally unlike any more similar with advancing years. The con- 

 clusion from Galton's " History of Twins " seemed to be that if the en- 

 vironmental differences are slight no appreciable effect is produced at 

 least upon innate mental differences which are themselves comparatively 

 slight or unimportant, such as differences in tastes, temperament and 

 disposition. This would of course not prove that the more important 

 human differences, such as are represented by success or failure, vices 

 and virtues, are not profoundly modified by environment if the differ- 

 ences in surroundings are considerable. 



The history of royalty offers just these remarkably wide differences 

 of an environmental nature. This is somewhat surprising because one 

 might assume that the surroundings would be uniformly superior, 

 as aH are of the highest social rank. But for various reasons the in- 

 dividuals have developed under the greatest variety of good and bad 

 influences as regards the atmosphere of their home life, their educa- 

 tional advantages, and opportunities for distinction. Besides, they have 

 lived in different countries and in different eras. Yet, in spite of the 

 fact that the environments show wide variations, these appear to be 

 negligible factors in the production of successful achievement or in the 

 creation of virtuous or vicious types. 



That successful achievement is almost entirely due to differences 

 in germ-plasm and is little influenced by environment is the necessary 

 conclusion from the complete analysis of two separate groups of 

 royalty. One of these is the great interrelated group of 3,312 distinct 

 persons in Lehr's Genealogy. This book contains many repeated 

 names, because the same individual appears as an ancestor of different 

 lines, owing to intermarriages. Thus the total number of cases for 

 statistical purposes is much greater than 3,312. It is in fact 32,768, 

 for this book contains eight " families " with 4,096 in each family. 

 Out of the 3,312 different persons there were sixteen who came up to 



43 "Inquiries into Human Faculty," 1883, pp. 216-243. 



