MENTAL AND MORAL HEREDITY IN ROYALTY. 371 



with known pedigrees, and see how closely the characters of persons 

 correspond with what we should expect were heredity the sole cause 

 of mental and moral peculiarities — in other words, see if the results 

 are as certain when applied to mental traits as to the more physical 

 and tangible qualities like eye and hair, color, stature, etc. If it 

 should be found that the human mind and moral character are subject 

 tc the law of Galton, and with an accuracy as constant as the coloration 

 of animals, then we may conclude that the mind and character are very 

 strongly inherited, since coloration in animals is due to what we at 

 present at any rate consider heredity. Of course we do not expect 

 to find the same accuracy in dealing with psychic aspects, since every 

 one knows that moral traits, for instance, are much the result of 

 environment — education, example, etc. Let us, by studying human 

 characters and comparing them with their close blood relations, see 

 how strong inheritance appears to be. 



It is often impossible to say in any individual, how much is due 

 to one and how much to another cause, but by taking a large number 

 we may estimate in a rough way the proportionate reliance that is to 

 be placed on each factor on the average. Galton's law, based on 

 stature and color in animals, in human hair and eyes, etc., is this : 

 Each child inherits one half of his make-up from his parents, one half 

 of the remaining half from his grandparents, one half of the remain- 

 ing one fourth from his great grandparents, and so on to infinity. 

 Thus each parent contributes one fourth of the entire influence, each 

 grandparent one fourth of one fourth, each great grandparent one 

 eighth of one eighth, or one sixty-fourth, and so on. So we see how 

 little is the influence to be expected from heredity from one dis- 

 tinguished great grandfather. 



In order to get material for such a study, one might take indi- 

 viduals at random and then their brothers and sisters and all their 

 ancestors to a reasonable degree of remoteness, say all the great grand- 

 parents, which would give 87% per cent, of the entire influence. This 

 would be extremely difficult, as it is almost impossible to verify even the 

 names of all the great grandparents of most people, let alone their 

 mental and moral traits. Or one might use a large number of uncles 

 and aunts to determine the latent inheritance of the ancestry, not 

 known in the parents. Unless one had some proper way of selecting 

 the material he might take instances that illustrate some theory and 

 neglect others that do not. 



The method I have employed has been to take individuals merely 

 by blood relationship, and include every person about whom anything 

 could be found. By doing this, I have escaped any selection of cases 

 which illustrate a theory and at the same time know the exact blood 

 relationship of every person to every other person. Of all families 



