THE INHERITANCE OF MENTAL ABILITY 113 



problem. So eminent an authority on insanity as Dr. Henry 

 Maudsley has stated, ''It is no exaggeration to say that there 

 is hardly ever a man of genius who has not insanity or nervous 

 disorder of some form in his family." Moreau de Tours who did 

 much to bring the relation between genius and insanity into 

 prominence regarded genius as a "neurosis, or abnormal exalta- 

 tion of the intellectual faculties." Lombroso, who has written 

 most copiously on this topic, finds that men of genius commonly 

 exhibit neuropathic traits indicative of a degenerate taint, and 

 have many peculiarities in common with the actually insane. 

 The foibles, eccentricities and weaknesses of men of genius have 

 afforded a theme for almost endless comment. And it is not to be 

 wondered at that those who contend that genius represents a sort 

 of pathological variation have no difficulty in collecting a number 

 of instances which fit their case. But a doctrine based on evi- 

 dence especially selected to prove the thesis rests upon a very 

 inadequate basis. What most of the writers who have accepted 

 this doctrine have done is simply to collect all the cases that they 

 could find in which men of eminence became insane or exhibited 

 occasional eccentricities. However extensive and imposing such 

 a collection of facts may be, it really proves nothing if one ex- 

 cludes, as is usually done, the very numerous cases which do not 

 bear out the theory. 



The obviously scientific method of attacking the problem 

 would be to ascertain the percentage of insanity in a rather large 

 random sample of people of superior ability, and to compare it 

 with the percentage of insanity in the general population of 

 corresponding limits of age. The only writer with whom I am 

 acquainted who has ever attacked the subject by an impartial 

 statistical method is Havelock Ellis in his Studies of British 

 Genius. Selecting, according to certain rules, 1,030 names from 

 the Dictionary of National Biography, he found that, even when 

 slight or dubious cases were included, the percentage of men and 

 women who became insane was not more than 4.2 per cent. A 

 study of the parents of these British men of genius showed, 

 contrary to Maudsley's statement, that insanity could not be 



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