THE INHERITANCE OF MENTAL ABILITY 99 
“The influence of heredity, which it is now the fashion to rate so 
highly, is as nothing compared with the influences which mold 
the man after he comes into the world.” 
The establishment of the theory of evolution, and its applica- 
tion to the development of mankind could scarcely fail to direct 
renewed attention to the inheritance of mental qualities in man. 
Inspired by this doctrine and stimulated by the writings and 
personal influence of his cousin, Charles Darwin, Francis Galton 
was led to undertake those studies on inheritance by which he has 
since become famous. The investigations which Galton made 
upon the inheritance of ability were embodied in his celebrated 
volume on Hereditary Genius. In this work Galton showed that 
superior ability runs in certain families to a very marked degree. 
We are all familiar with families which are celebrated for the 
number of their great names: In science, the Herschels, Ber- 
nouillis, De Candolles, Darwins and Gregorys; in literature, 
the Brontés, the Arnolds, the Hallams, and the Lowells; in music, 
the Bachs and the Mendelssohns. It might be contended that the 
occurrence of such groups is purely fortuitous. Even if there were 
no transmission of ability or any other reason why persons of the 
same family should become distinguished it would be possible, 
from all the great men in the world, to pick out a considerable 
number of cases in which two or more men of great ability hap- 
pened to belong to the same family. Galton, who was too critical 
an investigator to base his case merely on evidence especially 
selected to prove his theory, undertook an impartial statistical 
inquiry into the families of eminent men in order to ascertain how 
far the data obtained would yield evidence of the hereditary basis 
of great ability. Eminent men were classified into several groups, 
judges, scientists, literary men, statesmen, poets, musicians, 
painters and divines. The basis for selection varied with the 
different groups, but was in all cases made so as to include the 
most eminent persons regardless of heredity. Then the endeavor 
was made to determine to what degree eminent men in these 
groups had eminent relatives. It was shown that eminent men 
have eminent relatives to an enormously greater degree than do 
