THE INHERITANCE OF MENTAL ABILITY 107 
ability. It is quite well established that high standing in college 
is correlated with success in later life. Should it be found, there- 
fore, that sons in the honor class have a relatively large proportion 
of fathers in the high honor class, while sons of the “pass” or 
ungraduated classes have a relatively large proportion of fathers 
in these classes also, it would offer strong evidence of hereditary 
differences in ability. The results of the study may be summar- 
ized in the following table: 
Scholarship of Fathers and Sons at Oxford 
Percentage of Fathers 
Sons Obtaining Obtaining First or Second 
Class Honors 
First class honors............-41.9 
Second class honors........... 40.7 
Third class honors.... .......33.3 
Fourth class honors.. ..... 28.1 
Pass degree....... 00 ........ 20.1 
INO GERTECN or hicdecmnsaeead 12.9 
The striking feature of this table is the regularity with which 
the percentage of high scholarship among the fathers decreases 
as the scholarship becomes lower in the sons. The correlation 
coefficients between father and son were .29 or .31 according to 
which of two methods of calculating the coefficients was em- 
ployed. The correlation coefficient of brother and brother was 
somewhat higher, viz., .405, due possibly to the fact that methods 
of instruction, standards of grading and other circumstances 
were more nearly alike for brothers than for fathers. 
The scholastic records of two secondary schools, Harrow and 
Charterhouse, were investigated by much the same methods, but 
owing to the absence of data concerning the parents the study 
was limited to comparisons between brothers. The data which 
were drawn from several thousand students gave a fraternal 
correlation of .398 which is very close to what was found for the 
students at Oxford. This correlation did not increase sensibly 
with increasing age of the students. 
