HEREDITY IN MAN 109 



stature, where correlation both between father and son 

 and between brothers has been measured, it is found that 

 they give very nearly the same figure. If, therefore, we 

 find that in the above Table the correlation between 

 brothers is -46, we may take it that for all practical 

 purposes this is also the intensity of inheritance. 



A similar investigation for Harrow School gave a 

 slightly lower value, the average for the two schools being 

 about -4. We can, therefore, say that these investigations 

 indicate a strong inheritance of ability, though about 

 20 per cent, less intense than the inheritance of stature. 

 It must be mentioned, however, that Pearson's school 

 schedules, compiled on a different principle and with 

 different material, gave the intensity of inheritance of 

 intelligence as -5, or equal to that of stature. 



Pearson has made an attempt to measure the inheri- 

 tance of the most varied human characteristics by the 

 same method of measuring the resemblance between 

 members of the same family. His method was to send 

 out schedules to a number of schools (nearly 200), con- 

 taining directions, and tables to be filled up for (i) pairs 

 of brothers, (2) pairs of sisters, (3) pairs consisting of 

 one brother and one sister, for a number of physical and 

 mental characteristics. Limiting ourselves again to the 

 results for brothers (those for the other combinations 

 being closely similar) we can take as examples Tables 

 4 and 5, noting again the excess of ' numbers actually 

 found ' over those ' expected ' in the cases where the 

 brothers are alike, and the deficiency in the cases where 

 they are unlike, thus indicating the action of in- 

 heritance. 



