IO4 



THE TREND OF THE RACE 



considered, on the whole, to have a fair amount of accuracy. 

 Various physical measurements of the children were also taken, 

 so that it was possible to compare the resemblance of the children 

 in mental characteristics with their resemblance in physical 

 characters. The correlations between brother and brother, sister 

 and sister, and sister and brother for various physical characteris- 

 tics averaged about .5. The fraternal correlations in mental and 

 moral characteristics are expressed in the following table: 



Resemblance of Siblings in Mental Traits 



It is certainly remarkable that siblings should not only resemble 

 one another in several mental and moral traits to so nearly the 

 same degree, but that the degree of resemblance should be just 

 about the same for both mental and physical traits. If the fra- 

 ternal correlation for mental ability or temper is about the same 

 as the fraternal correlation for eye color and cephalic index 

 (characters not sensibly influenced by the environment) we must 

 conclude, as Pearson argues, that correlations in these mental 

 characteristics are due mainly to inheritance. Of course associa- 

 tion, similarity of home environment, and common training may 

 tend to increase these correlations. If a favorable home environ- 



