Recent Work in Heredity 91 



and daughter, and between father and daugh- 

 ter, and the same principle is found true for 

 many other characters. 



If other pairs of .relatives be considered, a 

 similar ' correlation ' is observed. Thus, from 

 knowing the length of the forearm of the 

 brother the probable forearm of the sister 

 can be predicted, while, on comparing the 

 cephalic indices of a large number of pairs 

 of brothers and plotting them against each 

 other, the means of the fraternities of brothers 

 with given head-shape were shown to lie 

 almost upon a straight line. It is found, 

 moreover, that brothers and sisters are rather 

 more like each other than like their parents. 



Similar principles may be applied to the 

 classification of individuals according to 

 mental qualities. Teachers were found to 

 agree to within 85 per cent, in their classific- 

 ation of children according to intelligence. 

 If their classification of a large number of 

 children into ' very dull,' * slow dull,' 'slow,' 

 4 intelligent,' and 'quick intelligent 1 be 

 adopted, it is found that the average child is 

 on the border-line between 'slow' and 'intelli- 

 gent.' If, now, pairs of sisters be classified, it 

 is generally found that the ' slow dull's ' sister 

 will fall somewhere between ' slow dull ' and 

 'slow intelligent,' while the sister of the 

 ' quick intelligent ' will probably be merely 

 ' intelligent.' Thus, again, the exceptional 

 individual indicates an average relative above 



