GROUP ORGANIZATION 205 



is A, C, Y, M, E. This same order holds for total to 

 contacts and for both total and to contacts in the 

 thirty-two to thirty-six months' period. The diagrams 

 on the right show that A initiated the most to con- 

 tacts, and that C was next. Beyond that the order 

 varies. For the whole period of observation (upper 

 row) it is M, E, Y, and for the last period (lower 

 row) it stands as M, Y, E. 



The other available data do not always give this 

 same order, but enough has been presented to show 

 that, among these children identical in heredity and 

 almost so in post-natal environment, there are social 

 differences which can be recognized by the behavior 

 of the children toward each other. 



As the figures giving mental rank indicate, the 

 correlation with intelligence is by no means perfect. 

 Neither is the correlation with size. Y, the largest, 

 and said in some ways to be the most mature of the 

 five, ranks in the tests shown here from third to 

 fifth. And while M, the smallest, ranks low, she is 

 not the lowest, and other data show that in the per- 

 centage of her contacts which were self-initiated to 

 reactions she ranks first of all these sisters. 



These observed differences raise an interesting 

 question: If heredity has been the same and the 

 environment constant, how did the differences creep 

 in? It is possible that there are unobserved, unrec- 



