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These results are based on an insufficient number of 

 cases to be really significant, but it is noteworthy that 

 they agree exactly with results obtained by Havelock 

 Ellis in his study of British genius. 1 Since the results 

 of these two studies are exactly the same in this respect, 

 there seems to be considerable justification for the con- 

 clusion that the facts observed in these few cases are 

 true in general, even though two mutually sustaining 

 studies based on comparatively few cases cannot be con- 

 sidered positive proof of the relation observed. 2 



If one assumes that the facts observed are evidence of 

 a universal condition, how is the phenomenon to be ex- 

 plained? It is difficult to imagine any way in which 

 these facts can be explained on physiological grounds. 

 On the other hand, the following hypothesis, based 

 on environmental influence, seems at least reasonable. 

 First-born and last-born children frequently enjoy greater 

 educational opportunity than do their intermediate broth- 

 ers and sisters. First-born often succeed in getting a start 

 before adversity befalls the family, or before the expense 

 of caring for an increasing family of young children 

 becomes so great that it is necessary to curtail the edu- 

 cation of some of the older children. On the other hand, 

 the last born of a poor family may be favored because, 

 as his older brothers and sisters become self-supporting, 

 it becomes relatively easy for his parents to keep him in 

 school. 



With this topic is concluded the discussion of the nine 

 environmental influences. Certain of Galton's proposi- 

 tions concerning the relation of nature and nurture 

 remain to be considered. 



1 Havelock Ellis, A Study of British Genius, ch. iv. 



2 For an opposing view, cf. Karl Pearson, On the Handicapping of 

 the First Born (London, 1914). 



