Pearl, Intelligence and Size of Head. 199 



the association between vigor in growth processes (leading to a 

 well-developed body) and vigor in mental processes would most 

 probably be the result of the action of good conditions of nurture. 

 Other things being equal groups of men with well-nourished 

 bodies are on the average likely to be more able intellectually than 

 groups in which bad conditions of nutrition prevail. Such an 

 interpretation of the facts seems at present to have much better 

 justification than any which in effect implies that a big brain con- 

 notes per se an able mind. 



Rightly interpreted the facts regarding the correlation between 

 size of head and intelligence seem to me simply to furnish, so far 

 as they go, direct statistical evidence in favor of the adage: Mens 

 Sana tn corpore sano. 



