BRAIN VOLUME AND MENTAL CAPACITY 435 



that the growth of the brain after birth is in some degree 

 proportionate to the extent to which it is used. But the degree of 

 intelligence achieved does not depend solely on capacity and 

 amount of experience. It depends also on the kind of experience. 

 An individual may acquire a false and foolish conception of his 

 total environment with as much toil as a true and wise one. 

 Mediaeval monks had on the average larger brains than their con- 

 temporaries, and the Chinese as a race have larger brains than most 

 races, but it does not follow necessarily that they were, or are, more 

 intelligent. The real problem, therefore, is not whether there is a 

 correlation between skull capacity and intellectual power, but whether 

 the capacity to develop a large brain is correlated to a capacity to 

 become exceptionally intelligent in one or more directions. 



716. The right conclusion to which the biometric facts, com- 

 bined with the rest that we know, lead us, appears to me, not that 

 the men who can develop large brains have on the average no 

 greater power of becoming intelligent than men who can only 

 develop small brains, but that the former may be worse trained 

 and therefore less intelligent. In other words, the biometrical 

 facts tend to demonstrate that right mental training is of as much 

 importance as capacity. 



