8b PSYCHOLOGICAL METHODS OF TESTING INTELLIGENCE 



words we may say that the 'hits' and * misses' of the 

 older feeble-minded children are scattered over very 

 many more age-levels than are those of younger 

 normal children : the defective fails unexpectedly to 

 pass some quite easy tests, but succeeds here and 

 there in meeting much higher requirements. There 

 appears a certain dissociation of abilities that are 

 normally more strictly intercorrelated. 



We are now in a position, moreover, to discover 

 a general principle obtaining in this dissociation. 

 There are certain abilities that are essentially a 

 function of age, relatively independent of intelli- 

 gence: there are other abilities that are conditioned 

 entirely ~by specific degrees of intellectual develop- 

 ment, regardless of the age at which this develop- 

 ment is attained. A child of 9 or 10 years of age, 

 even if he be defective, will be farther advanced than 

 a normal child of 6 or 7 years of age in abilities of 

 the first sort; but a normal child necessarily sur- 

 passes a feeble-minded child in abilities of the second 

 sort. 



A priori we should expect that to the first sort of 

 abilities (those conditioned by age) would belong 

 those dependent upon a mass of experiences fre- 

 quently had and activities frequently discharged in 

 everyday life. But a priori opinions of this sort are 

 of no great service to us, and it will be of corre- 

 spondingly great value for us to be able to discover 

 by an analysis of the results of Binet-Simon tests 

 which of the tests applied to the feeble-minded cor- 

 relate more with age and which more with real in- 

 telligence. Up to now the results of Chotzen are 

 alone available for this purpose and even they af- 



