THE METHOD OF AGE GRADATION 73 



whereas the levels 10 to 12, taken together, com- 

 prised only 7 per cent, of the total number. Though 

 here, again, he unfortunately put together those 

 children whose age was such that they might per- 

 haps have been able later to transcend the level in 

 which they were then found and the other inmates 

 whose development had for ]ong been completely 

 checked, yet his results do at least demonstrate that 

 the feeble-minded only rarely transcend the mental 

 age of nine. 



By comparing these mental ages with the diag- 

 noses of the physicians he arrived at the following 

 schema : 



, Imbeciles x 



Low- Middle- High- 

 Type Idiots grade grade grade Morons 

 Mental ages 1 to 2 3 to 4 5 6 to 7 8 to 12 



Goddard's ' morons' coincide with our ' mentally 

 feeble' (Debilen). The figures just given show that 

 by far the greater number of them have a mental age 

 of 8 and 9 years. 



Kramer (54, p. 29) and Chotzen (44, p. 494) 

 reached similar results. 



Goddard compared the experimentally determined 

 mental age with the general impression that the 

 children had made on the teachers and officers of 

 the institution and found a very satisfying amount 

 of agreement. The children of a given mental age 

 formed a fairly homogeneous group, both in respect 

 to their every-day accomplishments and their ability 

 to adapt themselves to the demands of institutional 

 life. He adds to this a description of what can be 

 expected in the line of practical behavior of a child 



