Abstract
1) To testify Vinacke's hypothesis which assumed the parallel relationship between intelligence and conceptualization, six groups of feeble-minded children (IQ<80) graded in MA (4:0-9:0) were chosen as the subjects for the classification task of 20 picture-cards each representing some familiar object (e.g. an automobile) and the result was compared with that of the previous experiment in the same condition but in normal children (90<IQ<110) as subjects.
2) The responses of the chidren were, by the qualitative examination of the classification and the verbal expression of the classifying principle by the suject, divided into six categrories of which those belonged to the preconceptual stages were analyzed further.
3) The increase of the responses in the conceptual level with MA, was confirmed and the result was statistically significant, and, as to this tendency, there was no statical difference between the normal and the feeble-minded. Moreover, the successive order in which the various preconceptual responses became dominant with ascending MA, showed remarkable correspondence in both the normal and the feeble-minded group, suggesting a general developmental stages of the conceptualization.
4) Meanwhile the comparison with the normal in the weight of the various preconceptual response categories disclosed some qualitative characteristics of the feebleminded which were not identified by MA as the quantitative, statistical concept; e.g. their stand still mental state, their primitive mentality in contrast to higher CA, and the dominancy of the mechanical verbal habit unsupported by the proper conceptualization.
