In the present study, I investigated 15, 604 infants by means of a check list of approximately thirty items in order to find the standard tendency of the development of infants. For each observed item the development was shown by a percentile curve. The results, on the whole, corresponded with the already standardized tendency of infant development in Japan. During the period of infancy which is considered to be the first “twist” or distortion in the course of human development, there were found four representative phases in which several typical gross activities were observable. They are, namely, the first period (4.7mos.-5.8mos.), the second (7.9mos.-8.2mos.), the third (9.4mos.-10.2mos.), and the fourth period (11.0mos.-12.0mos.). It is hard to find an appropriate designation to characterize those periods. They take somewhat the forms of “plateaus” in the learning curve. The tendencies of those periods will be fully discussed in the next report.
The purpose of this research is to clarify the factorial structure of the verbal abilities expressed in terms of educational objectives in the course of Japanese. Two groups of subjects were used for the analyses; the one consisted of 120 senior high school pupils, and the other consisted of 120 junior high school pupils. Ten verbal variables in the field of written language were obtained from the first group, while fifteen from the second. The scores were correlated among each group, and the matrices were analysed by means of group factor analysis. The first group was analysed into a pattern which has one general factor G and two group factors named K and U respectively. From the second group, too, we obtained one general factor G and two group factors named V and E respectively. The V was sub-analysed into K and U, while the E, too, produced another significant sub-factor C. It is inferred that there might be no significant difference between the two factor patterns so far as the ten variables used in common were concerned. To examine further the developmental differentiation, however, more groups of pupils covering wider range of age are to be employed. Factor V, which has been analysed from the second group, is chiefly concerned with abilities of verbal comprehension in a broad sense, the nature of which is similar to the historically well-known V factor. The K which has been derived from V (or directly from G in case of the first group) is a factor of word knowledge, while the U is to be interpreted as one of pure verbal understanding, such as catching the meanings or general ideas of written statements. Factor E, which is contrasted to V in the second group, obviously shows an expressional power, because it is chiefly correlated with the variables of writing and describing. The last C may be considered to represent creativeness, for the two variables concerning sentence construction and composition are highly loaded on it. The present data can thus demonstrate the existence of sub-divisional group factors in the realm of verbal abilities expressed in terms of educational objectives. However, in order to give more reasonable and convincing interpretations on the psychological natures of the factors, it is hoped that more comprehensive analyses be carried out with many other pertinent variables added.