This is a report of how the acceleration of growth correlates with urbanization for each Japanese prefecture. The secular trend in the age of maximum growth in height (MGA-H) was taken as an indicator of the acceleration of growth, and the ratio of workers in primary industries to the total number of workers (WPI-ratio) as an indicator of urbanization in general.
The results were as follows:
1) The greatest regional difference, an MGA-H of 1.59 years for boys and 0.87 years for girls, was observed for those born between 1947 and 1949. The regional difference may be due to the fact that the acceleration of growth has been shown greater in urban than in rural areas.
2) With boys, as the result of comparing the inflexion point computed out in each MGA-H curve, large regional differences were found between boys born in 1934 in Aichi, an urban prefecture, and boys born in 1957 in both Ehime and Miyazaki, typically rural prefectures.
3) The WPI-ratio has decreased yearly in relation to urbanization since World War II. In 1975, regional difference in ratios ranged from 0.7% in Tokyo to 34.9% in Iwate prefecture.
4) There were statistically significant positive correlations between the MGA-H of the same population plotted, for example, in 1934-41 (see Fig. 4) and the WPI-ratio of the same population 10 years later, except for the years immediately after World War II.
5) In analyzing the correlation coefficients between the WPI-ratio in 1955 and the MGA-H of each population by the year of birth, it became clear that the highest correlations were for boys born in 1941-43 (ages 12-14 in 1955) and for girls born in 1946-48 (ages 7-9 in 1955).
6) In some prefectures during the decade from 1955 to 1965, the greater the speed of industrialization, the greater the decline of MGA-H.
Judging from the fact that there are regional differences in MGA-H in some degree for each prefecture, it may be concluded that changes in the Japanese way of life along with urbanization are the main factors causing the acceleration of growth.
