ABSTRACT
Dynamism must be one of the most salient characteristics of a family structure. The factors that contribute to this dynamism are two-fold: culture and time. There are many kinds of family structure around the world (e.g. monogamy, polygamy, nuclear family, extended family). The variety in family structure indicates that family structure strongly depends upon the type of culture. At the same time, family structure also depends upon the historical time course (Hatta et al., 1993; Hatta, 1994; Hasumi and Yamauchi, 1999). Even in the same culture, the influence of time (so-called Zeitgeist) on family structure is crucial. For example, the most popular family structure type in Japan before the second world war was the three-generation family; however, statistics from 1997 show that 58 per cent of the Japanese population now live in a nuclear family and that 25 per cent of people live alone. Three-generation families now account for only 11.2 per cent of the population (Japan Statistics Bureau, 1999).
