Interaction with People other than Family Members. The last control variable measures an individual’s degree of socialization with non-family people. In this study, the degree of socialization is estimated using the minimum number of non-family people that an individual interacts with on a typical day. Table 1 shows that samples in this study interact with 12.4 people outside their family on a typical day on average. Males tend to perform more social interaction than females, socializing with 13.6 people on average per day. Females socialize with 11.3 people on average. Previous studies also show a sharp decrease in arranged marriages and surge in love marriages since 1982. In 2010, nearly 88% of the marriages among couples with the wife under 50 years old in Japan were love marriage (IPSS, 2011). In a modern society with increasing love marriages such as Japan, individuals’ degree of interaction with other people provides them the opportunity to expand their social network. Although the fast development of new communication media such as internet and cell-phones has provided alternatives for direct socialization, face-to-face interactions are still crucial for development of romantic relationships.
