Factors influencing the frequency of consanguineous marriages in Japan

Abstract

A survey of consanguineous marriages in Japan was conducted through questionnaires in 1983. The total number of couples studied was 9225, chosen from 6 widely different areas of Japan. The rates of first cousin marriages and of total consanguineous marriages for all areas were 1.6% and 3.9%, respectively. The rate of total consanguineous marriages was 10 times higher in Fukue-Shi (7.9%) than Asahikawa city area (.78%). The rate of total consanguineous marriages decreased with the marriage year in Japan, where the rate of first cousin marriages has changed remarkably. The rates of consanguineous marriages were estimated according to marital distance between birth places, socioeconomic classes, religion, marriage form, opportunity of encounter, and motivation towards marriage. Among educational groups, the rate was highest in graduates of junior high school for husbands and wives, and the rate was lowest in college or university graduates. Occupationally, the rate was the highest in agriculture, forestry, and fishery for husbands and wives, and the rate was lowest among salesmen for husbands and in professional occupations and researchers for wives. As for opportunities of encounter, the rate was 22-29 times higher in the group for friendship from the time of childhood (25.8%) than in those for school, workplace, and social gatherings (1.2%) and for chance meetings (.9%). A recommendation by parents and relatives was the most frequent reason for consanguineous marriage for both husbands and wives, followed by knowledge of the partner by relatives.