Kinship Terms Used for 'Siblings' in Japanese

Kinship terms used for ‘siblings’ have been chosen as the forthcoming topic for making Linguistic Atlas of Asia and Africa. Based on the three criteria proposed by Matsumoto (2006) and Murdock (1968), terms for ‘siblings’ in Japanese are examined as the first step. The three criteria are distinctions of relative age, sex, and relative sex. Contemporary Japanese has a system of four words defined by distinctions of relative age and sex, while old Japanese had a system of two words defined by distinctions of relative age (‘elder sibling’ vs ‘younger sibling’) but also a system of three words defined by relative age and sex (‘elder brother’, ‘elder sister’, and ‘younger sibling’). Hachijo dialects have a system of three words defined by relative age and sex which is similar to that of Old Japanese. Ryukyu dialects have a system of four words combined by the system of relative sex, sex and relative age: the primary distinction is between ‘sibling of the same sex as Ego’ and ‘sibling of opposite sex’. How this complicated system is retained in Ryukyu dialects is examined based on the data from Zusetsu ryuukyu-go jiten (1981). The system of relative sex is mostly retained, while a system of two words defined by distinctions of relative age is being threatened by a system of three words defined by distinctions of relative age and sex.