Evolution of Social Complexity During the Shellmidden Period, the Central Ryukyus (amami and Okinawa Archipelagos), Japan: Not Simply Simple, but Not Necessarily Complex

Stratified societies in the form of chiefdoms emerged during the Gusuku Period (ca. late eleventh-fifteenth centuries) in the Central Ryukyus (Amami and Okinawa Archipelagos), Japan. They competed among themselves, and by the fifteenth century, the Ryukyu Kingdom had been established. In contrast, the social organization of the Shellmidden Period (ca. 7,000-1,000 BP), comprising huntergatherer-fishers (HGF), has been considered primarily egalitarian. Here we examine the development of social organizations during the Shellmidden Period finding that for the first several thousand years, populations were both mobile and egalitarian. However, more complex societies evolved during the Early 5 phase of the Early Shellmidden Period. The social organizations that developed between Early 5 and the end of the Shellmidden Period explicitly illustrate the cyclical nature or sawtooth-like pattern of social evolution, as we note repeated alternations between egalitarian and more complex societal forms, not all of which evolved into chiefdoms.