Human social complexity was significantly lower during climate cooling events of the past 10 millennia

Abstract

Human civilizations depend on the climate. Changes in climate affect the production of food and other resources that support populations and their economies. We asked whether the millennium-scale climate cooling events identified by Gerard Bond predicted social complexity in the Seshat cross-cultural database. The results show that social complexity was significantly lower during the coldest two centuries of Bond cooling events. Reductions in complexity are evident in regions north of the tropics adjacent to the Atlantic or Arctic, particularly in North Africa, Europe, and Central Eurasia.

Keywords

• social complexity
• bond event
• climate
• historical ecology