The shift to sedentary lifeways represents a significant change in human adaptation. Despite the broadly contemporaneous timing of this transition across East Asia during the Holocene Climatic Optimum, such changes varied regionally. This article synthesises new and existing data from Neolithic sites on the Mongolian Plateau to reveal a simultaneous shift towards investment in site architecture, with distinct variation in the organisation of settlement and subsistence across biogeographic zones. The development of sedentary communities here emphasises the importance of climatic amelioration for incipient sedentism, and demonstrates how differences in ecological and cultural contexts can encourage various responses to the same environmental stimuli.