There was a period of reduced mobility, increased population density, and social complexity among hunter–gatherers in northern Bothnian prehistory between about 4050 and 2050 cal BC. We argue that this was made possible by a combination of physical and social factors that include the shortening of the coastline due to isostatic land uplift, the reduction of distances between major river mouths along the Bothnian coast, and the local variability in rate of shoreline displacement at individual river mouths.
