Although the correlation between climate and crop yield is an acceptable hypothesis for populations whose sanitary conditions were very poor (with, for example, anemia linked to parasitosis), a worsening climate with short, rainy summers increases the risk of poor harvests and famine. In bad times such as these, population densities fall.
On the other hand, when the climate improves, renewed demographic growth in the most fertile regions causes some marginal groups to leave and colonize less-populated areas. This would explain how new contacts were quickly made with groups beyond the immediate vicinity. The expansion of certain groups from the area of southern Ferrières resulted in ornamental objects being traded or imitated up to 400 kilometers from their place of origin.
Circular limestone beads and bladed pendants.
Chalain, previous excavations.
Archaeological Museum, Lons-le-Saunier.
Steatite (talc) beads and pointed pendants.
Clairvaux, station IV, 31st century BCE.
Geographic distribution of bladed pendants.