As those societies developed, people adopted similar beliefs and rituals, took up new ways of farming and architecture and and fell into a more organized social structure, Bocinsky said.

That lasted until a prolonged drought or other climate catastrophe hit the area, causing the failure of corn crops, a main food source for the population. Drought would have undermined people’s beliefs in ritual structures because those were thought to be sustaining the corn-growing conditions, Bocinsky said.

“When that went south, it undermined the credibility of that system,” he said.

At that point people would begin to disperse in search of better growing conditions and new ways of living, indicated by a drop in the frequency of cut wood samples across the region, Bocinsky said. After several decades, people would again find and settle on better ways of living, evidenced by things like different maize storage techniques and architectural styles, and begin to unify under a common system and the pattern would repeat again, he said.

Peaks and Valleys