Archaeological study suggests inequality in human settlements dates back over 10,000 years

Economic inequality between the rich and poor may seem like a modern problem, but new archaeological evidence suggests it has existed for over 10,000 years.

A recent study published in the journal Proceedings of the National Academy of Sciences found that human settlements with greater material inequality tended to last for longer periods. However, the authors clarified that this correlation did not imply causation — inequality was not necessarily the reason for the longevity of these settlements.

“What we found is that, as humankind’s systems become larger and more complex, inequality has tended to increase alongside longer persistence. But the two are not mutually dependant, showing that humankind might be able to achieve sustainable persistence without the need for increased inequality,” Dan Lawrence, Department of Archaeology at Durham University, said in a statement.

Larger settlements within broader systems were generally both more persistent and more unequal, the study observed. “This suggests that urbanisation and the capacity to extract agricultural surplus and other forms of wealth from smaller rural sites enhanced persistence and increased material inequality at larger sites,” read the study.

The researchers examined whether inequality was an inevitable consequence of societal development, particularly in relation to sustainability. 

The United Nations defines sustainability as “meeting the needs of the present without compromising the ability of future generations to meet their own needs.” This definition includes both systemic continuity and social equity.

Scholars have reasoned that settlement persistence can be used a proxy for sustainability due to a theory that “a sustainable system is one which survives or persists.” However, the relationship between systemic continuity (human settlement persistence) and social equality two have not been investigated, the researchers stressed.

To explore this, the researchers analysed material inequality and persistence in a global dataset of archaeological settlements and covered data from over 2,990 archaeological sites around the world. 

“This paper is part of a larger study in which over 50,000 houses have been analysed to use differentials in house sizes as a metric for wealth inequality over time on six continents,” Gary Feinman, the MacArthur Curator of Mesoamerican, Central American and East Asian Anthropology at the Field Museum in Chicago and the paper’s lead author, said in a statement.

“This is an unprecedented data set in archaeology and it allows us to empirically and systematically look at patterns of inequality over time,” Feinman added.

Using statistical tools, Feinman and his team quantified and compared economic inequality in different places at different points in history. They calculated the Gini coefficient — a common measure of economic inequality ranging from 0 (perfect equality) to 1 (maximum inequality) — for each site. 

These coefficients were then compared across time and geography to detect long-term trends and their relationship to population size, political organisation and other potential causal factors.

While the study found that greater inequality was often associated with longer-lasting settlements, they argue that inequality is simply a necessary by-product of building complex, sustainable societies. The research also noted exceptions. Societies such as Monte Albán, Teotihuacan, Athens and Mohenjo-daro were large and long-lived, yet relatively egalitarian or equal.

The researchers argued that larger settlements were typically home to political power and institutions capable of extracting resources from surrounding rural areas through mechanisms such as taxation, tribute or tariffs. These urban centres also tended to serve as economic hubs, offering specialised services and goods unavailable in the hinterlands, they explained.

Evidence suggested that the residents of these urban centres got the most access to resources, particularly in regions such as Southwest Asia. Even in the Roman period, the concentration of military and state power may have enabled elite classes to build “consumer cities” by extracting rural surpluses on highly unequal terms, the study highlighted.

Nonetheless, the researchers stressed that there was no single explanation for how economic inequality emerged in different societies – but the analysis holds lessons on how to achieve a more equal and sustainable future. 

“We have shown that as past societies grow more complex and start to look more like our own highly urbanised and interconnected world, the two sides of sustainability, persistence and equality, can come into conflict. We argue that increasing extractive capacity for larger centres enhances survival prospects and raises material inequality at the same time,” the paper read.