Archaeologists discover historical link between inequality and sustainability
Durham University
The study lead by Professor Dan Lawrence, of Durham University in the UK, found that across ten millennia, more unequal distributions of wealth correlated with longer-term human settlement.
However, the team are keen to stress that one factor is not causally dependent on the other, giving hope that humankind’s survival is not linked to ever increasing inequality.
The research is part of a Special Feature of the Proceedings of the National Academy of Sciences (PNAS), entitled Global Dynamics of Wealth Inequality.
Sustainability is defined by the UN as ‘meeting the needs of the present without compromising the ability of future generations to meet their own needs’. The study investigated the relationship the two key aspects of this definition, continuity and equality.
The team used data on house size from across the world, covering the last 10,000 years, analysing records of over 47,500 homes across over 2,990 archaeological sites.
Differences in house size were used as a measure of inequality during different time periods. This data was then analysed alongside information on the duration of occupation, in simple terms how long people lived in a settlement before it was abandoned.
The findings revealed a correlation between the two measures – with more unequal settlements (as measured through house sizes) tending to persist for longer. However, this relationship was not found to be causal, and instead both factors rose with the increased scale and complexity of human systems.
The research team believe the findings could help inform interventions to improve future sustainability.
Speaking about the research, Professor Dan Lawrence, Department of Archaeology at Durham University said: “The UN definition of sustainability references our societies not only continuing to exist but becoming more equal.
“We wanted to understand the relationship between those two aspects and ask whether equality or inequality is historically more sustainable.
“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.
“It is not the case that inequality is simply a necessary by-product of building complex, sustainable societies.
“We need to be aware of, and attentive to the historical interplay between inequality and sustainability.
“At a time of ever-increasing wealth inequality and sustainability challenges including climate change, the lessons from the past 10,000 years could be invaluable for helping us to achieve a more equal, truly sustainable future.”
The study was authored by researchers from across Europe and the USA, drawing on a database collected by archaeologists from across the world. It is published as part of a special feature of PNAS, which has examined the origins and drivers of inequality from multiple angles.
Each of the studies has utilised a specially compiled data set on house sizes across the world from the last 10,000 years, as well as information on societies across time, such as structures, hierarchies, agriculture etc.
Professor Dan Lawrence, Department of Archaeology, Durham, has also been co-author on eight other papers as part of this special feature.
ENDS
Journal
Proceedings of the National Academy of Sciences
Method of Research
Data/statistical analysis
Subject of Research
Not applicable
Article Title
Housing inequality and settlement persistence are associated across the archaeological record
Article Publication Date
14-Apr-2025
PULLMAN, Wash. — Wealth inequality began shaping human societies more than 10,000 years ago, long before the rise of ancient empires or the invention of writing.
That’s according to a new study led by Washington State University archaeologist Tim Kohler that challenges traditional views that disparities in wealth emerged suddenly with large civilizations like Egypt or Mesopotamia. The research is part of a special issue of the Proceedings of the National Academy of Sciences, co-edited by Kohler and Amy Bogaard, an archaeologist at Oxford University in England.
Drawing on data from over 47,000 residential structures across 1,100 archaeological sites worldwide, the researchers used house sizes as a measure of wealth. Their analysis shows that wealth inequality started to increase roughly 1,500 years after the advent of agriculture in different civilizations across the world. This effect was driven by population growth, competition for land and the development of hierarchical settlements.
“Many people imagine early societies as egalitarian, but our research shows wealth inequality took root surprisingly early,” said Kohler. “The shift wasn’t instantaneous. It grew gradually as societies expanded, populations increased and resources became more constrained.”
The study highlights several key factors contributing to inequality. As farming communities grew, land became a finite resource, leading to competition and innovations like terracing and irrigation to boost productivity. Over time, larger settlements emerged as hubs of economic and political activity, where wealth began to concentrate in the hands of a few households. These wealth disparities were particularly evident in high population settlements, which exhibited greater inequality than smaller communities.
Tim Kohler
One of the study’s significant revelations is that wealth inequality predates written records, with evidence showing disparities existed even in the earliest agricultural societies. By applying the Gini coefficient—a standard measure of inequality—to ancient house sizes, researchers discovered that early farming villages were relatively egalitarian. However, as settlements became larger and more complex, economic disparities grew.
The study also challenges the idea that preindustrial societies lived in a “Malthusian world” of subsistence-level existence. Instead, Kohler and his team found evidence of steady wealth accumulation and technological advancements over millennia. The researchers point out that early agricultural societies often modified their landscapes—building terraces, draining wetlands, or creating irrigation systems—to intensify production. These innovations increased productivity but also widened the gap between those who controlled resources and those who did not.
Interestingly, the research revealed that some innovations, like iron smelting, often reduced inequality by increasing access to tools and resources for lower social strata. This finding challenges the assumption that technological advances always benefit elites. Kohler also noted that other factors, like the presence of large governing systems or collaborative social networks, played a role in mitigating or amplifying inequality over time.
“This isn’t just a modern problem,” Kohler said. “Understanding the origins of wealth inequality helps us see it as a persistent challenge that societies have been grappling with for thousands of years. The past has much to teach us about navigating these issues today.”
The study was a collaborative effort involving 27 researchers from institutions worldwide and was coordinated by the Coalition for Archaeological Synthesis, a not-for-profit organization dedicated to synthesizing the archaeological record to advance science and benefit society. By focusing on the period before written records, the researchers hope to fill a critical gap in understanding how human societies evolved, from egalitarian hunter-gatherer groups to complex, hierarchical communities.
“These patterns are deeply embedded in our history,” Kohler said. “But by studying them, we can better address their implications for the future. If we can understand how inequality emerged and evolved, perhaps we can learn how to mitigate its impact today.”
Journal
Proceedings of the National Academy of Sciences
Article Title
Economic inequality is fueled by population scale, land-limited production, and settlement hierarchies across the archaeological record
Article Publication Date
14-Apr-2025
Jan 15, 2018 ... Debt: The First 5000 Years is a book by anthropologist David Graeber, published in 2011. It explores the historical relationship of debt ...
