Why do civilizations collapse? New study points to the risks of aging

How states and civilizations rise and fall has been an enigma that has puzzled historians for years. An analysis of hundreds of ancient and medieval societies reveals that they become more fragile as they age.

Triggers of societal collapse have been well studied and vary from conquest and coups to earthquakes and droughts. This new study shows that pre-modern states faced a steeply increasing risk of collapse within the first two centuries after they formed. The research identifies several mechanisms that could drive these aging effects. Some of the mechanisms, like environmental degradation and growing economic inequality, are still at work today.


The findings, published in the Proceedings of the National Academy of Sciences, highlight the need to understand internal processes that may contribute to the demise of states. The study, which holds implications for the modern world, provides the first quantitative support for the theory that the resilience of political states decreases over time.

During the course of the 15th century, nearly all of Angkor was abandoned. Photo by Dudva / Wikimedia Commons

The researchers looked at this question from a new angle, by analyzing longevity in 324 pre-modern states spanning five millennia. “This approach is commonly used to study the risk of death in aging humans, but nobody had the idea to look at societies this way,” says Marten Scheffer of Wageningen University, lead author of the study.


In humans, the risk of dying doubles approximately every 6-7 years after infancy. As that exponential process compounds with great age, few people survive more than 100 years. The authors show that it works differently for states. Their risk of termination rises steeply over the first two centuries but then levels off, allowing a few to persist much longer than usual.

During these first two centuries, civilizations will likely encounter major problems. The authors point out some of the main issues:

Over time, environmental degradation (e.g., deforestation, soil erosion, and salinization) and growing population numbers may lead to scarcity. Also, disease risks may rise in increasingly crowded settings. In addition, there is a tendency for wealth to fall increasingly into the hands of a small elite, causing a rising gulf between elites and the rest. This can lead to heightening corruption and poorer decision-making and to the exacerbation of a range of social ills, including interpersonal violence. Poor decision-making refers to choices which benefit the elite rather than the public and that are less responsive to impending challenges and risks. Increasing population and elite numbers coupled with declining real or relative wages could also generate civil strife and breakdown. Lastly, the overhead costs of growing societal complexity may drain resources.

Sack of Rome. 6 May 1527. By Martin van Heemskerck in 1527.

The researchers found a similar pattern all over the world from European pre-modern societies to early civilizations in the Americas to Chinese dynasties.


“Ancient Chinese states or dynasties had an upper limit of longevity around 300 years across the past two millennia. This middle-school textbook knowledge in China has a myriad of explanations, but no consensus has been reached,” says co-author Chi Xu of Nanjing University in China. “Perhaps the answer is underneath the global pattern of human civilizations — what happened in ancient China is a perfect reflection that all societies will age and become vulnerable.”

The 324 states and civilizations included in this study existed between the years 2000 BCE and 1800 CE. While many medieval states were included, the authors rejected several for different reasons. With Venice and Pisa, they were considered city-states. The Srivijaya Empire, based out of India, based its power on control of trade routes rather than land. As for the Papal States, the authors write:

It does appear to be a state (theocracy) with a form of taxation over multiple territories, albeit with highly decentralized governance. However, it is a border case and given multiple periods of schism (including times when territories fell more under the control of Roman nobility than the papacy) we have decided to exclude it.


Societies today differ in many ways from the pre-modern states studied by the authors. Nonetheless, according to Scheffer, humans should not expect modern societies to be immune to the mechanisms that drove the waxing and waning of states for thousands of years.

“Mechanisms that destabilized past societies remain relevant today,” Sheffer says. “Indeed, perceived unfairness and scarcity exacerbated by climatic extremes may still drive discontent and violence.”

Current threats to global society make these findings particularly applicable, adds co-author Tim Lenton from the University of Exeter.

“As our society enters a climate and ecological crisis of our own making the evidence that it is getting less resilient just increases the systemic and existential risks we are facing,” he says. “A glimmer of hope is that some past societies pulled through crises and lived much longer — but they had to reinvent themselves in the process.”


The article, “The vulnerability of aging states: A survival analysis across premodern societies,” by Marten Scheffer, Egbert H. van Nes, Luke Kemp and Chi Xu, is published in Proceedings of the National Academy of Sciences. Click here to read it.