The world today is populated by large, sophisticated, densely populated, and technologically advanced nation-states. How did such complex social formations arise? Why do so many different states share so many features of governance and structure? Are there general principles of governing the evolution of human society that can explain these commonalities? Understanding how we got to our modern world is the critical first step in showing us where we are heading; a new article published in the Proceedings of the National Academy of Sciences offers new answers to these critical questions, taking a systematic, scientific look at how complex societies from around the world have developed over the last 10,000 years.

This work is the result of years of research conducted by a large, international team of evolutionary scientists, historians, archaeologists, and anthropologists led by Peter Turchin and Thomas Currie. The investigators systematically gathered historical information on c.400 different past societies from the last 10,000 years, sampling from 30 regions spanning the entire globe. Using sophisticated techniques of statistical analysis they were able to pinpoint a single dimension of 'social complexity' that can meaningfully measure the developmental trajectories of all societies explored in the sample. This single dimension is made up of 9 highly correlated characteristics (incorporating 51 separate features)—from the size of the society to its economic sophistication, administrative capacity, informational technology, and others.

While most previous studies focus on only one or two 'primary' characteristics to explain social development, this novel finding shows that social development requires an intricate co-evolution of numerous, seemingly disparate traits.

The data used in this project come from Seshat: Global History Databank, directed by Peter Turchin, Harvey Whitehouse, Pieter Francois, Thomas Currie, and Kevin Feeney. The Seshat project gathers information from past societies in order to rigorously test different hypotheses about the rise and fall of large-scale societies across the globe and human history. Seshat seeks to bring together in one place the largest collection of data on our shared human past ever assembled. Our findings highlight the power of the sciences and humanities working together to rigorously test hypotheses about general rules that may have shaped human history.

For further information about this research or the Seshat project, contact Jill Levine at All requests for interviews with Thomas Currie, Peter Turchin, or any of the article's co-authors should also be directed to Jill Levine.

About Seshat: Global History Databank: The Seshat: Global History Databank brings together the most current and comprehensive body of knowledge about human history in one place. Our unique Databank systematically collects what is currently known about the social and political organization of human societies and how civilizations have evolved over time. For more information on Seshat: Global History Databank visit or follow us on Facebook and Twitter (@seshatdatabank).

Acknowledgments. work on this project was supported by a John Templeton Foundation grant to the Evolution Institute, entitled "Axial-Age Religions and the Z-Curve of Human Egalitarianism," a Tricoastal Foundation grant to the Evolution Institute, entitled "The Deep Roots of the Modern World: The Cultural Evolution of Economic Growth and Political Stability," an ESRC Large Grant entitled "Ritual, Community, and Conflict" (REF RES-060-25-0085), an Advanced Grant from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme (grant agreement No. 694986), and a grant from the European Union’s Horizon 2020 research and innovation programme (grant agreement No 644055 [ALIGNED,]).

Read the PNAS article here.