Peter Turchin

Peter Valentinovich Turchin (Пётр Валенти́нович Турчи́н; born 22 May 1957) is a Russian-American complexity scientist, specializing in an area of study he and his colleagues developed called cliodynamics—mathematical modeling and statistical analysis of the dynamics of historical societies.

Peter Turchin, Emeritus Professor at the University of Connecticut in the departments of Ecology and Evolutionary Biology, Anthropology, and Mathematics, is a project leader at the Complexity Science Hub Vienna and a research associate at the School of Anthropology of the University of Oxford.

He was Editor-in-Chief and remains member of the editorial board at Cliodynamics: The Journal of Quantitative History and Cultural Evolution.

Turchin is a founding director of the Seshat: Global History Databank.

He was a director of the Evolution Institute.

In 2021 he was elected Fellow of the American Association for the Advancement of Science.

Peter Turchin was born in 1957 in Obninsk, Russia, and in 1964 he moved with his family to Moscow.

In 1975 he enrolled at Moscow State University's Faculty of Biology and studied there until 1977, when his father, Soviet dissident Valentin Turchin, was exiled from the Soviet Union.

In 1980 Turchin received a B.A. (cum laude) in biology from New York University, and in 1985 a Ph.D. in zoology from Duke University.

Throughout his career Turchin has made contributions to various fields, such as economic history and historical dynamics.

He is one of the founders of cliodynamics, the scientific discipline at the intersection of historical macrosociology, cliometrics, and mathematical modeling of social processes.

Turchin developed an original theory explaining how large historical empires evolve by the mechanism of multilevel selection.

His research on secular cycles has contributed to our understanding of the collapse of complex societies as has his re-interpretation of Ibn Khaldun's notion of asabiyya as "collective solidarity".

One of Turchin's most prominent fields of research is his study of the hypothesis that population pressure causes increased warfare.

Turchin, in collaboration with Korotayev, has shown that negative results do not falsify the population-warfare hypothesis.

Population and warfare are dynamical variables.

If their interaction causes sustained oscillations, then we do not in general expect to find strong correlation between the two variables measured at the same time (that is, unlagged).

Turchin and Korotayev have explored mathematically what the dynamical patterns of interaction between population and warfare (focusing on internal warfare) might be in stateless and state societies.

Next, they tested the model predictions in several empirical case studies: early modern England, Han and Tang China, and the Roman Empire.

Their empirical results have supported the population-warfare theory: Turchin and Korotayev have found that there is a tendency for population numbers and internal warfare intensity to oscillate with the same period but shifted in phase (with warfare peaks following population peaks).

Furthermore, they have demonstrated that the rates of change of the two variables behave precisely as predicted by the theory: population rate of change is negatively affected by warfare intensity, while warfare rate of change is positively affected by population density.

In 2010 Turchin published research using 40 combined social indicators to predict that there would be worldwide social unrest in the 2020s.

He subsequently cited the success of Donald Trump's 2016 presidential campaign as evidence that "negative trends seem to be accelerating" and that there has been an "unprecedented collapse of social norms governing civilized discourse".

In 2020, Turchin and Jack Goldstone predicted that political and civic unrest in the United States would continue regardless of the party in power until a leader took action to reduce inequality and improve the social indicators that are tracked in their research.

Turchin has published over 200 scientific articles (including more than a dozen in Nature, Science, or PNAS) and at least eight books.

He is the founder of the journal, Cliodynamics, "...dedicated to 'the search for general principles explaining the functioning and dynamics of historical societies'", and manages a blog, Cliodynamica.