The Justinian Plague (Image:

This week at SFI, researchers take a quantitative look at an age-old question: to what extent is human history shaped by impersonal trends, big ideas, and great leaders?

“Historians have qualitatively debated the relative roles of these phenomena, and it’s clear all three have had some effect throughout history,” says SFI Professor David Wolpert, who is co-organizing the January working group with External Professor Manfred Laubichler (Arizona State University), Applied Complexity Fellow Michael Price, and Program Postdoctoral Fellow Hajime Shimao.

“We’re now at a point in time where we can begin to explore, quantitatively, which of these has been most important, and when,” Laubichler says.

Take the fall of Rome, for example — a complex collision of new ideas, such as Christianity; the cult of personality around Roman emperors; and impersonal plagues and population movements. Scholars have long argued about which of these many factors might have broken the empire’s back. Now, thanks to a bloom of new archaeological datasets, it may be possible to actually quantify how much each of these factors impacted the Mediterranean and Europe.

As an example of the type of research the group is pursuing, Price cites a recent paper on the Justinian Plague, published in PNAS. By amassing and analyzing archaeological evidence drawn from papyri, coins, inscriptions, and pollen, the paper’s authors were able to test popular claims that the pandemic, estimated to have spread between 540 and 750 CE, played a key role in the decline of the Roman Empire and the subsequent transition from antiquity to the middle ages. (Spoiler alert: it did not.)

The working group builds on previous SFI research into “Computational History,” “Big History,” and “Cliodynamics,” which seek to uncover mathematical patterns in human history to better understand its underlying dynamics. To that end, the group will be honing analytical tools from complexity science, such as time-series analysis, to crack open the “torrent” of historical and archaeological data that has been growing over the past two decades.

Read more about the working group, "The Interplay of Large-Scale Impersonal Trends, Big Ideas, and Great Leaders in History."