Cycles of Violence in the United States
Stephen Johnson about Peter Turchin's Cliodynamics:
"In his 2012 study, Turchin examined the history of sociopolitical instability in the U.S. from 1780 to 2010. To do this, he used data on about 1,600 violent political incidents from American history, such as lynchings, riots, and terrorism.
He combined that data with a model that factored in broader societal forces, such as falling wages, wealth inequality, changes in population, and increased competition for elite jobs.
The results revealed that American political violence tends to occur in regular cycles, with valleys of peace punctuated by peaks of violence and unrest.
US Political Violence Database chart showing spikes in 1870, 1920, and 1970.
One is a short cycle that occurs about every 50 years, with peaks in 1870, 1920 and 1970. Turchin calls this oscillation the "father-son" cycle: the father perceives a social injustice and revolts, while the son's generation deals with the aftermath and abstains from revolution. Then, the third generation repeats the cycle.
The second cycle is much longer, peaking once every two to three centuries. The cycle begins with a society that's roughly egalitarian, but over time its population increases, labor supply outpaces demand, and wealth inequality becomes increasingly intolerable. Eventually, societies tend to collapse or suffer widespread political instability." (https://bigthink.com/politics-current-affairs/2020-predictions?)