Sometimes, history really does seem to repeat itself. After the US Civil War, for example, a wave of urban violence fuelled by ethnic and class resentment swept across the country, peaking in about 1870. Internal strife spiked again in around 1920, when race riots, workers’ strikes and a surge of anti-Communist feeling led many people to think that revolution was imminent. And in around 1970, unrest crested once more, with violent student demonstrations, political assassinations, riots and terrorism (see ‘Cycles of violence‘).
To Peter Turchin, who studies population dynamics at the University of Connecticut in Storrs, the appearance of three peaks of political instability at roughly 50-year intervals is not a coincidence. For the past 15 years, Turchin has been taking the mathematical techniques that once allowed him to track predator–prey cycles in forest ecosystems, and applying them to human history. He has analysed historical records on economic activity, demographic trends and outbursts of violence in the United States, and has come to the conclusion that a new wave of internal strife is already on its way1. The peak should occur in about 2020, he says, and will probably be at least as high as the one in around 1970. “I hope it won’t be as bad as 1870,” he adds.
Read more at Nature