Ever get the feeling that you've seen it all before? University of Connecticut researcher Peter Turchin has, and he (along with Russian partners Sergey Nefedov and Andrey Korotayev) has even crafted an entire scientific theory around the idea. Cliodynamics, as it's called, works on the view that broad trends of history occur in predictable patterns based on common factors like government strength, population size and social inequality. The surprise to Turchin is that violence outside of wars, at least in the US, triggers roughly every 50 years like clockwork: people rebel against a social crisis, but their children stay out of the fray and lead to the conditions that ultimately trigger another outbreak, like the 1970s civil rights and peace movements. Don't set your watch to cliodynamics just yet. Many historians are still skeptical, and even supporters note that one-off events or major wars fall through the cracks. If the theory pans out, however, science could be used to help governments do the right thing before they're made to do it at gunpoint.
[Image credit: Steve Wilson, Flickr]