Surely the conditions that lead to insurgency and war depend upon such things as ideology, anger, the desire for revenge and other factors unique to each location, to each insurgent group, to each mortal conflict. Johnson and his colleagues, experts in the modeling and understanding of complex systems, weren’t buying that assumption. They reviewed 11 very different conflicts and concluded that the size and timing of violent events across these conflicts showed “remarkable” similarities. Oddly, they found that this behavior resembles, in many ways, the behavior of financial markets. “We found that the way in which humans do insurgent wars—that is, the number of casualties and the timing of events—is universal,” Johnson says. He says that the model “can predict changes in likelihood of an attack” and how many people it’s likely to kill. Skeptical? He will do his best to persuade you.