"Monkey fights help explain tipping points in animal societies -" ScienceDaily

"Daniels, Krakauer, and Flack discovered that the distance from the critical point can be measured in terms of the "number of monkeys" that have to become agitated to push the system over the edge. Daniels says that in this system "agitating four or five individuals at a time can cause the system to destabilize and huge fights..."

https://www.sciencedaily.com/releases/2017/02/170210084537.htm