That sounds like they were just simulating the society based on data they had gathered about their fights. So not inducing monkey fights, just observing the mon

That sounds like they were just simulating the society based on data they had gathered about their fights. So not inducing monkey fights, just observing the monkeys fighting naturally and extrapolating from there. Though earlier in the article they allude to removing a few members of the society and showing the fights increased. Also it should be noted that fighting is a very common part of monkey behavior. If you observe these groups in the wild individuals are almost constantly challenging and checking others to maintain or advance their position in the social hierarchy.