Every once and a while, there’s a little more tension in the group than usual. Fights break out more often, and when they do, they result in more injuries. But chimps have a mechanism for dealing with this tension.
After a big conflict last weekend, they’ve been working hard to reestablish their relationships through grooming.
Chances are, some of the wounds they are grooming on each other are wounds they themselves inflicted.
But that’s life for a chimp. You fight, and you make up. Then, maybe, you fight again.
But you always make up.