In some populations of babouins there is a good custom. When two males of approximately equal hierarchical position engage in some common affair (usually it is an attack on a high-ranking male, or a joint production of food, etc.).There is always a risk that they will cross each other along the way. When their position in the hierarchy of the herd is clearly different, and it is obvious for both of them who is the chief here, then there is no problem. But when they are equal competitors, conflict is very likely. And in this case, a special "ritual of invitation to cooperation" has been developed in some communities. They come together and catch each other’s eggs. And squeeze a little, but so that it doesn’t hurt, because if you give in to the temptation and seriously drag, then you have to remember that he holds your testicles in your fist too. This custom removes potential hostility and makes males for some time capable of mutually beneficial joint actions. This is how a strong friendship is born.