Power and exclusivity. In chimps, exclusive bonds are tools for political advancement. Betrayal is common. This forces us to ask: is exclusive fidelity in humans a moral choice, or is it similarly conditional on perceived benefits?

In Gombe Stream National Park, Jane Goodall documented a famous exclusive alliance between two males, Humphrey and Charlie. Together, they overthrew the alpha male. After Humphrey became alpha, he maintained exclusive grooming with Charlie, but when Charlie was injured, Humphrey replaced him with a younger male. The relationship was conditional exclusivity —loyal until one partner lost value.