Reciprocity (evolution)

Reciprocity is a way of exchanging favors and help between two people. In evolution, it is a way for animals to get benefits from each other. For example, if a bird wants to get food from another bird, it might help the other bird first by bringing it food or by helping it build its nest. After the first bird helps the second bird, the second bird might be more willing to help the first bird in return. This way, both birds can benefit from each other and become closer friends.