Reciprocal altruism is a fascinating phenomenon in the world of social behaviour. It refers to the idea that humans and animals tend to exhibit altruistic behaviour in which they help others without directly benefiting from it, with the expectation that this help will be returned later. This concept is closely linked to the 'tit-for-tat' principle.

Reciprocal altruism is widespread in the animal world. A classic example of this is birds helping each other preen their feathers. Although this act of helping takes time and energy, the birds can later expect their mates to help them when they need it. This behaviour increases the chances of survival of the group as a whole.

In humans, reciprocal altruism manifests itself in many ways. A simple example is the sharing of resources. If someone lends money to a friend without expecting anything in return immediately, this is based on the principle of reciprocal altruism. The friend could help later in a similar situation.

It is important to note that reciprocal altruism is not always conscious or calculated. People often act out of an instinctive feeling to help others without having a clear idea of when or how the help will be returned. This behaviour is an important part of social bonds and cooperation.

Another related concept is the "Golden Rule", which states: "Do unto others as you would have them do unto you". This principle also reflects the idea of reciprocal altruism, as it aims to provide others with the same goodwill and help that you would like to receive yourself.

In summary, reciprocal altruism is a deeply rooted pattern of social behaviour that occurs in many aspects of human life and in the animal world. It promotes co-operation, social bonding and group survival by encouraging give and take in a balanced way.