The hypothesis of animal interactions, known as kin selection or the selfish gene, proposes that only blood relatives are capable of forming herds and engaging in unselfish acts with each other. While this may satisfy the expectations of many evolutionists, the animals themselves frequently do not adhere to this restriction. There are several examples of animals in the wild assisting unrelated individuals at a cost to themselves and many also form colonies that contain unrelated individuals. In this monograph the author proposes a modification to the theory that renders the restriction of kin selection altogether unnecessary. Instead, he argues that the genes of animals that control social interactions, do not give instructions at all, but nudge the animals through combinations of rewards and penalties towards their best long-term interests in accord with the principles of Darwinian evolution. This exposition has been built on the many excellent published observations and experiments of researchers in the field and in the laboratory. It accounts for all general types of sociality of animals and humans including passive sociality, social exchange, sexual segregation, dispersal, adoption, mutual support, cooperation, altruism and human homosexuality....

Anthony Caswell was a long-term professor and researcher at the University of Miami Medical School. He now lives in North Georgia.