The Theory of Reciprocal Altruism

Bob Greene also pioneered the theory of reciprocal altruism which was the other gene-centered mechanism for explaining altruism. He says if you think that somebody is going to treat you well for treating them well it makes sense to behave that way. This then results in the possibility of having organized bands of individuals who are not narrowly calculating degrees of relatedness but can cooperate with people they aren't closely related to. It's one of the foundational elements of the grand theory of cooperation.