The Genetical Evolution of Social Behavior. I.
A genetical mathematical model is described which allows for interactions between relatives on one another’s fitness. Making use of Wright’s Coefficient of Relationship as the measure of the proportion of replica genes in a relative, a quantity is found which incorporates the maximizing property of Darwinian fitness. This quantity is named “inclusive fitness.” Species following the model should tend to evolve behavior such that each organism appears to be attempting to maximize its inclusive fitness. This implies a limited restraint on selfish competitive behavior and possibility of limited self-sacrifices.