Evolutionary limits to self- preservation

A simple mathematical formula can be derived, on the basis of inclusive fitness theory and notions of reproductive value, to represent the residual capacity of an individual to influence his inclusive fitness. This formula involves the individual's remaining reproductive potential in his expected natural lifetime, plus the summated impacts of his continued existence on the remaining reproductive potentials of each of his kin, each weighted by the coefficient of relationship. In theory, this quantity should predict the extent to which self-preservation is optimally expressed in that individual. For asocial species, the value will vary from zero up to the maximal reproductive value observable, and the logic of the Medawar-Williams theory of senescence should apply directly. However, for highly social species like our own, it can be demonstrated that negative values can also obtain, given the conjunction of low residual reproductive potential and burdensomeness toward kin. Much empirical evidence suggests that outright self-destructiveness is often found in circumstances of such conjunction.