The utility of an action declines from an inclusive fitness perspective as a of the coefficient of relatedness between an actor and the recipient of an action.

In other words, the less well an is to another then the less of a Darwinian fitness boost that can be achieved by helping that other individual, at least as viewed in terms of kin selection.

Also relevant is the cost of the action as well as the number of related individuals that benefit from a single action. In a formal as well as simplified form, Hamilton's Rule embodies many of these ideas:

     rB > C

where r is the coefficient of relatedness, B is the benefit received, and C is the cost to the actor (i.e., the ).

If this inequality holds, then an altruistic act can be viewed as beneficial to any underlying alleles and therefore may be deemed to be positive in terms of its impact on the inclusive fitness associated with those alleles.

See also .