Family matters : kin, demography and child health in a rural Gambian population.

Abstract

In this study, we focus on a traditional society, and assume inclusive fitness arguments largely provide an explanation for allocare. Hamilton's rule states that help will be provided to recipients by their relatives, provided that the costs of helping are less than the benefits to the recipient, discounted by the degree of relatedness between recipient and donor: rb>c where r represents the coefficient of relatedness (the probability that any gene will be shared by recipient and donor), b the benefits of helping and c the costs. For allocare to become common between a given set of relatives, the benefits of allocare (b) must be relatively high, the costs (c) relatively low, or both.