Background/Question/Methods The two fundamental bases of demography are fertility and mortality: everyone is born, and everyone dies. The third fundament is family and kinship. In many species, especially those with social structure and extended parental care, everyone is born with some kind of family and set of kin. However, there has been no generally applicable formal demographic framework for analyzing kinship. This talk will present such a framework. The goal is to produce a set of calculations that apply equally to age- and stage-structured populations and that can easily compute the age-stage distributions of the kin (of any kind) of an individual of any age. Results/Conclusions The desired framework is obtained as a coupled system of non-autonomous matrix difference equations. These equations, it will be shown, treat the kin, of any kind, of any individual as a population. This populations is projected forward in time on the basis of mortality and the fertility of other kinds of kin (e.g., the production of new grandchildren is due to the fertiity of children). Because kinship plays a key role in inter-generational relationships and kin selection, these results open up standard demographic studies to the inclusion of kinship calculations.
