Child fostering as a reproductive strategy among Southern African pastoralists

Information on child fosterage was obtained on 1902 individuals in the course of collecting 611 reproductive histories from Herero and Mbanderu pastoralists in northwestern Botswana in southern Africa. The hypothesis that women foster out their children as a strategy for increasing the number of children they produce is tested. Analysis of these data indicate that sex and birth year of children and parents' marital status significantly influence a child's risk of being fostered, but the relationship of fostering to fertility is unclear. More recently born individuals, females, and children born to parents who were not married to each other are more likely to be fostered than older individuals, males, and children born to parents who were married to each other. A child's risk of being fostered does not appear to be influenced by mother's age if the parents were married to each other, while children born to parents who were not married to each other are more likely to be fostered if the mother is very young, but this pattern is not clear. No association between fostering and mortality was found.