A considerable body of evidence has now demonstrated positive correlations between
grandparental presence and child health outcomes. It is typically assumed that such
correlations exist because grandparental investment in their grandchildren improves child
health and wellbeing. However, less is known about how grandparents allocate help to
adult children and grandchildren, particularly in lower income contexts. Here we use
detailed quantitative data from the longitudinal Indonesia Family Life Survey (data
collected in 1993, 1997, 2000, 2007; n=16,250) to examine grandparental help in a society
transitioning both demographically and economically. We test the hypothesis that
grandparents direct help preferentially towards those adult children and grandchildren
most in need of help. This hypothesis was supported for help provided by married
grandparents and single grandmothers, who tended to: provide more help to their adult
children when this generation had young children themselves, provide financial help if
their adult children were poorer, and provide more household help if their adult daughters
worked outside the home. One unexpected result was that help from maternal and paternal
grandparents is positively correlated; if one set of grandparents is helping the other set is
more likely to help, counter to our predictions. These results provide support for the
hypothesis that grandparents preferentially invest in some descendants over others, where
married grandparents and single grandmothers tend to invest in those adult children and
grandchildren with the most need. Investigating the effect of grandparents on child health
outcomes may therefore be confounded by grandparent’s preferential investment in
needier descendants.