News release

From: The Royal Society

When the going gets tough – You don’t get much more loyal than a maternal grandmother – even in the face of adverse early life experiences. English and Welsh students aged 11-16 filled in questionnaires to assess their adverse early life experiences (e.g death of a family member, financial difficulties, parental separation) and grandparental investment. It found that when grandchildren experienced more adverse early life events, paternal grandparents had lower investment, while maternal grandparents, particularly grandmothers, continued to invest.

Matrilateral bias of grandparental investment in grandchildren persists despite the grandchildren’s adverse early life experiences

Proceedings of the Royal Society B: Biological Sciences

This study suggests that maternal grandparents, and maternal grandmothers in particular, keep investing in their non-co-residing grandchildren despite the adverse early life events (e.g. death of a family member, financial difficulties, parental separation etc.) experienced by the grandchild. On the other hand, paternal grandparents showed diminished investment in grandchildren when the number of adverse early life events in grandchildren increased. This finding is in line with the evolutionary prediction that the potential reduction in the reproductive value of offspring (i.e. the fraction of a future population descending from them) growing up in adverse environments may influence grandparents' investment.