Historically, the help provided by grandmothers has increased grandchild survival during times of high child mortality. However, there have been signs that in many populations, the impact of maternal grandmothers and paternal grandmothers on their grandchildren has been different. A recent study conducted at the University of Turku, Finland, shows that X-chromosome relatedness between grandmothers and their grandchildren did not affect grandchild survival in 18th- and 19th-century Finland.