1Department of Anthropology, Humboldt State University, 2Windward Islands Research and Education Foundation, Grenada, West Indies
Saturday All day, Plaza Level
The ‘grandmother hypothesis’ proposes that the adaptive advantage for post-menopausal longevity in humans is the presence of grandmothers to provide high quality care for grandchildren, resulting in improved reproductive success for both lineages. Recent studies have shown that a grandmother’s increased longevity, however, may be related to fewer grandchildren, and that her presence might increase infant mortality.
Building on previous studies focused on mortality and birth rates, we looked specifically at how grandmothers affect postpartum mother and infant health within four-to-six weeks after the birth of a healthy term infant. To assess the health of the mother, we conducted interviews with postpartum women in the northwestern United States and had participants fill out the Edinburgh Postnatal Depression Scale (EPDS). To measure infant health, we collected mother-reported data on the frequency of visits to a health care provider and infant illness, and when possible we collected data on infant feeding patterns and growth and development history. To assess the involvement of grandmothers, we utilized interviews and questionnaires, including a modified Mother-Adult Daughter Questionnaire.
Preliminary results indicate that the grandmothers’ involvement postpartum affects both the mother’s and the infant’s overall health; however, confounding variables include the mother-daughter/daughter-in-law relationship prior to the birth of the infant, the intensity of the grandmother’s involvement postpartum, and the relationships between multiple grandmothers and other support systems. We discuss how the outcomes reported here and in the literature might translate into understanding the role of grandmothers in human evolution.