An unexpected patterning of neonatal mortality rates by mother’s race and age can be viewed as evidence of premature aging. National data on first births for white and Mexican American women reveal that, as expected, infant mortality rates are lower for mothers who give birth in their twenties compared to those in their teens.15 The opposite pattern is evident for black and Puerto Rican women, where the lowest rates of neonatal mortality are evident for births during the 15–19 age group, with rates increasing as childbearing is delayed to ages 20 to 29 or later. Geronimus’15 “weathering hypothesis” argues that for groups residing in unhealthy contexts, chronological age reflects higher levels of exposure to adverse conditions in social and physical environments and greater wear and tear on physiological systems.
