Sex Differentials in Frailty in Medieval Ireland

Population sex differentials in morbidity and mortality are influenced by genetic, hormonal, behavioral, and environmental mechanisms, and in the majority of living human populations, females experience longer lifespans and lower mortality risks, but paradoxically, greater morbidities compared to males. This dissertation project explored sex differentials in frailty (i.e., relative risk of death compared to others in the population) in medieval Ireland to address the existing temporal and contextual limitations for interpreting how far back the modern female health-mortality paradox extends. The project had three main objectives: examine sex differentials in mortality risks between the early (500-1100 CE) and late medieval (1150-1550 CE) periods in Ireland; utilize skeletal indicators of morbidity, mortality, and developmental stress to reveal sex-based temporal and regional differences; and assess pubertal timing to better understand sex disparities in standards of living during key developmental and culturally relevant age periods in medieval Ireland. To achieve these objectives, demographic (age and sex) and stress marker (periosteal new bone formation, adult stature, vertebral neural canal diameters, and dental calculus) data was collected from Irish medieval skeletal remains. Hazards analysis was used to evaluate the effect of sex on survivorship and mortality risks; how sex differentials in survivorship and mortality risks varied over time and across geographic regions; and the effect of temporal and regional differences on sex-specific patterns of survivorship and mortality risks. Hierarchical log-linear analysis was employed to analyze the relationship between the presence of stress indicators, age, and sex; this approach allowed for an analysis of sex differences in morbidity while controlling for a possible age effect. Lastly, descriptive statistics for pubertal timing were used to provide insight into sex-disparities in living conditions. The results of the project found no discernable sex differences in frailty or morbidity and developmental stress markers, but did reveal significant regional and temporal trends for all individuals. The project also documented an elongated pubertal growth period within the sample, particularly for females, who were found to have older ages at maturation compared to males. Overall, this project improves our understanding of the effect of sociodemographic, temporal, and regional variables on health and mortality in Medieval Ireland