Geography and Anthropology, Louisiana State University
Thursday All day, Plaza Level
This study assesses sexual dimorphism of the mastoid process in samples of African-Americans (AA) and European-Americans (EA). The mastoid process is a classically used indicator of sexual dimorphism in the area of bioarchaeology and forensic anthropology. Variation in size and shape of cranial elements, including the mastoid process, has been found to differ significantly between populations. This study uses a sample of 55 AA females, 50 AA males, 49 EA females, and 49 EA males from the Hamann-Todd Collection at the Cleveland Museum of Natural History and the WM Bass Donated Collection at the University of Tennessee, Knoxville. Three measurements were taken on the mastoid process: height, width, and thickness. Results show that both AA and EA display sexual dimorphism in mastoid height and width, with males being larger. AA males have significantly thicker mastoids than AA females, but EA males and females do not differ significantly. In both groups, mastoid width is the most dimorphic trait among the three measures. AA males are not significantly different than EA males in any of the three traits, but EA females have significantly thicker mastoids than AA females, but these two groups do not differ in the other two traits. These finding highlight the importance of considering population based differences when assessing for sex.