Estimating Age of Mature Adults from Degeneration of the Medial End of the Clavicle in an African American Sample

Abstract

Accurate age estimation is fundamental to identifying individuals in forensic anthropology and interpreting demographic patterns in bioarchaeology. Producing age estimates within useful ranges is particularly difficult when assessing older individuals (40+ years). Falys and Prangle (2015) developed a method (referred to henceforth as the FP method) for narrowing age-range estimates for older adults by scoring surface topography, porosity, and osteophytes of the medial end of the clavicle and applying regressions to create age-estimation ranges. That study included individuals of European decent aged 40+ years from four documented skeletal collections. New methods require testing for reproducibility as well as for the appropriateness and utility for subsamples from which the methods were not derived. Here we applied the FP method to a nineteenth-and twentieth-century African American age-and sex-documented skeletal sample (N = 229) from the Hamann-Todd Collection at the Cleveland Museum of Natural History. The method was reliable, and a statistically significant relationship was found between increased scores of degenerative features and older age. Accuracy in predicting age from the composite scores and regressions was 38.43–78.60% (compared to 96.4% from the original study). It failed to narrow age ranges beyond those available from other common aging methods (e.g., pubic symphysis, auricular surface of the ilium, sternal end of the fourth rib). Results suggest that differences in degeneration of articular surfaces are not negligible. This method should not be used universally across samples as a means of increasing accuracy of forensic identification. Sample-specific testing, in tandem with an exploration of variables that drive and/or affect age-related degeneration, should be pursued.