Age-at-death estimation from the auricular surface of the ilium: A test of a sex-specific component method

Accurate age-at-death estimation is important for both paleodemographic studies and forensic casework. Although the auricular surface of the ilium is a well-validated skeletal indicator for aging studies, problems persist with identifying features that estimate age accurately in older individuals. This study tests the utility of one method, developed by Igarashi et al. (2005), which claims to estimate age more accurately in older individuals using a presence/absence scoring system for 13 auricular surface traits. Four hundred (400) individuals, aged 16-93 years, from the Hamann-Todd Collection were examined to test the performance of Igarashi et al.'s method in a North American sample. Pearson's product-moment correlation tests were performed for both the overall method and individual traits to assess correlation with chronological age. Eleven of the 13 traits showed statically significant correlations with chronological age, and nine were found to have higher correlations than originally reported. The method showed a tendency toward negative bias (i.e., a tendency to under-age individuals, particularly in the older age range). Models for both males and females and full and reduced models developed by Igarashi et al. were tested; the sex-pooled full model performed best, and the female full model performed most poorly. Although this method did not have significantly higher accuracy rates in a North American sample than other auricular surface methods, unique traits identified by Igarashi et al. did correlate with chronological age. In future studies, these traits should be investigated using different scoring systems (e.g., character states), as they show utility for aging research.