Sex Estimation in Forensic Anthropology: Skull Versus Postcranial Elements


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M. Kate Spradley, Ph.D.
Department of Anthropology
Texas State University
601 University Drive
San Marcos, TX 78666


Abstract:  When the pelvis is unavailable, the skull is widely considered the second best indicator of sex. The goals of this research are to provide an objective hierarchy of sexing effectiveness of cranial and postcranial elements and to test the widespread notion that the skull is superior to postcranial bones. We constructed both univariate and multivariate discriminant models using data from the Forensic Anthropology Data Bank. Discriminating effectiveness was assessed by cross-validated classification, and in the case of multivariate models, Mahalanobis D2. The results clearly indicate that most postcranial elements outperform the skull in estimating sex. It is possible to correctly sex 88–90% of individuals with joint size, up to 94% with multivariate models of the postcranial bones. The best models for the cranium do not exceed 90%. We conclude that postcranial elements are to be preferred to the cranium for estimating sex when the pelvis is unavailable.