Sex Estimation in Forensic Anthropology: Skull Versus Postcranial Elements

TLDR

The skull is commonly regarded as the second best sex indicator when the pelvis is missing. The study aims to rank the sexing accuracy of cranial versus postcranial elements and test whether the skull is indeed superior. Discriminant models—both univariate and multivariate using the Forensic Anthropology Data Bank—were built and evaluated via cross‑validated classification and Mahalanobis D(2). Postcranial elements outperform the skull, achieving up to 94 % accuracy with multivariate models, whereas cranial models peak below 90 %, leading to the conclusion that postcranial bones should be preferred when the pelvis is missing.

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 D(2). 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.