Evaluating the Accuracy and Precision of Cranial Morphological Traits for Sex Determination

Sex determination is a key analysis that forensic anthropologists perform in order to construct a biological profile of human remains. The techniques used in forensic investigations must meet the Mohan or Daubert criteria, for admissibility in a court of law. In this study, the precision and accuracy of 21 morphological characteristics of the skull were tested on a modern sample of 50 adult crania of European White ancestry. The following craniofacial features are identified as high‐quality traits, defined by intraobserver error ≤10% and accuracy ≥80%: mastoid size, supraorbital ridge size, general size and architecture, rugosity of the zygomatic extension, size and shape of the nasal aperture, and gonial angle. Ninety‐six percent accuracy and 92% precision were achieved using 20 traits in combination. Fisher's exact probability tests revealed no significant differences ( p =0.05) in the levels of precision or accuracy between age categories. Sex‐related bias in accuracy was found for the following cranial features: ramus symphysis ( p =0.009), zygomatic extension ( p =0.0016), and occipital markings ( p =0.0013). These traits demonstrated a greater tendency to be scored male than female.