Assessment and improvement of sex estimation standards for application in Holocene San and Khoekhoe populations

Abstract

AbstractAccurate population‐specific sex estimation standards do not exist for southern African Holocene San and Khoekhoe populations. Due to markedly small stature, skeletal gracility, and physically active lifestyle, this population exhibits reduced sexual dimorphism, complicating application of standards developed elsewhere. The effectiveness of common sex estimation approaches were assessed and optimized for San and Khoekhoe populations. One‐hundred seventy‐five adult archaeological San and Khoekhoe skeletons were studied. Sex estimates from seven morphological traits (cranial and mandibular) and six metrical parameters (mandibular, humeral, and femoral) were compared with pelvic (Phenice) sex estimates to assess agreement. Results were analyzed using chi‐squared tests, univariate statistics, and cross‐validated discriminant function analysis. The effectiveness of individual cranial and mandibular traits varied: The mastoid process and mandibular shape produced the highest agreement rates with pelvic sex estimates (73% and 72%, respectively), while mental eminence and nuchal crest produced the lowest (both 53%). The nuchal crest exhibited a strong sex bias. All mandibular and long‐bone metrical parameters were sexually dimorphic; femoral and humeral vertical head diameter (FHD and HVHD) were the most discriminatory. The discriminant function equations showing the highest agreement with pelvic sex estimates were direct multivariate bicondylar breadth, FHD and HVHD (77%), univariate FHD (75%), and stepwise multivariate FHD and HVHD (73%). All variables were sexually dimorphic, but the reduced sexual dimorphism in this population necessitates careful choice of traits. Trait scores considered diagnostic of males and females may require adjustment to improve discriminating power. This study identified the most accurate areas to target for sex estimation and generated the first discriminant functions specific to archaeological San and Khoekhoe people.