Impact of secular trends on sex assessment evaluated through femoral dimensions of the Czech population

Abstract

Human skeletal variability is influenced by several factors, including genetics, environment, and socio-cultural background. Forensic methods being traditionally based on targeted reference groups, it is recognized that they are population-specific. Additionally, secular trends highly impact on the skeletal morphology, but the effect of outdated methods on forensic cases is not yet well documented. This paper compares the sexual dimorphism of femoral dimensions in two samples from the Czech population separated by 60 years in time (Pachner and the Prague National Museum Collections). Significant secular trends are present within this short span in both sexes and for most of the seven tested linear variables. The consequence of secular trends on sex determination is tested with logistic regression, and a decrease in reliability is systematically observed when using the older Czech sample on the 20th century sample, whichever the set of variables included. A model based on a recent Croatian sample provides a higher reliability on contemporaneous Czech individuals. These results imply that above population specificity, temporal consistency may be a major criterion to fulfil when applying forensic anthropology identification methods.