A Test of the (hu)MANid Program on a Diverse Sample of Mandibles

Abstract

The (hu)MANid program is a free, web-based software using mandibular metric and morphoscopic variables to estimate sex and ancestry. The database consists of 1,745 individuals from 15 populations (modern, historic, and prehistoric). The required use of a mandibulometer presents two limitations. It is an expensive piece of equipment not available in all labs, and many users do not have experience using a mandibulometer, so error can be high. To address this, three-dimensional surface scans (3D scans) provide an alternative method for data collection. Here, the authors assess the accuracy of the (hu)MANid program on a diverse sample, compare accuracy from 3D scans and physical measurements, and evaluate whether mandibulometer measurements increase classification rates. Six metric and morphoscopic variables were collected from 3D scans (Ntotal = 555) and from bone (Ntotal = 41). Three additional mandibulometer measurements were collected from bone. Mixture discriminant analysis and non-stepwise options were applied due to reported higher correct classification and no significant difference when using stepwise options. Test samples with matching reference groups from the digital measurements had higher than chance average correct classifications for ancestry and sex/ancestry combined. Pooled sexes had correct classifications higher than chance for all comparisons except females using digital measurements. Physical measurements had a higher correct classification rate than digital measurements despite the small sample size. Including mandibulometer measurements did not significantly increase classification rates for physical measurements. Results indicate that hu(MAN)id is better than chance but suggest additional testing due to a lack of diversity in the physical measurements.