Evaluation of the (hu)MANid program for sex and ancestry estimation in a diverse, contemporary CT scan‐based sample

Abstract

Human remains from forensic and bioarcheological contexts are often fragmentary, requiring methods for estimating a forensic profile that are based upon limited skeletal features. In 2017, Berg and Keryhercz created an online application, (hu)MANid, that provides sex and ancestry estimation from mandibular morphoscopic traits and linear measurements. In this study, we examine the utility of the (hu)MANid application in a diverse, urban US adult sample (aged 20–45; n = 143) derived from computed tomography (CT) scans. We secondarily conduct a preliminary analysis of the program's utility in a sample of adolescents (aged 15–17; n = 40). Six morphoscopic, and eleven morphometric traits were recorded as directed by the literature associated with the (hu)MANid program. Percent correct classification and posterior predictive values were calculated for the sex and ancestry estimations output by the program; chi‐squared tests were employed to compare self‐reported and predicted ancestry. In the adult sample, sex was accurately predicted for 75.52% of the sample. Ancestry prediction, however, was less favorable ranging from 19.3% to 50% correct. For the adolescent sample, correct sex estimation (45%) did not surpass what could occur by chance alone, though ancestry prediction fared better than in the larger adult sample (percent correct prediction overall average: 47.5%, range 35.71%–71.43%). The (hu)MANid application shows utility for use with CT scan‐derived adult samples for sex estimation, but caution is warranted for ancestry estimation and use with samples that may not have reached full adult maturity.

A test of the (hu)MANid analytical program using a native American population

“…To determine overall accuracy, these were compared to the estimated sex and Native American ancestry. We believe this analytical approach reflects how most practitioners in the field would apply the program and is consistent with the analysis conducted by earlier tests of (hu)MANid (Farhi et al, 2023; Lynch & Cabo‐Perez, 2022).…”

“…It is important to note that the data from this study comes from dry mandibles, and not CT or 3D scans. To date, research evaluating the utility of the (hu)MANid program has primarily relied on either CT and 3D scans (Farhi et al, 2023; Lynch & Cabo‐Perez, 2022), with Lynch and Cabo‐Perez (2022) including a subset of 41 dry mandibles along with a larger collection of 3D scans. These studies have found the program to have an accuracy lower than that reported by Berg and Kenyhercz (2017).…”

“…It is important to note that the data from this study comes from dry mandibles, and not CT or 3D scans. To date, research evaluating the utility of the (hu)MANid program has primarily relied on either CT and 3D scans (Farhi et al, 2023;Lynch & Cabo-Perez, 2022), with…”

Shape variation and sexual dimorphism of the adult human mandible evaluated by geometric morphometrics

“…Kranioti et al [44] report an accuracy of 80% based on 2 linear variables in a Greek population. Other reports vary, from around 75% to almost 90%, using univariate or multivariate models [50, 51, 52, 53, 54, 55, 56, 57]. Franklin et al [58] report an exceptionally high accuracy of 95%, but this needs to be interpreted with caution, as 10 variables were applied on a sample of 40 mandibles, suggesting a danger of overfitting.…”