An evaluation of the Acsádi and Nemeskéri Complex Method of adult age estimation in the skeletal remains of black South African individuals.

Abstract

Multifactorial approaches to skeletal age estimation are favoured over single-trait methods because they account for intra- and inter-individual differences. The Acsádi & Nemeskéri Complex Method is a multifactorial method that utilises any combination of four skeletal elements (cranium, proximal humerus, pubic symphysis, and proximal femur) and a weighting system to assess adult age. Acsádi & Nemeskéri (1970) reported an error margin of ±2.5 years when using all four skeletal elements; however, the method has been criticised for its small sample size, the statistical validity of the averaging procedure, and the consistent under- and overestimation of age for older and younger individuals, respectively. Its effectiveness in populations outside Europe remains uncertain. Therefore, this study tested the Complex Method’s performance on a black South African sample (n = 103) with individuals of known age at death. Blind analysis of the phase descriptions for each skeletal indicator was used to estimate age. The Complex Method demonstrated weak-to-moderate correlations with age, substantial inaccuracy (4.3 to 24.7 years for females and from 2.8 to 26.4 years for males), and systematic age-related bias, with only a limited proportion of individuals correctly classified within narrow age intervals (10.7%). These findings indicate that, in its current form, the method has restricted forensic applicability in this population, particularly at age extremes. This study highlights the importance of population-specific validation and recalibration and emphasises that historical multifactorial approaches may not generalise across populations without methodological refinement.