FORDISC and the determination of ancestry from cranial measurements

Determining the ancestry of unidentified human remains is a major task for bioarchaeologists and forensic anthropologists. Here, we report an assessment of the computer program that has become the main tool for accomplishing this task. Called Fordisc, the program determines ancestry through discriminant function analysis of cranial measurements. We evaluated the utility of Fordisc with 200 specimens of known ancestry. We ran the analyses with and without the test specimen's source population included in the program's reference sample, and with and without specifying the sex of the test specimen. We also controlled for the possibility that the number of variables employed affects the program's ability to attribute ancestry. The results of the analyses suggest that Fordisc's utility in research and medico-legal contexts is limited. Fordisc will only return a correct ancestry attribution when an unidentified specimen is more or less complete, and belongs to one of the populations represented in the program's reference samples. Even then Fordisc can be expected to classify no more than 1 per cent of specimens with confidence.