Using CRANID to test the population affinity of known crania

CRANID is a statistical program used to infer the source population of a cranium of unknown origin by comparing its cranial dimensions with a worldwide craniometric database. It has great potential for estimating ancestry in archaeological, forensic and repatriation cases. In this paper we test the validity of CRANID in classifying crania of known geographic origin. Twenty-three crania of known geographic origin but unknown sex were selected from the osteological collections of the University of Melbourne. Only 18 crania showed good statistical match with the CRANID database. Without considering accuracy of sex allocation, 11 crania were accurately classified into major geographic regions and nine were correctly classified to geographically closest available reference populations. Four of the five crania with poor statistical match were nonetheless correctly allocated to major geographical regions, although none was accurately assigned to geographically closest reference samples. We conclude that if sex allocations are overlooked, CRANID can accurately assign 39% of specimens to geographically closest matching reference samples and 48% to major geographic regions. Better source population representation may improve goodness of fit, but known sex-differentiated samples are needed to further test the utility of CRANID.