Sex determination in the subadult ilia: an indirect test of Weaver's nonmetric sexing method.

The sexing of subadult remains has been an ongoing problem in physical anthropology for many years. This is due in part to the scarcity of subadult collections of known age and sex which are large enough to be used to develop and test analytical methods. Several methods have been devised but few have produced reliable results. In 1980, Weaver presented a method for sexing subadult ilia using a nonmetric trait (the raised versus nonraised auricular surface), which has an accuracy of 75% in fetal females and 92% in fetal males. His method has not been tested for reliability on a different subadult sample. An indirect test of Weaver's method was made on a sample of subadult South Dakota Arikara Indian ilia by comparing the ratio of raised to nonraised auricular surfaces with an expected 1:1 sex distribution. Bimodal sex distributions in the Arikara formed unrealistic sex ratios, following an age-related shift from a 6:1 raised/nonraised ratio in newborns to a 1:4 ratio in young adolescence. Significant age correlations were found both in the present study and in Weaver's published results. The age-to-sex correlations indicated no confounding in the present study. The results of this test suggest that auricular surface morphology is not sex specific in subadult ilia, but may be related to aspects of shape and morphology in pelvic growth.