A reevaluation of the sex prediction accuracy of the minimum supero-inferior femoral neck diameter for modern individuals

The results of an independent test of the minimum supero-inferior femoral neck diameter as a sex predictor are presented. Seidemann et al. (1) generated discriminant functions for Caucasians, African-Americans, and a combined race sample from the Hamann-Todd skeletal collection. Jackknifed classification matrices and the use of independent, random validation samples indicated a sex prediction accuracy in the 90% range. This, combined with a high rate of preservation, makes the femoral neck a significant measure for forensic applications. However, the method has not been evaluated on a truly modern sample. Data were collected for 94 males and 49 females from the Documented Collection at the University of New Mexico. The sample consists of 94 Caucasians, 33 African Americans, three modern Native Americans, two Hispanics, and 11 individuals of unknown ancestry. All individuals were born after the turn of the century. We evaluate the accuracy of the discriminant functions generated from the Hamann-Todd control sample. For Caucasians, 83% were correctly classified, for African Americans 97% were correctly classified and for the combined race function 85% were correctly classified. This decrease in accuracy is the result of the increase in African American male and all female sample means. This effectively decreases the separation between males and females for the femoral neck diameter. We generate new discriminant functions from the modern data and jackknife the classification matrices. The Caucasian function was 84% accurate, the African-American function was 82% accurate and the combined sample function was 85% accurate. The femoral neck may provide a useful alternative to multivariate techniques for individuals who are poorly preserved.