On the assumption of equality of variance-covariance matrices in the sex and racial diagnosis of human skulls.

Many papers have been devoted to the assumption of equality of variance-covariance matrices (sigma g) with respect to the use of discriminant analysis. Most of them concentrate on the "effect" of inequality on the results, in particular on discriminant functions. In the present paper, the assumption of equality of covariances itself was investigated for measures on human skulls. Data for both sexes were compared, as well as data on several racial groups. A likelihood ratio test was used. It was concluded that the equality of sigma g between the sexes and among subraces was not questioned, whereas the results warrant some caution as to the equality of sigma g among the main racial groups.