Dermatoglyphic Sexual Dimorphism in Israelis: Principal Components and Discriminant Analyses Applied to Quantitative Traits

The dermatoglyphics of 372 males and 208 females, all Israeli Jews, were analyzed comparatively. A total of 66 variables were used entailing 24 quantitative dermatoglyphic traits, 11 indices of intraindividual diversity, 15 indices of bilateral directional asymmetry and 16 indices of fluctuating asymmetry. The correlation matrices of the traits were used in a principal components analysis and the following 5 factors, which emphasize five distinct groups of variables, were identified in both sexes: 1. A “digital pattern size factor” which has high loadings for the ridge counts of individual fingers, for variables derived from these counts, and for the pattern intensity index. 2. A “palmar lines factor” which describes the variability of the main line index and of its components. 3. A “a-b ridge counts factor” which describes the variability of the a-b ridge counts. 4. A “finger ridge counts diversity factor” which has high loadings for the indices representing the intraindividual diversity of finger ridge counts, 5. A “fluctuating asymmetry factor” which concentrates the high loadings for the fluctuating asymmetry indices. The last two factors are described in the literature for the first time.There are important similarities between the two sexes in the variables associated with the factors; there are also some differences especially concerning the asymmetry indices. The discriminant analysis revealed 10 variables as the most efficient discriminants: three finger ridge counts, the right a-b ridge count, the right A-line exit, four indices of directional and one index of fluctuating asymmetry. They permit a correct classification by sex in 71.6% of the subjects. It is worth noting the discriminant possibilities of the directional asymmetry indices and the fact that the right hand possesses more highly discriminant traits than the left hand. A relation is presumed between the hemizygosity of males for the genes located on the X chromosome and higher dermatoglyphic asymmetry in males