Path analysis of total palmar pattern ridge counts.

Recently a new dermatoglyphic measure was defined called the Total Palmar Pattern Ridge Count (TPPRC), which is the sum of the ten single counts (Malhotra et al., 1981). Malhotra and associates presented estimates of five familial correlations, including twins, which are analyzed here using the models and methods of path analysis. It is concluded that about one-third of the variation in the TPPRC is accounted for by additive genetic factors (h2 = .37 +/- .06). However, the observed MZ twin correlation (.8) cannot be explained in terms of h2 alone, requiring either intrauterine environment specific to MZ twins or dominance deviations. This second source of family resemblance cannot be resolved in this material.