Variation and inheritance of relative length of index finger in man.

The length of index finger relative to fourth finger has been measured on parents and children in 190 families belonging to an endogamous Reddy community of Nalgonda District, India. The distribution of relative index finger length among various family groups was unimodal and symmetric. Heritability estimates based on parent-offspring regressions indicate a moderate level (40--70 percent) of additive genetic variance. There was no evidence for the influence of sex-linked additive genes.