The genetic basis of hair medulla was studied by the twin method. Hair samples from 17 pairs of monozygotic (9 female and 8 male), 23 pairs of like-sex dizygotic (6 female and 17 male) and 8 pairs of unlike-sex dizygotic twins were utilized and the number of hair strands examined was 9,600. The mean intrapair differences indicate the presence of a strong genetic basis of the character concerned.
No takes yet. Share an insight, caveat, or question.
A.B. Das-Chaudhuri (1976) studied this question.