Climate and head form in India.

The relationship between head form and climatic variation was investigated in different tribal and caste populations of India. The magnitude of the cephalic index varies significantly in different zones. In tropical zones, head form is longer (dolicocephalic), but in temperate zones, head form is more round (mesocephalic or brachycephalic), especially among Scheduled Tribes (ST) and Scheduled Castes (SC) than among other castes. These trends possibly support a climatic adaptation model in head form differences among ST and SC in India.