Biological diversity is a hallmark of Indian populations. Anthropologists have always shown deeper interest in indigenous and /or tribal populations. In the present study it is proposed to study the morpho-physiological variations, parent-child correlations and heritability estimates among the Santhals, a tribal group from West Bengal. Santhals of this area have low socio-economic status. Although all of them are non-vegetarians, they can hardly afford it more than once in a month. Both sons and daughters exhibit great biological affinity with their parents among Santhals. Sons are taller and have higher linear body measurements than their fathers, whereas, daughters have greater body measurements than their mothers. This suggests a positive secular trend among Santhals. Significant intrafamilial resemblance is evident in body measurements and physiological functions. Both sons and daughters have similar degree of resemblance with their parents among Santhals. The finding is confirmed from the heritability estimates of different morpho-physiological characteristics. Succinctly, Santhals of Bankura have noticeable secular trend and strong biological intrafamilial affinity.