Study on the heredity of the head size in fifty Punjabi families

Abstract

An attempt has been made to study the inheritance of the size or the Inrgeness of the head as suggested by the value of the Cephalic module or Head module. The material for the present study consists of 50 families with 76 adult offspring and 12 pairs of twins (4 MZ and 8 DZ pairs). The largeness of the head is dependent to a large extent on the individual parts of the cranium and it may be fairly assumed that the individual parts of the cranium are determined by hereditary factors, may be polygenic in nature, which are controlling their growth and development, though environment also plays its role. Presently it is not possible to ascertain the exact mode of inheritance of the head size, nevertheless, it may be stated that the size or the largeness of the head as represented by the Cephalic module is determined by polygenes in all probability with additive effects, which are too small to be traced.