Familial resemblance for head size in a Punjabi population of India

Four head measurements were taken on a sample of 45 MZ and 101 DZ twin pairs, their 125 singleton siblings, 104 fathers and 103 mothers in 146 Punjabi families living in Chandiagarh, India. The data indicate stronger genetic determination for the gross head size than its different components. Apart from genetic factors the role of environmental factors in the transmission of these traits is discussed. No higher maternal effect in the transmission of these traits have been found in the present data. However, on the contrary a higher paternal effect is indicated. The heritability estimates from siblings and twin data are higher than those from parent-offspring data. The influence of dominance factors in the transmission of head height is also suggested.