Abstract
In a study of 256 families, among whom were twins, midparent-adult son correlations for height, weight, and combined skinfold measurements were 0.67, 0.47, and 0.23 respectively. The corresponding midparent-adult daughter correlations were 0.63, 0.42, and 0.24. Midparent-growing offspring correlations were highest for height, less for weight, and insignificant for combined skinfold measurements. These data and the resemblances found between twins and siblings led us to conclude that there is a significant genetic contribution to the variation of height and weight, but that body fatness appears largely to be determined by environmental factors.