What influence does heredity have on physical growth?

Physical growth, like other aspects of development, results from a complex interplay between genetic and environmental factors. Heredity, nutrition, and emotional well-being all affect early physical growth. We know that heredity is important in physical growth because identical twins are much more alike in body size than fraternal twins. When diet and health are adequate, height and rate of physical growth are largely influenced by heredity. In fact, as long as negative environmental influences such as poor nutrition and illness are not severe, children and adolescents typically show catch-up growth—a return to a genetically influenced growth path once conditions improve. Genetic makeup also affects body weight: The weights of adopted children correlate more strongly with those of their biological than of their adoptive parents.