Question

How can twin and adoption studies help us understand the relative contribution of genes and environment?

Answer 1

Explanation:

To determine the influences of environment and heredity, the home environment needs to be controlled while heredity is varied. Identical twins, who develop from one egg that splits in two are genetically identical. Fraternal twins develop from two fertilized eggs and are genetically no more similar than brothers and sisters. Adoption studies allow us to determine if adopted children are more like their adopted families, who contribute to the home environment, or to their biological parents, who contributed their genes. Adoptees' traits bear more similarities to their biological parents than to their care giving adoptive parents. Environmental factors shared by a family's children have virtually no impact on their personalities. Studies of adoptive families have provided clues to hereditary and environmental influences. Adopted children share many values and attitudes with their adoptive parents, but adopted children's personalities tend to display the genetic legacy of their biological parents.