Twin Studies

The twin studies can help prove the concept of nature nurture. In certain studies, twins who grew up in different homes showed similarities in life choices. This proves that genes can influence personality.

If one twin is more nurtured by the parents than the other twin, then the more nurtured twin could grow up with more confidence than the one that didn't get as much nurturing; even though they both have the same genes, their personalities can differ because of the nurturing of the parents.

If parents are more nurturing to one child than another, they can the one while hurting the other. The first child could be more outgoing and social, the second child could be more shy and quiet; all because of how the parent nurtures the child.

Using twin and adoption studies, behavior geneticists can estimate the heritability of a trait.