How do twin and adoption studies help us differentiate between the influences of nature and nurture?
Twins have identical DNA so their "nature" is the same.
When 1 twin is adopted and raised in a different family. ie. "nurtured" differently, they may end up having completely different characters and personalities, hobbies and interests, skills and abilities due to the different environment and influences on their development.
There is a field of study called epigenetics which tends to imply that nurture is more important than nature in development of humans.