Where do you stand on the nature vs. nurture issue? How much of what you are is due to your genetics, and how much is due to your environment?

Watch this video on twins (9m:38s). Where do you stand on the nature vs. nurture issue? How much of what you are is due to your genetics, and how much is due to your environment?
If you would have been adopted by another family as an infant, would you be the same person you are now or a different person? Explain.
https://www.youtube.com/watch?v=IyT2AlzzzQs