I think DNA is a stronger factor than nature, but nature can definitely shape a person and make them tough to get a long with. You can't really say it's one or the other, because it's a combination of both. Everything plays a part in our development. However, our DNA is an amazing thing. They've done studies on identical twins who've grown up far away from each other and had very different upbringing. The result was the same in almost every case. They had the same temperament, often had similar jobs, similar education and their interests were almost always the same. Not only that, but they had similar spouses as well.