Nature is something we are born with, its in our genes and they are passed along from our parents to us. Nurture is everything we are exposed to (our environment), and everything that we learn growing up; it has nothing to do with genes. Nurture depends on our surroundings, our environment and the way we are brought up.
I believe that both nature and nurture play a role in our reaction to a situation but nurture plays a bigger role. Nurture determines the way we react to situations because what we learn from our parents is carried with us. From our parents we learn how to deal with stress, money and relationships issues. Everyone is brought up differently so we all deal with these issues from the way that we learned from a younger age. If a young child grows up seeing their mother develop an alcoholic problem because of stress that child will most likely grow up, take what he/she learned and repeat this action when faced with stress.
Nature unlike nurture is the pretty much the same in everyone; everyone is born with human instincts and we all use those instincts in the same way. 99.9 % of every ones genes are exactly identical, and that is why so many people behave in similar ways. So nature really does not determine the way we react to situations, its nurture that takes over. Nurture is different for everyone, and they is why no one reacts to a situation in the same manner.
If raised in an angry household where every situation is dealt with in an aggressive way, a child will adopt these learnings. As the child get older he/she will deal with situations in an angry way just like they have learned. On the flip side, if a child is brought up in a home where the child's parents deal with situations in a calm and collective way, the child will learn that this is the right way to react to situations and follow in their footsteps. Early learning is the key factor in explaining why we all react differently to situations.
So you can see how nurture plays the role of how we react to situations. Nurture is essential to the way we react to situations that we are faced with everyday. Our parents and our environment shape our understanding and perspective of the world we live in.