Which is more important, Nature or Nurture?

The Nature vs Nurture argument has existed for as long as humans have been able to consider complex thought. The debate as to whether the nature (the intrinsic nature, the attitude, or the predisposition), or the nurture (the care, the teachings, or the conditioning) of a child is more responsible for who or what they become in adult life. 

Largely it is considered that humans are a product of context (Nurture). The situations in which we are raised have a considerable bearing on who we become in later life. But, it's not necessarily so black and white. There are countless examples of children having been born into extremely difficult circumstances, who have grown to be well rounded, high contributing members of society. 

As a result, It would be reasonable to assume that Nature is a strong factor, regardless of the Nurture (the environment) in which a person is raised. After all, there's no guarantee that someone growing up in an abusive household will then abuse others themselves. So then is Nature more important? 

The difficulty with the debate is that no one individual is the same as another. Experiments to establish the efficacy of Nature vs Nurture are difficult to perform. Not only from a human rights perspective, but additionally from a variable standpoint as well. Really there are far too many variables to control with regards to human nature, that any imposition of control on the Nurture element would be imbalanced. 

When considering this question, it's important to recognise that developmental psychology is still in its early stages, and to understand that both Nature AND Nurture are necessary factors in human development.