Do you think your moods are controlled by your brain chemistry or that your brain chemistry dictates your moods? Do you believe people are born with particular emotional temperaments or that they are primarily shaped by environmental factors?
Jeez, what a crap question this is. 'Do you think that your feet define what shoes are most comfortable for you, or is it that the shoes that are most comfortable to you depends on the shape of your feet?'
Answering the question that IS a question: I do think people tend to follow nature and nurture in roughly equal percentages: I know I'd be a very different person if I'd been brought up by different parents and exposed to different stimuli by my parents. I frankly think I'd be worse off for it.