What is the difference between Nature and Nurture?

This is a
convenient way to discuss the two dominant influences on human psychology:  the inborn, genetic
traits (strength, height, hair color, etc.) and the acquired behavioral traits from early
experiences (caution, risk-taking, adventure).  The question is which influence is strongest?
And how can Nurture alter Nature?  Does a persons behavior reflect his/her genetic beginnings
(love of sports, loyalty to race) or does the behavior reflect lessons learned as one grows up
(fear of heights, love of adventure).  The underlying assumption of psychologists is that a
persons choices are not automatically free, but influenced by earlier decisions, experiences,
etc.  Nature may give a person a predilection for choosing one behavior over another, but
Nurture guides those predilections by providing pleasure/pain reactions that direct our next
decision.