I think when it comes to many psychological traits, there is a fair amount of influence we can have. As a species, we are likely the most affected by the nurture component and even negative aspects could become positive if handled in the right way. I would assume that there are many psychopaths who have trained their actions (unknowingly) to positive pursuits.

What most people fail to admit though that under the right circumstances, we can all behave like the most heinous of monsters. Thankfully, most never are in those circumstances though.