Nudity

Some people are nudist or exhibitionist. For others, public nudity is one of their most intense phobias. It's an extremely wide range of opinion, possibly not a bell curve. Why? Is it genetic? Environmental? If the latter, do parents have control over how the child will grow up to feel? If so, what parental actions induce each side? It's a little creepy that parents may define a such a profound psychological aspect of a child's personality. Which side leads a happier life? Intuitively, it would seem to be the side with one less phobia.