Privacy and Intimacy

It is nearly impossible to ask someone why they do something that is ingrained in their culture. I would like to think of an example in American culture, but I am American. However, I have thought of a question I would like to ask a theoretical Japanese person.

"How is it that you are unembarassed of your body (hence no swimsuits in hot springs, open urinals in the middle of a public park...) but do not display any emotional affection in public?"

We see children of different gender changing clothes together, completely unconcerned. The view of the body is very comfortable here. Yet, they are a modest people, not counting a few teenagers. We know from our friendships that the people of Hayato are warm, family oriented people (okay, some work too much) ---but a hug is saved for the child and only on a special holiday will the mother exude such intimacy in public.

Perhaps the tables should be turned....How is it that Americans are so hung up on their bodies and equate bodily closeness with intimacy? Now which culture sounds more confused?