religion is a very dangerous topic for forums, especially when mentioning the G word.
ill just leave this here;
http://www.youtube.com/watch?v=K5nbav_Yj3Y
as for on topic, everything we know right now about what is "right" and "wrong" is learned.
without being taught whats right and wrong when growing up, you would have no conscious.
we define right and wrong, by how we behave in society.
im confused by your question, are you claiming that its unnatural to wear a diaper? or unnatural to pee in a toilet.
both of which can be address with the fact that byyy i think 3 years old in most children, the muscles strengthen in our urethra (i think thats right.) and the child realizes they dont need to wear diapers anymore. thats why forcing potty training on children usually works out badly or with the child resisting alot before the specific age.
boy, who knew my psychology cclass would actually teach me stuff .__.