A question about the nature (no pun intended) of some human behavior. The crux of the question is this: there are some human behaviors that are instinctual, and others that are learned. However, learned behavior is important to the survival of humans in an evolutionary sense, in that our brains are wired so that we have to learn stuff in order to survive; our instincts alone won't cut it. So, in a sense, learned behavior is natural. Go figure.