I was usually warned by either parent that I would be spanked if I did not obey, and I think there is nothing damaging about spanking as long as a clear warning has been given -- obey or be spanked -- and the "swats" are well-controlled and easily bearable. The fact that you were not spanked after age nine would cause me to guess your father was loving and not abusive, and there is where I believe both of my parents ultimately fell quite short and did damage by spanking too much, too hard and often in anger. At some point their actions had switched from "This is going to hurt me more than it hurts you" (something I never believed since they never cried, at least not at the time) to "This is going to hurt until you have paid some kind of pride- (you are making us look bad) or ego-driven (we have all authority and power, dammit) debt to me."