I think most theories by their very definition will become outdated as a new theory is taken on by the general population. This is usually the product of some academic study or other. My daughter, who has three children said the other day that there were changes in what she was advised to do with each child even though they are only a couple of years between them. My own thoughts are that there is still a lot in the pack theory that is relevant, but things usually change for the better, although the tendency is to move from one theory to another, totally dismissing the previous one. I worked for many years in zoos and wildlife parks and during that time met a chap who had a wolf pack. He used to go in and physically fight with the alpha male as he said that was the only way he would retain any standing in the pack. I neither agreed with what he did or disagreed but found it an interesting insight into our relationship with animals. I later raised two (captive bred) arctic foxes who's mother had died and kept them at home with me and my dogs. To be honest I treated them the same as the dogs and they just fitted in with the family. I never felt I had to assert myself either physically or otherwise to gain their respect but felt I did need to be a leader because without that all order breaks down. I think the pack theory is useful in understanding your dogs thinking and behaviour to a degree and that can be used to help your dogs fit in with your family/society. I love my dogs to bits but they are dogs and they come below my human family, that seems very simple to me. We will all have different views on how we view our dogs, train them and where they sit within the family but I have never yet done anything in my life that was based on one persons theory, I prefer to keep an open mind.