The Marine Corps has been around the longest, and they take a lot of pride in their traditions. The Marine Corps tends to attract a certain type of person. They don't offer bonuses or extra college money. They offer that you can be a Marine. For a lot of people, that is enough, and they are very proud that they have earned that. The majority of the "fights" are probably just the normal BS between the branches. Yes, there are some Marines who really think that their poo doesn't stink because they happen to be a Marine, but overall, I think they just take pride in being squared away, in shape, and well trained. Nothing wrong with that.