My brother Steven has for a while referred to my brother Carson as simply "Brother", both in direct address ("Hey, Brother") and in reference ("I heard from Brother that you..."). Today, he clarified to me that he also refers to Tyler as "Big Brother", Andrew as "Bigger Brother, and me as "Biggest Brother". Note that this directly corresponds with birth order, not relative size.
I got a huge kick out of this, because this directly parallels my own form of referring to things using descriptive nominatives rather than their actual names. When Becki and I got married, she had two cats. Because I wasn't 100% clear which one was named what and didn't want to stop and think about it all the time, I took to addressing them as simply "Black Cat" and "Grey Cat". A few years later, Grey Cat died and Black Cat just became "Cat". A little while later, Becki took the first cat she had back from her mom. That cat stays in our basement and is "Downstairs Cat". The cat upstairs doesn't have to be "Upstairs Cat", though. She is still able to retain the title of just "Cat".
This is the case for inanimate objects as well. While I do talk to inanimate objects, I would never name them. That's just silly. Instead, I will address them only as "Car", "Computer", "TiVo", etc.
Now that Joey talks so much, I address him as "Joey", but it wasn't always that way. He was "Baby" nearly up until the time Miranda was born. Miranda got to be "New Baby" for a while, then eventually settled in to the now available again "Baby". She's almost a year and a half old, and I still probably call her "Baby" about ten times as often as using her actual name.
I'm trying to think how this got started. How did my brain fall into this pattern of description rather than naming? I've come up with three possible influences that have shaped my way of thinking about names and forms of address. First: there's my horrible memory for names. If everyone in the world would allow themselves to be called by descriptive listings of their attributes, everything would be a lot easier. Instead of seeing a guy in the grocery store and trying to remember "Is that Mr. Palowechez?", you could just confidently stride up to him and say "Hey, Thick Across The Middle Bald Guy! How's your wife, Shaves Her Moustache?"
Two: On the late lamented Viva Variety, there was a segment called "Monkey Sports", where the sidekick, Johnny Blue Jeans, would demonstrate sports with a monkey. The genius of this bit didn't entirely lie in the aptness of its title, however. Near the end of one segment, Johnny Blue Jeans was giving praise to the monkey, who had just done a great vault or something, by saying, "That's a ten for you, monkey".
That line has stuck with me for years, because it just made so much sense that if you had a monkey, you would address it as "Monkey". There's no point in giving it silly names except to impress your friends who otherwise wouldn't be impressed enough that you had a monkey. When you actually wanted to communicate with the monkey, you call it "Monkey". That was one of those points where something just all of a sudden clicks and universal truth shines through the heavens and becomes clear.
Third (and here's where I bring it all back to Steven in my very own warped chiasmus): Many years ago when Steven was little, I was charged with taking the cat now known as "Downstairs Cat" on a plane from Tucson to Salt Lake. Steven was petting the cat in its carrier and said "I think this cat's name should be 'Soft'". Minutes later, the cat scratched him completely without cause (as she was wont to do). Steven said "I think today's the day we change this cat's name to 'Mean'".