About old domain names: Do you think Google favors them?

Do you think that Google favors old domain names? In my post in my other blog, I mentioned that I have a few domain names that were registered 3-4 years ago and I have not been actively promoting them but today I found out that they are mostly having PageRank of 3 to 5!

Yes, I have promoted them in the past using links exchange and today I still see the links.

What do you think? Do you think Google favors old domain names? And do you think they also favor 'old' links?