This is kind of a touchy subject. I had an old woman who had a husband that I was meeting. I ask for his name and before he could speak his wife said, "*you* can call him Mr. Skinner". That burnt me, I never visited again. I have no respect for people who believe they have to demand it to get it. So as far as the age thing goes, age doesn't matter IMHO. I'll refer to a holy bible verse, "Do unto others, as you would have other do unto you".
Also want to add, that people who are elderly and are nice, usually have good nuggets of information and knowledge to give, and I usually give them all ears.