How do you respond to "thank you"?

Have you ever paid attention to what people say in response to “thank you”?

I sat with a friend the other night discussing the apparent difference, and in having both noticed it, we agreed that it seems older generations tend to say “you’re welcome”, whereas the younger go with “no problem” or “anytime”.

Myself, I’m an “anytime” kind of person, and in contemplating with the friend (a proponent of “you’re welcome”) it became apparent that the the two different habits seem to represent two different values and interpretations of interaction.

People who respond with “you’re welcome” are (theoretically) viewing what they have done to merit value as something of worth, value, and effort--something that deserves a thank you. As some might argue, in saying “you’re welcome”, people are attempting to convey that while their action was something of value and effort, they believe the person on the receiving end worthy of that effort.

“Anytime” and “no problem” speakers, on the other hand, view their acts as not necessarily needing thanks--their respect and value of the recipient makes the effort involved but a trifle, and thanks are not particularly necessary because they hadn’t considered not taking the action.

It’s a really interesting, if minute, difference, but when each side doesn’t consider where the other is coming from, it can come of as rude--I know I’ve had instances wherein older relatives perceived my lack of use of “you’re welcome” as disrespectful, and there have been people whose use of the same term has seemed pretentious and self-important.

Of course this isn’t a standard or a rule, but I think the fact the such a pattern is so definitely split between generations is worthy of attention. How did the same value, that of displaying the respect and value of another person, begin to be portrayed in two such different ways?