As for Germany, it's Like Carina said. If you get along well with your parents, you will surely be friends with them. But if something seperates you emotionally, it's not role models. This is since about 1800, by the way. Before that, we also talked to parents in formal styles. It's the time that comes right after the absolutistic kings, when the appearance of gardens was neat (we're calling the style "French" since it came from there), clothes were veeery complicated and houses had to look like a painting, inside and outside. Back then, people started to feel bad in the strict society that they were in. They wanted to have at least one place where they could be free humans, instead of representative roles, and live with love and joy instead of authority. (Plus, they were frustrated about politics.) They chose the family. This is also the time when the idea of a "private life" came up (or came back? I don't know. But it was new for the people back then). The idea that you CAN stop to play roles as long as you're at home, that is. It became an ideal, a dream, and it spread in literature and philosophy. (And I'd be sure that it's the same in other European countries in my region. Such things are often the same for wider areas because philosophy and literature communicate a lot. Also, I won't claim that we started this, of course. I don't know who started and where.) The gardens also changed :) That's another story.

In the US, I'd say it varies by the family. It's less about respecting our elders as a unit and more about how your parents raised you. A lot of children grow up and end up having their parents be their friends! We think a lot less about the generation levels or even seniority levels than Asian cultures.

Yes, in the place I'm from, a certain deference to older people is expected. Parents are not seen as friends as they often are in Western culture, but as authority figures who are supposed to instill important values and teach from experience. I still speak more freely with my friends than with my parents, because I know that there are some things they will simply find offensive, due to a generation gap. That said, as I've gotten older and since I've moved away, our relationship has changed, and although I still defer to them in many regards, I share more of my thoughts, aspirations, and true feelings with them.