Do people show more respect when communicating with strangers than with their friends?

I'd say people generally show more respect when communicating with strangers, and that's largely because there's more social pressure to maintain proper manners with people you don't know well. For example, in Shanghai where I live, you'll notice how politely people interact with shop assistants or taxi drivers compared to how they might joke around with close friends. That said, I don't think it means we respect our friends less - it's just that with close relationships, we feel comfortable being more relaxed and direct. Like with my high school teacher Mr. Wang I mentioned earlier - after we became closer, our communication became more casual, but the underlying respect was still there.