Well, different cultures in the setting have different standards of what is acceptable behavior and atttitudes - in some places it is closer to "modern"* and others have a more "medieval" feel to them.
I guess I never overtly tell the players, "this is what society is like" but I hope they glean it from the info I give them and I answer any detail they want to know about the culture in the geekish minutae that only a DM can have.
In some places in Aquerra, for example, female characters will be ignored or worse simply b/c they are women (true is the same for people of different races), being a PC does not exempt you from that - though the average person might be wary about what he says or does around a woman carrying around a great sword
In some place it is totally acceptable to dump your chamber pot in the street - that is just what people did in the time and with the technology the average fantasy setting emulates.
There is no "talking back" to people in authority either. I mean, you can have your character do it - but there are going to be consequences - people tend to smart mouth authority these days and talk snap about their leaders to their faces or to their followers' faces - that doesn't fly in most psuedo-medieval cultures. I would try to prevail upon a player that a character raised in such a society would have deeply ingrained taboos about such behavior.
But then again, there is always room for exceptions in any society. . .
Some things remain constant in the setting though - which are probably influenced by a modern sensibility. For example, slavery is evil and abhorant - does that mean that some good and neutral people don't have slaves? No, it doesn't - it just means that freeing a slave is always "good" (though not always "lawful") regardless of the circumstances.
All of that to say. . .I had a hard time deciding which poll choice to pick so I took the last one. . .
* (though modern has a lot of ground to cover b/c there are people living all over the world with different ideas of what is acceptable - in some places men and women don't dance together, or in another straight male friends hold hands, etc. . )