I think Larian said at one point that NPC will not respond to your background. They already react to your race, class and some other things and it would be too much work to implement that too.
They said if you are a noble NPC could ask what title you have or if you are a folk here what did you do to become a hero. This would open a huge bag of background related stuff, so it's better to leave it to the players imagination.
So yes, background gives only extra skills, nothing else.
Prof. Dr. Dr. Mad S. Tist
World leading expert of artificial stupidity.
Because there are too many people who work on artificial intelligence already
