A group of primitives stumble onto the grounds of a deserted mansion. As they explore they start to pick up the manners and habits of modern civilized people, and by the middle of the movie have turned into the hyper-sophisticated elite. However they haven't managed to turn into "nice" people and act toward each other with savage, albeit urbane, hostility and violence. Then the shine begins to wear off. They gradually become less and less civilized until by the end the survivors have turned back into the dirty bedraggled creatures they were at the beginning.

Savages (http://www.imdb.com/title/tt0069226/)

Thanks again.

You're welcome.