A Question on how Cultural borders work

[Dr,ape]

This seems strange compared to Civ3.

My cultural border from one of my core cities extends far into my neighbor's front lawn (2 squares away from their closest city, 5 from mine). I build a new city 1 square away from the border, meaning 3 squares from theirs. My border SHRUNK as a result and now this new city is right on the border, while my neighbor got new territories.

Is this to be expected or not?

[Simplicity]

That's odd... I assumed that the cultural borders were determined by the *sum* of the culture put into them by the surrounding cities. If the border shrank, then it clearly can't be that simple, since adding a city would never decrease that sum...

[khumak]

I think your borders are more highly influenced by the culture of the nearest city than by your overall culture so if your overall culture is huge and you build a new city on the border that might cause your border to shrink until the new city built up enough culture to expand a couple of times.

[krytonix]

Wow, that sounds strange. Is it possible the opponents border expanded right around the same time as you plunked that city down? Or did it happen immediately?