Lock Door Control: Cultural Cues?

My dad told me he's always confused by the door lock controls in cars.
Does the raised dot mean lock? Does the indented dot mean unlock? Or is it the other way around?
Looking at our two cars, it seems that the Japanese have a different logic from the Germans. I wonder what the thinking is behind each.
It makes more sense to me to press the indented dot to lock the doors, and the raised dot to unlock the doors.
What do you think?