Hello, at the moment they need some tweaking to get the proper and desired effect and they aren't exactly clear so for that I do apologise. I'll be working on it in the next little bit while I iron out other aspects of the UI
Currently they start in the middle at exactly 50%, signifying that your character is neither one nor the other. For the sake of the variables, technically you are raising or lowering a singular personality trait, but you can read it as the emotion that the meter is tipped towards being the one your character most exhibits. For example naive/worldly: if you're under 50% you will be considered more naive, however, if you're over 50% you will be considered worldly. There aren't currently any scenes for exactly 50% so either way the game will read one way or another depending on the scene--though this is subject to change once more pressing matters are tended to.
I hope this makes sense -- if you have any further questions, please don't hesitate to ask :)