What is the nature of curses?

In Pathfinder: Kingmaker, there’s a series of quests named "Research into the nature of curses". In each quest, you investigate some curse in some area.

What is the overarching meaning of this quest series? I don’t think the game outright tells you what’s the result of your research but maybe the player is supposed to figure it out themselves?

What is the nature of curses in Pathfinder: Kingmaker?