:-) That I like so much about you. This openness for perspectives.
Actually, we are all quite educated in manipulation. I would say that our society provides for a certain amount for it as we communicate mostly verbally instead of working the fields or do handy work for survival.
I think a Hitler or Mussolini or another dictator would never have gotten their great "successes" if there weren't many other people with the same disease (only varying in strength).
From what I think one cannot manipulate others who have integrity and a stable mental state of mind and heart.
What do you say, how good is your nose when you sniff that another one is manipulative and how relaxed is your reaction to it? Not the out- but from the inside.
... Maybe, it would be a good idea to use a scale in order to look how much it affects me when I think I am being manipulated (from 1 to 10).
I guess that my reaction to manipulations by others would strictly depend on the context and the person in front of me.
In general, most of the times, I let the other person develop their scheme in order to see their agenda and if possible revert their manipulation against them.
That being said I think that I cannot put this reaction into numerical scale, because often it is related to multi-leveled emotional and rational experience.