I was reminded of a classic critique of psychoanalysis the other day. It was the one that claims that psychoanalysis isn't falsifiable because if the patient disagrees with the analyst, his protests are only taken to confirm the interpretation.
It's interesting to me to imagine how self-satisfied the person who makes this argument would be with himself. How untroubled he is by the different affective experiences in other human beings that he would never consider it odd that a person might dismiss something quickly when they had just contemplated other things with an open and hesitant mind. But, I'm sure that these same philosophers would look with contempt on a room full of social workers who are attuned to such experiences but couldn't solve a simple math problem...
Anyway, along with the idea that such a quick no, or nos that come in large quantities, someone defensively saying that they x has nothing to do with y (when x had not been implied at all), etc., might mean yes, there is similar clinical phenomenon I'd like to point out.
Often times a person might get into a description and emphasize the same word many times, or speak with a much different tone when they say a word. Sometimes, this emphasis makes the opposite salient and too much emphasis on this means thisn't.
With a thisn't, for example, a person who brings up someone who is really big, is left with the word small, and this provides the basis for associations that lead one to an interesting area.