Thin-skinned prejudiced pessimist

Recently David has read what is apparently a very interesting book on personality analysis. When you are talking with him he will randomly pause as you talk, stare off into space, and then nod his had and say: "Yeah, you're a J." I'm apparently something like an NJ$*2P8 or something. It means something along the lines of: "You're a person who is quick to judge people, is wholly concentrated on the negative aspects of life, and takes others opinions too seriously." or something to that extent. I think the only compliment he's given me is "decisive" which is not much of a compliment when you realize the other choice was "cautious." I would rather be decisive than cautious though.