On the page immediately before the one I highlighted above, Rube claims he was exploiting Rick's notes to tear the group apart, then, as Quillfeather said, he classifies everyone as if he got the classifications from Rick's notes. I think that's probably what you are remembering. I don't believe Rube, though. I doubt that Rick classified himself in his own notes, and he unless it was an extremely recent and short-term observation, he wouldn't have said that he was "exhausted." (He was exhausted right then because Manny and Rube weren't letting him or the others sleep.) I also doubt that Rick only made negative comments about everyone, including himself. I think Rube was just messing with them, but it could be read differently.
As Quillfeather said, that was in the "Chase" episode, specifically pages 151 and 152 in the Book 2 cbr file.
I can't blame a psychology student for taking what they learned and wondering how well it might apply to the people they know, but I would agree that they should keep most of that analysis to themselves.
Having said that, I love the way Rick impersonated Shelby in the episode after that one:
Originally Posted by Aang