themselves, usually fishing for a compliment.

"Oh, I'm so ugly"
-No you're not!

etc

I'll never forget this story. I had a buddy who I was hanging out with at lunch amongst a big group of friends. One girl went on to say something like "Oh, I got a poor test score, I am so stupid, no one would ever date someone as stupid as me." The guy agreed with her and said "Yeah, you're probably right." Tons of gasps and disgusted looks went his way and the girl was visibly upset. He then stood up and said something along the lines of, "If its so heinous and disgusting for me to agree with her, its should be moreso that she suggested it in the first place. Don't talk bad about yourself looking for others to bolster yourself up. If its bad if I say it, it should be bad if you do to." He grabbed his stuff and just walked off. Took a bit but the conservations went back to normal after a few minutes, but that was a real stinger.