Coming mostly from a "Younger Brother" background, my form of self-righteousness is slightly more subtle than the obvious kind that Pharisees and "Older Brothers" have. Blogger Tullian Tchividjian offers an excellent message on his blog.
Here's an excerpt:
“That’s right, I know I don’t have it all together and you think you do; I know I’m not good and you think you are. That makes me better than you.” See the irony?