I'm not a psychologist, but 2 points I'd throw out there about small groups in general:
1. You're generally held to a higher standard within your circle. There's more pressure to succeed and look good, and you can't hide as easily.
2. You know how to succeed and operate better without outside help (internal or external to the group); you're probably more self-motivated and have a thicker skin than most people because you've been instilled with an underdog spirit (however truthful it really is).