Haha, the positive correlation is definitely there! I live in the suburbs, and the Tube is such a pain. Since we graduated, all my friends are scattered all over, and we always have to meet in central. D: And I'm the same! Though it doesn't matter so much group size, just who's in the group. It can be a huge group all of my friends and that's okay, but as soon as there are strangers or simple acquaintances, I start worrying about small talk. Which is hard!