Groucho Marx once said he wouldn't want to be a member of any club that would accept him. I feel similarly about groups, though i've been part of some very cool gruops. Most notably, Many Hands, the art co-op where i was a member for many years.
Group dynamics are interesting, but i dropped a class with that title soon after the professor said we'd be videotaped.
Groups make me uncomfortable -- i prefer one on one interactions.
Then there's always that mob mentality that is cause for concern.
i've been going to an assertiveness training group for years now. i know how to be assertive though i don't always feel i have the right to be assertive.