Online: systemic irrationality. Systemic self-reinforcing irrationality. That's why I hang out here :P

In person, a mass lack of social skills make events unfun. Groups are much easier to get along with if they contain a reasonable mix of extroverts and introverts (read: at least two people who act like each).

I've discovered that there are a few things that can scare me away from an interesting place:

• Dysfunctional behavior. A lot of people who have sharp minds don't always apply that in the emotional realm and their behavior shows it. There's a difference between harmless instances of social skill failures and a complete failure to develop as a human being. I don't think "irrationality" covers it. I'm speaking more of a lack of moral maturity. The creepers who think the world revolves around them and the various kinds of dysfunctional behaviors that result in people hurting each other emotionally. I was recently disappointed with the amount of dysfunctional behavior I discovered in a group that I liked and have not been back for some time.

• Elitist behavior, or seeing a bunch of people commit social suicide by smearing the group as "elitist" in public. I considered quitting LessWrong because of that. I decided to stay a bit longer because there's a possibility that the pro "elitism" people will see the error of this and there are enough good things about the group that it seems worthwhile to see whether they reconsider.