it's not clear to me that nastiness is more common at hacker forums. a certain kind is. but i've seen much nastier stuff on parenting forums (which i've been to a lot).

on parenting forums, you don't find so many jerks. when people are mean, they tend to be a bit more subtle (or passive aggressive) about it. but they make it emotional and personal, and i think that does a more effective job of actually hurting anyone.