To my mind, a BIG part.
Normally good-hearted people can be coaxed to become malcontents.
For example, some families create an environment which encourages griping and grudge-bearing in their children. Other families encourage more positive attitudes in the children.
Hey, I think those "families" make some of their "kids" post on FR! :-)
I've been giving the media driven panic some thought; especially now that I have seen them drive some stories, like Katrina and ...........and, well, all of them........LOL.