I think this is an interesting article -- and I'm sure there are more than five social fallacies around. Can anyone think of any others?
http://www.plausiblydeniable.com/opinion/gsf.html
I see these acted out quite often here in the senior apartments where I live. There are a few people here no one likes, for good reason, and yet no one has the courage to not include them now and then. Leads to some interesting interactions.