And they base their rock solid belief that they are right on... What because they just feel they are right?  If there's one thing I've learned about people, it's that we're only as good as our most gullible ones.  Gullible people tend to cling to whatever appeals to them, while others often pretend to hold those same beliefs because they see an advantage to exploiting them.    I think we have a real problem in reliably distinguishing between the truly gullible and the ones who are just faking it.  It would be easy to just write them all off as idiots, but I think it would be foolish to do so.  Perhaps a better strategy would be to treat them all as fakers even though the majority of them are most likely fools.