First up, the Dunning Kruger thing. Here’s the wikipedia summary (it’s late, I’m back wage-slaving; forgive me).
The Dunning–Kruger effect is a cognitive bias in which unskilled people make poor decisions and reach erroneous conclusions, but their incompetence denies them the metacognitive ability to recognize their mistakes. The unskilled therefore suffer from illusory superiority, rating their ability as above average, much higher than it actually is, while the highly skilled underrate their own abilities, suffering from illusory inferiority.
Stupid people can be too stupid to understand that the evidence shows they are stupid.
And it turns out there is a social-level equivalent – extremists can be too stupid to understand that the evidence shows they are extreme (not automatically wrong, just extreme).
Those darling sociologists have a term for it, naturally – pluralistic ignorance.
Time to bust some more Ms Wikipedia on yo ass…
In social psychology, pluralistic ignorance, a term coined by Daniel Katz and Floyd H. Allport in 1931, describes “a situation where a majority of group members privately reject a norm, but assume (incorrectly) that most others accept it…It is, in Krech and Crutchfield’s (1948, pp. 388–89) words, the situation where ‘no one believes, but everyone thinks that everyone believes.'”. This, in turn, provides support for a norm that may be, in fact, disliked by most people…. Pluralistic ignorance was blamed for a perception (among American whites) that grossly exaggerated the support of other American whites for segregation in the 1960s…