Excellent article by Jonah Lehrer of the New Yorker.
"I know so much I don't know where to begin" http://www.newyorker.com/online/blogs/frontal-cortex/2012/06/daniel-kahn...
Which is related to "Smart people don't think others are stupid": http://sivers.org/ss
My experience is that I cant tell someone what I think the truth is and expect positive results. I can only present information that may excite them to discover the connections I think are important. A person who discovers something is more likely to become active than a person who is told they were wrong about something.
The difference between the two outcomes is directly related to the way information is presented. Is it adversarial or interesting?
Occasionally people can agree on the input to a function and the function specification, and they will regard the answer as true, but only the experience of evaluating the facts can really convince a person. Just telling them does not work.... and it shouldn't.