They don't hear a single fact you throw at them

Your audience.

Our writing and speaking are usually an attempt to persuade people that something is true or that they ought to do something.

It's harder than we think. We tend to throw facts at our audience, and that's probably the least effective thing we can do.

People don't let facts get in the way of a good belief.

Brendan Nyhan, a professor of political science at Dartmouth, has been looking into this, and what he's learning has relevance for anyone writing in business. Maria Konnikova summarizes in The New Yorker:

If information doesn’t square with someone’s prior beliefs, he discards the beliefs if they’re weak and discards the information if the beliefs are strong. 

Here's a crucial distinction:

When there’s no immediate threat to our understanding of the world, we change our beliefs. It’s when that change contradicts something we’ve long held as important that problems occur.

It's easy to see this in an historical context.

Take astronomy. If someone asked you to explain the relationship between the Earth and the sun, you might say something wrong: perhaps that the sun rotates around the Earth, rising in the east and setting in the west. A friend who understands astronomy may correct you. It’s no big deal; you simply change your belief.

But imagine living in the time of Galileo, when understandings of the Earth-sun relationship were completely different, and when that view was tied closely to ideas of the nature of the world, the self, and religion. What would happen if Galileo tried to correct your belief? The process isn’t nearly as simple. The crucial difference between then and now, of course, is the importance of the misperception.

Think of the controversies today: global warming, vaccination, raw milk, on and on. You won't get very far throwing facts at these issues.

When people feel their sense of self threatened by the outside world, they are strongly motivated to correct the misperception, be it by reasoning away the inconsistency or by modifying their behavior, Konnikova writes. 

To address this one researcher proposes an exercise in self-affirmation: either write down or say aloud positive moments from your past that reaffirm your sense of self and are related to the threat in question. Research suggests that affirmation makes people far more resilient and high performing, be it on an S.A.T., an I.Q. test, or at a book-club meeting.

In this way a person's identity is less threatened by the issue.

It's also possible to approach issues in a neutral way. Why unnecessarily drag identifications into a matter? For example, the danger of smoking isn't Republican or Democratic. So why make it so?

What are the core beliefs of your audience? What are you planning to write or say that might threaten those beliefs? Is it absolutely necessary to go there? Or can you elevate your words to a larger identity that encompasses everyone?