People see things which confirm their beliefs and not see things which conflict with their beliefs. It's called Confirmation Bias. When they actually realize that they're wrong, they double down and insist that their proven wrong beliefs are true. That's called the Backfire Effect.

FEAR!

Truth is the enemy to many!

The truth is sometimes ugly and harsh...we like comfortable bubbles

Part of it is brainwashing where it is told over and over by so many that you no longer question what is being said.

We can skin this cat in so many different ways. It's not cut and dry...far from it. Even when the truth is irrefutable as 1+1=2 then someone can argue synergy says 1+1> 2 .... It depends on context, circumstances, etc

True enough in its diagnosis. I wish we could find a better way forward. Descreditng them only seems to make them dig in deeper. Ultimately, I don't now. At least with climate change we will have hind sight soon enough. But they will likely still be in denial... because that would require that they alter their world view.

Pride and hatred. Not able to humbly surrender to a learning curve. Such as Trumpets, they ignore and claim real certified news to be fake, They will not surrender their pride and feeling we were right.
It is sooooooo frustrating isn't it? Drives me nuts with two of my brothers who believe Alex Jones

"The Long Read" is the section of the Guardian this article is in. HE wouldn't get past the 1st poaragraph as HE gets all of his info from BreitFart & Pox Spews.