Why is it so hard to change someone's mind with facts?

The obstacle is not ignorance but motivated reasoning. People do not evaluate evidence neutrally; they apply far more scrutiny to information that threatens a valued belief and accept confirming information with little examination. This is asymmetric skepticism, and it means additional facts frequently produce better-defended positions rather than changed ones, particularly among the most knowledgeable people, who have the most material for constructing counterarguments. When a belief is bound to group identity, changing it carries a social cost, since being wrong is cheaper than being disloyal to the people you rely on.

What has better evidence behind it is unglamorous. Asking someone to explain in detail how a policy would actually work often reduces confidence, because people overestimate their understanding of complex systems and discover the gap when forced to articulate it, an effect called the illusion of explanatory depth. Motivational interviewing techniques, which involve genuine curiosity and reflecting the person's position accurately back to them, outperform argument in clinical settings and increasingly in political ones. Affirming a person's self-worth before presenting challenging information reduces defensiveness in experiments. And the older belief that correcting misinformation backfires and strengthens it has itself been substantially revised, since replication work finds backfire effects rare, so correction is generally worth doing, just not by volume of facts alone.