Belief perseverance, holding onto your beliefs in the face of contradictory evidence, can be incredibly powerful. Here are a couple examples for your students.
Two people bring their new puppy, indeed the first dog they have ever owned, to the vet. When the vet tech comments on how cute he is, they are taken aback because they thought ‘he’ was a ‘she.’ The vet tech confirms that, no, indeed he is male. The vet tech points out the puppy’s penis and testicles. No, they insist, the dog is female. “I want to talk to a vet!” one of them says. The vet, unsurprisingly, says the same thing; the dog is male. The dog owners continue to argue with the vet that the dog is female. (Full story.)
At a movie theater, a couple customers are in front of the concessions counter talking about the popcorn. One of them insists that the popcorn is purchased by the theater already popped and delivered in big garbage bags. The concessions employee overhears them and makes a big show of putting unpopped kernels into the popper right behind the counter and turning it on. When the customers see this, one of them comments on how it’s just for show, that they only sell the stale, garbage-bag popcorn. The employee writes, “I guess some people just HAVE to believe that they’re getting ripped off, even when they aren’t.” (Full story.)
Your students who work with customers may have stories of their own to share.