The backfire effect happens when the myth ends up becoming more memorable than the fact. One of the most striking examples of this was seen in a study evaluating a “Myths and Facts” flyer about flu vaccines. Immediately after reading the flyer, participants accurately remembered the facts as facts and the myths as myths. But just 30 minutes later this had been completely turned on its head, with the myths being much more likely to be remembered as “facts”. The thinking is that merely mentioning the myths actually helps to reinforce them. And then as time passes you forget the context in which you heard the myth – in this case during a debunking – and are left with just the memory of the myth itself.
Mark Lorch writing in Business Inisder