On Monday, I reported on the latest study to take a bite out of the idea of human rationality. In a paper just published in Pediatrics, Brendan Nyhan of Dartmouth and his colleagues showed that presenting people with information confirming the safety of vaccines triggered a "backfire effect," in which people who already distrusted vaccines actually became less likely to say they would vaccinate their kids.
Unfortunately, this is hardly the only example of such a frustrating response being documented by researchers. Nyhan and his coauthor Jason Reifler of the University of Exeter have captured several others, as have other researchers. Here are some examples:
1. Tax cuts increase revenue? In a 2010 study, Nyhan and Reifler asked people to read a fake newspaper article containing a real quotation of George W. Bush, in which the former president asserted that his tax cuts "helped increase revenues to the Treasury." In some versions of the article, this false claim was then debunked by economic evidence: A correction appended to the end of the article stated that in fact, the Bush tax cuts "were followed by an unprecedented three-year decline in nominal tax revenues, from $2 trillion in 2000 to $1.8 trillion in 2003." The study found that conservatives who read the correction were twice as likely to believe Bush's claim was true as were conservatives who did not read the correction.