Parents who believe falsely that vaccination is dangerous or unnecessary for children present a real public health hazard, reports Mother Jones. That’s why researchers, in a major new study published in the journal Pediatrics, tested four different pro-vaccination messages on a group of 1,759 American parents with children under 18, holding a variety of attitudes about vaccination, to see which one was most persuasive in persuading them to vaccinate.
Three of of the messages were based very closely on how the US CentrEs for Disease Control and Prevention itself talks about vaccines. ‘The results can only be called grim,’ writes Mother Jones. ‘Not a single one of the messages was successful when it came to increasing parents’ professed intent to vaccinate their children. In several cases the more frightening messages actually backfired, either increasing the ill-founded belief that vaccines cause autism or even, in one case, apparently reducing parents’ intent to vaccinate.’
The study, by political scientist Brendan Nyhan of Dartmouth College and three colleagues, adds to a large body of research on how hard it is to correct false information and get people to accept indisputable facts. Nyhan and one of his coauthors, Jason Reifler of the University of Exeter, are the co-authors of a much-discussed previous study showing that when politically conservative test subjects read a fake newspaper article containing a quotation of George W Bush asserting that Iraq had weapons of mass destruction, followed by a factual correction stating that this was not actually true, they believed Bush’s falsehood more strongly afterwards — an outcome that Nyhan and Reifler dubbed the ‘backfire effect’.
Full Mother Jones report
When Corrections Fail, original Nyhan study on the persistence of misperceptions