The Washington Post ran a fascinating article today about the persistence of myths, even in the face of a solid debunking. We’re not talking about Bigfoot or UFOs here either: even perfectly mundane information seems to get easily garbled and reversed in people’s memories:
The federal Centers for Disease Control and Prevention recently issued a flier to combat myths about the flu vaccine. It recited various commonly held views and labeled them either “true” or “false.” Among those identified as false were statements such as “The side effects are worse than the flu” and “Only older people need flu vaccine.”
When University of Michigan social psychologist Norbert Schwarz had volunteers read the CDC flier, however, he found that within 30 minutes, older people misremembered 28 percent of the false statements as true. Three days later, they remembered 40 percent of the myths as factual.
Younger people did better at first, but three days later they made as many errors as older people did after 30 minutes. Most troubling was that people of all ages now felt that the source of their false beliefs was the respected CDC. (empahsis added)
That last issue is probably the most incredible of all. Not only does trying to debunk myths sometimes backfire, but if the debunking comes from a credible source, many people can actually become more certain of the falsehood!
Of course, as the article notes, a large part of this effect seems to come from what I would have expected: the main reason people get particular things wrong is because they don’t care about getting them right in the first place. Correcting error takes real time and effort, and in any population you’ll always have a decent amount of people just not interested enough in the particular subject to bother. This isn’t necessarily because they are stupid or irrational either: they just don’t value learning or retaining information about the particular subject in question. Heck, I’d like to think of myself as decently intelligent and widely informed, but if you quizzed me on a subject like the history of quilt-making 3 days after forcing me to read about it, I doubt I’d do very well either.
Still, for anyone that aims to purge myths and debunk unjustified claims, this article should be a pretty humbling read. Once bad information is out there, correcting it is an uphill battle all the way… which is just one more reason to encourage people to be more skeptical in the first place.
(Hat Tip to RMZ from the the Skeptics Guide message boards.)