Mythbustin' Ain't Easy

The Washington Post ran an article entitled Persistence of Myths Could Alter Public Policy Approach.
It recounted some research about how people file and recall content. Here are some good quotes:

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.

The psychological insights yielded by the research, which has been confirmed in a number of peer-reviewed laboratory experiments, have broad implications for public policy. The conventional response to myths and urban legends is to counter bad information with accurate information. But the new psychological studies show that denials and clarifications, for all their intuitive appeal, can paradoxically contribute to the resiliency of popular myths.

The research is painting a broad new understanding of how the mind works. Contrary to the conventional notion that people absorb information in a deliberate manner, the studies show that the brain uses subconscious "rules of thumb" that can bias it into thinking that false information is true. Clever manipulators can take advantage of this tendency.

The experiments also highlight the difference between asking people whether they still believe a falsehood immediately after giving them the correct information, and asking them a few days later. Long-term memories matter most in public health campaigns or political ones, and they are the most susceptible to the bias of thinking that well-recalled false information is true.

The experiments do not show that denials are completely useless; if that were true, everyone would believe the myths. But the mind's bias does affect many people, especially those who want to believe the myth for their own reasons, or those who are only peripherally interested and are less likely to invest the time and effort needed to firmly grasp the facts.

The research also highlights the disturbing reality that once an idea has been implanted in people's minds, it can be difficult to dislodge. Denials inherently require repeating the bad information, which may be one reason they can paradoxically reinforce it.

Indeed, repetition seems to be a key culprit. Things that are repeated often become more accessible in memory, and one of the brain's subconscious rules of thumb is that easily recalled things are true.