You know that old joke about avoiding hospitals because they have diseases there, as if you go there to get sick rather than get well? Perhaps . . .

The federal Centers for Disease Control and Prevention recently issued a flier to combat myths about the flu vaccine ... When ... social psychologist Norbert Schwarz had volunteers read the CDC flier, however, he found that ... three days later, they remembered 40 percent of the myths as factual. ... Most troubling was that people ... now felt that the source of their false beliefs was the respected CDC. ... The research, which has been confirmed in a number of peer-reviewed laboratory experiments, have broad implications for public policy. ...

The psychological studies highlight ... the potential paradox in trying to fight bad information with good information. ... 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. ... In politics and elsewhere, this means that whoever makes the first assertion about something has a large advantage over everyone who denies it later. ...

A good smear is hard to beat. But, just any old smear won't do. It has to have legs. It isn't that "whoever makes the first assertion about something has a large advantage over everyone who denies it later", it is that a good smear is difficult to refute due to its truthiness, catchiness or its ability to press titillating buttons. There's an art to myth making and artists who are adept.

I think that it's important to make this distinction, to recognize that not all assertions, accusations or myths are virulent and communicable. Better understanding of such diseases may help combat them, while flailing away at every disease, and using broad brush methods rather than smart pills, is much less effective. When you study a myth and discover its vulnerabilities you might be able to develop a truly ruthless counter-meme that turns the tables on the myth makers.