Last Updated Oct 24, 2008 7:57 AM EDT
One of the comments I got asked the following excellent question: how do we know that repeating a negative is bad? What's does the research say? At the time, I have to say I was stumped -- I had always taken it as a given.
But I did some looking around and it turns out that there is definitive support for the theory that you shouldn't repeat a negative.
The conventional response to myths and urban legends is to counter bad information with accurate information. But new psychological studies show that denials and clarifications, for all their intuitive appeal, can paradoxically contribute to the resiliency of popular myths.The story quotes research by the University of Michigan, the Virginia Polytechnic Institute and Hebrew University, all saying basically the same thing: that people don't remember the disclaimers and the credibility of the speakers, they only retain the essence of the point. So saying "Saddam Hussein wasn't involved in 9/11" gets stuck in our heads as "Saddam Hussein 9/11."
This phenomenon may help explain why large numbers of Americans incorrectly think that Saddam Hussein was directly involved in planning the Sept 11, 2001, terrorist attacks, and that most of the Sept. 11 hijackers were Iraqi. While these beliefs likely arose because Bush administration officials have repeatedly tried to connect Iraq with Sept. 11, the experiments suggest that intelligence reports and other efforts to debunk this account may in fact help keep it alive.
Here are some more links on the subject from On the Media, the NPR show.