This explains so much...

Why lies work:

Consider, for starters, this paradox of social psychology, a problem for myth busters everywhere: repeating a claim, even if only to refute it, increases its apparent truthfulness. In 2003, the psychologist Ian Skurnik and several of his colleagues asked senior citizens to sit through a computer presentation of a series of health warnings that were randomly identified as either true or false — for example, “Aspirin destroys tooth enamel” (true) or “Corn chips contain twice as much fat as potato chips” (false). A few days later, they quizzed the seniors on what they had learned.

The psychologists expected that seniors would mistakenly remember some false statements as true. What was remarkable, though, was which claims they most often got wrong — the ones they had been exposed to multiple times. In other words, the more that researchers had stressed that a given warning was false, the more likely seniors were to eventually come to believe it was true. (College students in the study did not make the same mistakes.)

To understand this turnabout, says Norbert Schwarz, a psychologist at the University of Michigan who worked with Skurnik on the study, it helps to know how our brains suss out truth from fiction. To determine the veracity of a given statement, we often look to society’s collective assessment of it. But it is difficult to measure social consensus very precisely, and our brains rely, instead, upon a sensation of familiarity with an idea. You use a rule of thumb: if something seems familiar, you must have heard it before, and if you’ve heard it before, it must be true.

The rule obviously invites many opportunities for error. The seniors in Skurnik’s study couldn’t remember the context in which they had heard the health claims (research shows that we are quick to forget “negation tags,” like whether something is said to be false or a lie), so they relied, instead, on a vague sense of familiarity, which steered them astray. Repetition, psychologists have shown, easily tricks us. Kimberlee Weaver of Virginia Tech recently found that if one person tells you that something is true many times, you are likely to conclude that the opinion is widely held, even if no one else said a thing about it.

It all starts to make sense now, everything from the War in Iraq to Rush Limbaugh.