Fact: Myth/ fact health campaigns tend to reinforce the myths

In a June 4 press release emphasizing the dangers of suntanning, the Canadian Cancer Society says it “is optimistic that behaviours and perceptions about tanning are changing.” Unfortunately, however, any changes for the better are likely taking place in spite of, rather than because of, the society’s efforts.

Intended to promote the society’s important message that “no tan is a safe tan,” the press release presents, in bold text, six myths about tanning — myths like “there is no conclusive evidence that tanning causes cancer” — and counters them with factual information.

The press release therefore follows the format of many public information campaigns, in which myths and facts are juxtaposed. This format has been — and continues to be — used for a great variety of such campaigns, including ones designed to educate people about cancer, influenza, vaccinations, adolescent violence and epilepsy.

Hence, the campaigns are intended to counter misinformation with accurate information, to provide people with solid evidence about various medical conditions and concerns and thereby change both their beliefs and behaviours. And in that sense, the use of the myth/ fact format is a little ironic, since there has never been any evidence that such a format changes people’s attitudes, much less their actions, for the better.

In fact, until recently there was no evidence at all about the impact of such campaigns. That has changed in the last few years thanks to recent research on the subject, but that research suggests that such an approach might reinforce the very myths it seeks to debunk.

For example, in a 2007 paper, researchers led by the University of Toronto’s Ian Skurnik assessed the impact of a U. S. Centers for Disease Control and Prevention flyer on “Facts and Myths” about the flu vaccine. Skurnik and his colleagues divided study subjects into two groups, one of which read the CDC’s flyer, while the other read a similar flyer but with the myths removed.

Subjects were then presented with six statements from the flyer and were asked if they were true or false, as well as if they intended to get the flu vaccine and if they felt at risk of contracting the flu.

When subjects were asked these questions immediately after reading the flyers, both the myth/ fact flyer and the flyer with myths removed had their intended effects: Subjects in both groups were able to separate myths from facts, and they showed increased intentions of getting the flu vaccine.

However, one half- hour after reading the flyers, subjects who read the CDC’s myth/ fact flyer were no longer able to distinguish the myths from the facts — indeed, they began to misremember the myths as facts. Even worse, their intentions of getting the flu vaccine fell dramatically, and they were much less likely to believe themselves at risk of contracting the flu.

In an effort to explain these results, Skurnik and his colleagues suggest that “people are more likely to remember the gist of the statement” than whether it is presented as true or false. Furthermore, “once the memory for substantive details fades, familiar statements are more likely to be accepted as true than to be rejected as false.”

Given this tendency to remember things as true rather than false — a phenomenon the authors dubbed the “illusion of truth” — “repeating misinformation in order to discredit it can paradoxically enhance its perceived truth.” Consequently, the authors advise that “information campaigns should focus on the facts, avoiding any reiteration of the myths.”

Now of course, this one study does not provide conclusive evidence that myth/ fact campaigns are counterproductive in all circumstances. But since we have no evidence that such campaigns achieve their intended aims, there seems little reason to continue using them.

We do, however, have evidence that an alternative approach works better. And for that reason, the Canadian Cancer Society, and every other medical group, ought to replace myth/ fact campaigns with approaches that emphasize facts without myths — that once and for all tell the public the truth, the whole truth and nothing but the truth.