In Denial

Political scientist Brendan Nyhan was on All In with Chris Hayes last night (March 11) for a discussion of the Julia Boonstra television ad. The political ad, which was financed by the Koch Brothers' PAC, Americans for Prosperity, is running in Michigan in an early attempt to discredit Democratic Senatorial candidate Gary Peters. In it, Ms. Boonstra, a cancer patient, claims that her health insurance was cancelled due to the Affordable Care Act, that she can't afford the alternative policy offered to her, and that she is afraid she will die as a result. The ad was awarded three Pinocchios by the Washington Post after it was discovered that the alternative policy actually would save her $1200 a year. Her response was, “I personally do not believe that,” and that it “can't be true.”

This ad is part of a larger campaign in which Republican organizations trot out Obamacare “victims” to tell stories that are almost always misleading. Journalists eventually debunk these stories, but many more people hear the lie on television than read the truth in a newspaper, and even those who are told that the story is false often refuse to believe it.

Brendan Nyhan has been doing research for several years which shows that attempts to correct misinformation fail when they oppose people's deeply entrenched political ideologies. In fact, they can backfire and produce a boomerang effect—attitude change in the direction opposite to that intended by the speaker. Dr. Nyhan's latest study, released just last week, was an attempt to dispel the myth popular among conservatives that the measles, mumps and rubella vaccination (MMR) causes autism. Here's some background on the controversy from Aaron Carroll.

In the study, a nationally representative sample of 1759 young parents were randomly assigned to receive one of four pro-vaccine messages or a control message, delivered via the internet. The pro-vaccine messages, all taken from the Center for Disease Control (CDC) website, were:

1. Autism correction—written scientific evidence debunking the vaccination-autism link.
2. Disease risks—written descriptions of symptoms and risks associated with measles, mumps and rubella.
3. Disease narrative—a dramatic narrative in which a mother tells how her baby almost died from the measles.
4. Disease images—photographs of children suffering from symptoms of the three diseases.

The control group received an article about the costs and benefits of bird feeding. Nyhan measured the belief that the MMR causes autism, the belief that the MMR has serious side effects, and whether the participants intended to have their next child vaccinated, both before exposure to one of the messages and again about two weeks later.

The results were disappointing. Compared to the control group, the autism correction message significantly reduced the belief that the MMR causes autism. That was the only intended effect. The other three significant results were all boomerang effects. The disease narrative increased the belief that the MMR has serious side effects. The disease images increased the belief that the MMR causes autism. And finally, the autism correction resulted in parents reporting that they would be less likely to vaccinate future children. This latter effect was strongest for those parents who initially believed that the vaccine causes autism.

Ordinarily we should not make too much of studies that demonstrate no significant change. After all, the CDC messages could have been ineffective for a variety of reasons not immediately apparent to a reader of the study. It's also possible that different messages or combinations of messages might have worked. However, these were statistically significant backfire effects, and they should probably be taken seriously. The tendency of beliefs to persist or grow stronger even when the evidence for them is shown to be false is known as belief perseverance. The widely-accepted explanation for perseverance effects is self-persuasion. When people hear a message they disagree with, they counterargue with it. In the process, they expose themselves to their own counterarguments and persuade themselves to change their attitudes in the opposite direction from the message.

In the short run, at least, social scientists are becoming known in the media for delivering a depressing message: Factual information is ineffective in changing people's ideologically-motivated attitudes. So far, we have been unable to propose effective strategies for breaking through the barriers imposed by politically-inspired misinformation.

You may also be interested in reading:

Death By Anecdote, Part 1

The Open and Closed Mind

Motivated Reasoning