I have excerpted my latest essay for the James Randi Educational Foundation (JREF) below. In it I take a look at a recent study which found that, counter intuitively, the stronger we word our arguments that attempt to beat back harmful anti-vaccine propaganda, the more we raise people’s perception of vaccine risks. Below I explore the study and then offer some strategy on how to overcome this negativity bias.
You can find my other long form essays for the JREF here.
How Should We Argue For Vaccination?
Back in March a study came out, though it was only recently hyped up in the media, which explored an interesting intersection between psychology, vaccination, and the communication of risk. This study by Cornelia Betsch and Katharina Sachse (2012) covered two experiments in which the researchers looked at how the wording of vaccine risk messages affected participants’ perception of the safety of vaccines.
The idea of these experiments was to explore what the researchers call the negativity bias. This bias is a tendency for negative messages to influence our perceptions of risk more than positive ones. This creates a problem for the communication of negating messages—messages that downplay a risk or offer contradictory evidence against a risk. So, relating to information about vaccines, how strongly should we word our pro-vaccine arguments?
As the science behind vaccine safety is sound, there are a few ways to make an argument for it (and to argue against anti-vaccine pseudoscience). The study outlines two different tactics: strong risk negation and weak risk negation. The study offers up the following example of both:
The claim that newborns tolerate vaccinations less well than older infants may be negated by the statement “It is absolutely impossible that newborns tolerate vaccinations less well than older infants,” which may be perceived as a strong and confident negation. A weaker risk negation may be expressed by the following statement: “It is extremely rare that newborns tolerate vaccinations less well than older infants.”
Participants in the experiments were asked to imagine that they were parents unsure about vaccination and its side effects, and were then presented with a number of common anti-vaccine arguments and their corresponding strong or weak negations (rebuttals). After this, the participants were asked how likely they would be to vaccinate their imaginary child against a fictitious illness. We could imagine this to be exploring how people would respond to the science-based community’s debunking of anti-vaccine myths.
- Informational Resources on Vaccine Safety
- An Open Letter to Parents Concerned About Vaccines
- On Explaining the Safety of Vaccination
Most Recent JREF Essays
- An Introduction to Human Information Processing (Part 2)
- Living Without Free Will
- Risk, Emotion, and Global Warming