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.
Related Posts
- Informational Resources on Vaccine Safety
- An Open Letter to Parents Concerned About Vaccines
- On Explaining the Safety of Vaccination
Most Recent JREF Essays
good post. you are right, As the science behind vaccine safety is sound
I generally agree with your point of vaccination safety. However this quote from you disturbs me a little:
Vaccines are not 100% safe. We can only say that adverse reactions (which do happen) are amazingly rare. [Indeed, even if an order of magnitude more children were in some way harmed by vaccines, the cost-benefit analysis would still point to continued vaccination]
In your edge-case scenario, here is what you’re basically saying: Show to someone a room of 100 children and say: “If I don’t give them the vaccine, 10 will die. If I do, only 1 will die.”
On the surface, the choice may seem obvious — go with the lesser of two evils. However, this is not a full cost-benefit analysis, as you imply. Think deeply and you will discover other factors, such as “Do No Harm” and the cost of vaccine research, production, and distribution. (And, “death” is an extreme outcome, for which lesser problems are often the result.) There are many factors which complicate the decision to vaccinate.
Steve, my point was that out of an incredible amount of vaccines administered each year, a negligible percentage of them result in a VAE (and the majority of these are minor like soreness at the injection site). In fact, out of the 36.8 million H1N1 doses given in 2009, for example, 2365 VAE cases were reported. This is only .006% of the total doses given, and practically insignificant. 95% of these cases were benign, with 8 deaths that had no relation to vaccination itself. Even if you increase these percentages by an order of magnitude, the intervention is extremely safe.
I do not agree with your analogy. Surely the additional cost-benefit parameters that you are imposing apply to all the children. Therefore, as a medical intervention, it would still be perfectly dependable to argue for all the children to be vaccinated, even if one child may experience a VAE. In the face of statistics which show the overwhelming safety of vaccination and their effectiveness, I would find it hard to argue that “the cost of vaccine research, production, and distribution” outweighs saving millions of lives.
Though I’ll admit that I was being a tad utilitarian in my quote you referenced.