Vaccinating, metaphorically and literally

There’s a lot of bad (either misleading or blatantly false) science information on the Internet. Science communicators often try to combat the bad content by dumping as much accurate information as they can into the world, but that strategy is not as effective as many would hope. One reason it’s not effective is that social circles on the Internet are echo chambers: people tend to be follow like-minded others. Scientists and science communicators follow each other, and skeptics follow each other, so we rarely even hear what others outside our circle are talking about. Plus, when we do encounter evidence that contradicts our beliefs, we tend to discount it and keep believing what we already did.

A recent study by Sander van der Linden, Anthony Leiserowitz, Seth Rosenthal, & Edward Maibach (that I recently wrote about) gives a glimmer of hope to this science communication trap: communicators may be able to “vaccinate” their audiences against misinformation. They found that if people are cued in to the kinds of tactics that opponents of global warming deploy, they’re less likely to believe them. This finding offers some hope in a time when the proliferation of fake and misleading science information seems inevitable. Scientific facts, along with a heads up about anti-scientific strategies, can help people better evaluate the information they receive to form evidence-based beliefs and decisions.

Does this apply to other scientific issues? Can we vaccinate against anti-vaccination rhetoric?

I don’t know. But I’d like to find out. In order to design a communication that alerts people about anti-vaccine messages they might encounter, it’s important to understand anti-vaccine tactics. I explored some very passionate corners of the Internet (videos, discussion threads, and blog posts by anti-vaccine proponents) for a better understanding. Here are the anti-vaccine tactics I found, a lot of which are described in this SciShow video:

Ethos: Appeal to Authority

First, note that this immunologist isn’t explicitly saying that children shouldn’t be vaccinated. But the quote implies so much. I don’t know if that’s actually her belief, but regardless, as a consumer of this image, I do get the sense that she looks pretty smart (#educated, in fact), and maybe she knows what she’s talking about…


Screen Shot 2017-03-11 at 9.32.35 AM

There are four chemical names in the first five lines of the ad above. It sounds like whoever wrote it must really know their science. The message implies that the author has deep scientific knowledge about the chemicals mentioned and wants to warn you of their presence in vaccines. Paired with our society’s tendency to believe that all things “natural” are good, and all things “chemical” are enemies, this jargon-wielding author might appeal as someone worth listening to. Most of us (and I am definitely included here) don’t know much or anything about those chemicals — how do they work? Are they actually dangerous in the doses found in vaccines? This jargon paves the way for persuasion through the naturalistic fallacy — the idea that all natural things are better than non-natural things.

Logos: Appeal to “Logic”

Logical fallacies

A logical fallacy is faulty logic disguised as real logic, and it’s another common tactic used by anti-vaccine proponents. In the Tweet above, the author presents two facts, implying that they’re connected (that an increase in mandatory vaccines led to a change from 20th to 37th in the worldwide ranking of infant mortality rates. Just because America “lost ground” on this ranking, it doesn’t necessarily mean our mortality rate even went up — it’s likely that many other nations’ mortality went down. Plus, there are so many other factors beyond number of mandatory vaccines that influence infant mortality rate, and no evidence supplied by the Tweet that vaccines and mortality are related. They’re just two pieces of information, placed next to each other to give a sense of a causal relationship.

There are lots of ways logic can be distorted to suggest that vaccines are bad. One that really stands out to me is the suggestion that if vaccines work, why should we care if some children are not vaccinated? After all, they’ll be the ones who get sick… why does it concern the rest of us?

It does. For one, no child should end up with a paralyzing or fatal disease because their parent chose to disregard scientific consensus. But one person’s choice not to vaccinate directly affects others — for example, people who CAN’T be vaccinated for health reasons. If everyone else receives vaccines, that one person who cannot is safe thanks to “community immunity.” But if others stop receiving those vaccines, the person who had no choice but to remain unvaccinated is susceptible. This person is unjustly at danger as a result of others’ choices.

Pathos: Appeal to Emotion


Fear is a powerful motivator. Appeals to ethos and logos can work together to have an emotional effect. Parents just want to do their best for their kids, so messages that strike up fears about the harms of vaccines have a good chance of swaying them.

One way of drumming up fear is to promote vaccine proponents as bullies, as this article demonstrates:

Screen Shot 2017-04-30 at 1.08.20 PM.png

Yea, that description sounds pretty scary to me… Breakdown Radio. Link to article

Considerations for inoculation messages

Of course, I’ve just scratched the surface with these tactics that anti-vaccine proponents use (you can get an idea of some others in a post on how the anti-vax movement uses psychology to endanger us by Dr. Doom) Messages that vaccinate against misconceptions have to walk an extremely fine line. The goal of such a message is to foreshadow misleading messages a person may encounter, and to point out the reasons that message should be reconsidered.

Vaccine messages might be useful when they introduce new information, but they also need to be proactive, anticipating anti-vaccine rhetoric and alerting people to its flaws. There are a few dangers in doing so, though. For one, it often requires repeating the misconception, and research shows that doing so can backfire and reinforce the inaccuracy instead. In addition, pointing out flaws in an argument that someone might be prone to believing can alienate that person. If the warning message isn’t constructed conscientiously (for example, if it suggests that seeing through the misleading information is a no-brainer), it can imply that anyone who might believe the misconceptions is an idiot. A message like this will make some members of the audience feel defensive (wow, am I an idiot? No, I can’t be an idiot. Maybe this author of this message is the idiot…).

That doesn’t mean that inoculation messages can’t be effective. We have some evidence to suggest they can, and I think there’s a lot of room to continue honing this strategy. The first step in a successful inoculation message is to uncover the tactics used by those who misrepresent the science. Then it’s important to raise awareness of those tactics without alienating the audience and while being careful not to repeat the misinformation in a way that can be construed as reinforcing it.

Communicators can keep in mind that anti-vaccine messages often attempt to establish authority, tap into emotions, and apply misleading logic in order to convince people of their message. By anticipating these strategies, we can have greater success in counteracting them and promoting vaccines as the life-saving technologies they are.

More information