Anti-vax: wrong but not irrational


Since the uptick in outbreaks of measles in the US, those arguing for the right not to vaccinate their children have come under increasing scrutiny. There is no journal of “anti-vax psychology” reporting research on those who advocate what seems like a controversial, “anti-science” and dangerous position, but if there was we can take a good guess at what the research reported therein would say.

Look at other groups who hold beliefs at odds with conventional scientific thought. Climate sceptics for example. You might think that climate sceptics would be likely to be more ignorant of science than those who accept the consensus that humans are causing a global increase in temperatures. But you’d be wrong. The individuals with the highest degree of scientific literacy are not those most concerned about climate change, they are the group which is most divided over the issue. The most scientifically literate are also some of the strongest climate sceptics.

A driver of this is a process psychologists have called “biased assimilation” – we all regard new information in the light of what we already believe. In line with this, one study showed that climate sceptics rated newspaper editorials supporting the reality of climate change as less persuasive and less reliable than non-sceptics. Some studies have even shown that people can react to information which is meant to persuade them out of their beliefs by becoming more hardline – the exact opposite of the persuasive intent.

For topics such as climate change or vaccine safety, this can mean that a little scientific education gives you more ways of disagreeing with new information that don’t fit your existing beliefs. So we shouldn’t expect anti-vaxxers to be easily converted by throwing scientific facts about vaccination at them. They are likely to have their own interpretation of the facts.

High trust, low expertise

Some of my own research has looked at who the public trusted to inform them about the risks from pollution. Our finding was that how expert a particular group of people was perceived to be – government, scientists or journalists, say – was a poor predictor of how much they were trusted on the issue. Instead, what was critical was how much they were perceived to have the public’s interests at heart. Groups of people who were perceived to want to act in line with our respondents’ best interests – such as friends and family – were highly trusted, even if their expertise on the issue of pollution was judged as poor.

By implication, we might expect anti-vaxxers to have friends who are also anti-vaxxers (and so reinforce their mistaken beliefs) and to correspondingly have a low belief that pro-vaccine messengers such as scientists, government agencies and journalists have their best interests at heart. The corollary is that no amount of information from these sources – and no matter how persuasive to you and me – will convert anti-vaxxers who have different beliefs about how trustworthy the medical establishment is.

Interestingly, research done by Brendan Nyhan has shown many anti-vaxxers are willing to drop mistaken beliefs about vaccines, but as they do so they also harden in their intentions not to get their kids vaccinated. This shows that the scientific beliefs of people who oppose vaccinations are only part of the issue – facts alone, even if believed, aren’t enough to change people’s views.

Reinforced memories

We know from research on persuasion that mistaken beliefs aren’t easily debunked. Not only is the biased assimilation effect at work here but also the fragility of memory – attempts at debunking myths can serve to reinforce the memory of the myth while the debunking gets forgotten.

The vaccination issue provides a sobering example of this. A single discredited study from 1998 claimed a link between autism and the MMR jab, fuelling the recent distrust of vaccines. No matter how many times we repeat that “the MMR vaccine doesn’t cause autism”, the link between the two is reinforced in people’s perceptions. To avoid reinforcing a myth, you need to provide a plausible alternative – the obvious one here is to replace the negative message “MMR vaccine doesn’t cause autism”, with a positive one. Perhaps “the MMR vaccine protects your child from dangerous diseases”.

Rational selfishness

There are other psychological factors at play in the decisions taken by individual parents not to vaccinate their children. One is the rational selfishness of avoiding risk, or even the discomfort of a momentary jab, by gambling that the herd immunity of everyone else will be enough to protect your child.

Another is our tendency to underplay rare events in our calculation about risks – ironically the very success of vaccination programmes makes the diseases they protect us against rare, meaning that most of us don’t have direct experience of the negative consequences of not vaccinating. Finally, we know that people feel differently about errors of action compared to errors of inaction, even if the consequences are the same.

Many who seek to persuade anti-vaxxers view the issue as a simple one of scientific education. Anti-vaxxers have mistaken the basic facts, the argument goes, so they need to be corrected. This is likely to be ineffective. Anti-vaxxers may be wrong, but don’t call them irrational.

Rather than lacking scientific facts, they lack a trust in the establishments which produce and disseminate science. If you meet an anti-vaxxer, you might have more luck persuading them by trying to explain how you think science works and why you’ve put your trust in what you’ve been told, rather than dismissing their beliefs as irrational.

The Conversation

This article was originally published on The Conversation.
Read the original article.

11 thoughts on “Anti-vax: wrong but not irrational”

  1. That last line..applies to conversations with creationists, conspiracy theorists and pretty much anyone who has a handle on the facts which is, all things considered, in violent disagreement with the best scientific perspective available.

    Strained attempts to emulate Sir Humphrey Appleby aside, I totally agree.
    In recent years, I find it much more fruitful to, in the event of a disagreement in which I have a scientific position to defend or advance,steer the discussion towards an examination of “how the other person came to her/his conclusions” and taking it from there. Patience is key.
    Dismissive attitudes do not help anybody (unless, of course, the BS-meter is screaming for air and we cannot abide that).

  2. Superb article. There is a way to approach these people, and a lot of the resistance is the fault of the “Skeptics” who shut down the conversation. Saying benefits outweigh the risks is not the same as saying “vaccines are safe so stop being so ignorant”. Some flu vaccines in the UK put some children at risk for narcolepsy. And this is a problem with adjuvants, which have been eliminated because yes, they put people at risk. Same with rabies vaccines in cats – FVRCP is now injected in the leg. Why? So they can amputate in the rare case that the adjuvant causes sarcoma. Skeptics who say there’s zero risk are lying just like anti-vaxers think Big Pharma are doing cover ups. So yes, answer their questions and make it about vaccines saving lives. They’re allowed to ask questions. This is not a cult.

    Too bad there’s not so simple of an answer for climate change! The journal Environmental Politics seemed to suggest in a study that only Tea Partiers deny climate change more as their education increases – but maybe it’s immaterial when it comes to persuasion.

  3. One of my best friends is an anti-vaxxer, an alternative medicine believer and holds a very negative view of the pharmaceutical industry, the government and main stream media. We could call her a conspiracy theorist probably. Your analysis seems to fit her perfectly. Except that there is no argument coming from me that was ever able to change her opinion. In the end, I’ve chosen to respect her opinion and her freedom of choice. And I won’t be mad at her if I ever catch measles while on chemotherapy. Life is a rocky ride we can’t control. It’s silly to fight over whether we should try or not. Better, just try to enjoy the ride.

  4. With respect to both anti vaccination and climate change denyers…

    I wouldn’t go with irrational either…

    Irresponsible is way more accurate. There are consequences to the actions/inactions of both. And it’s usually others who suffer.

    Not sure how much of either conversation I can handle anymore though. It’s exhausting and non productive.

    1. I do agree that it irresponsible. Anti-vaxxers should consider the immediate problem at hand which is the virus spreading. The possibility that a child will become sick from a virus immediately is more likely than becoming autistic years later.

      Advocates argue that thimerosal in vaccines are causing an increase in autism in children but the thimerosal have been removed from most vaccines since 1992, yet the rate of autism continued to rise. This is because there are many factors that contribute to autism in children such as genes and environmental toxins,not just vaccines.

      We can’t continue to live in fear, rather prevent what we can at this moment and deal with problems that arise later on.


  5. yes, has been my experience that anti-vaxxers now concentrate on “freedom of choice” issues, trusting to figures who apparently are defending freedom, standing on the edge of the slippery slope to compulsory medication of all sorts.

  6. Very disappointed with this one Tom.

    Paragraph one – Let’s use buzz-term ‘anti-vax’ and over-generalize these people as holding an anti-science (whatever that means) and dangerous position. Can see what direction this is heading.

    Science is a process by which ‘conventional scientific thought’ is challenged and refined. Dogmatism is….
    I like anti-evolutionists; they come up with clever ways to help me clarify my own ideas to the opposite.

    “Climate sceptics” – think about that for a moment, do you have any proper words to clearly state what you’re trying to say.

    Are you seriously suggesting that we should “put your trust in what you’ve been told” because it comes from a scientist. Try and imagine that world for a moment!

    The point where the risk of not vaccinating outweighs the risk of vaccinating varies widely amongst demographics – googled info – not there – not to worry, can trust big pharma. “Science” would be making this information and the method by which it was arrived at available.

    The fact that the term “Climate sceptics” exists suggests a dysfunctional scientific and political climate.

    “By implication,…” You’re either with us or against us.

    “… matter how persuasive to you and me …” Presumptuous

    Seems like Orwell’s “Four legs good, two legs bad” to me.

    Hang on – now I get it – you’re using readers as part of an ingeniously designed persuasion / gullibility experiment!

  7. @chris – I am seriously suggesting that, when faced with people with whom you disagree, explaining why you believe something is more productive than reiterating what you believe with more and more force

  8. This has to be the worst and most biased article I’ve ever read on here. This is not a psychological issue and whether a person wants to vaccinate or not is none of anyone else’s business. That being said, this is also the worst propaganda.

    Climate change is not real. It should be pretty obvious to everyone by now but hey, tv says it’s real so it must be true. Nothing beats the human ego.

    Vaccines are harmful, period. If you don’t believe that the connection between autism and vaccines exists, just look at the numbers. 30 years ago 1 in 25000 kids get autism. Now, 1 in 100 in Canada and 1 in 42(boys) in the U.S. That’s enough to make you wonder, isn’t it? Not to mention the doctor that initially found this is getting his medical licence back and is being exonerated. Other doctors have spoken out. It is stupid to think these drugs aren’t harmful. Read the insert that comes with them at the doctor’s office. You will see just how bad the side effects can be. Have you ever seen a drug on tv, they list the side-effects, and you think to yourself that it’s not worth it? Same thing here. If you knew.

    Anti-vaxers and climate change deniers might just know a little more about the “science” than you do.

    It is egotistical of you to say they are wrong when you don’t know any better.

  9. It’s amazing people are so up in arms over one time vaccines and not the least bit concerned over their pets. When I wanted an update on measles, my doctor said not without a blood test, because it’s risky to over vaccinate. Same with rabies (yes, I’m vaccinated) I was told a booster too soon would “overstimulate the immune system”. Yet while doctors are telling me to not get at total of 2 vaccines too close together, our pets are being given a rabies vaccine every single year for their entire lives. Doesn’t this concern anyone?

    (And by the way, if people like anecdotes – the one vaccine on this planet I haven’t had was whooping cough. My mom heard stories that the vaccine wasn’t safe. Guess what I almost died from at 3 months old when my older sister contracted it).

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