Strong, but weakly held
When we are convinced that we are right, it is tempting to crank up our determination, making us stray into the land of fallacies. But we can avoid this!
I am of an age to still have the visible signs of my smallpox vaccination, though the sands of time have done their best to erode the scar away. (In those days, boys got their vaccination administered on the outside of their upper arm, while girls got theirs on the inside, as they were assumed to be more likely to wear tops that would expose their arms all the way to the shoulder. O tempora…) That small scar was, of course, an opportunity for curious children to ask what this was all about, and many parents – like mine – will have explained the purpose and the benefits of vaccination. Hardly a decade later, the eradication of the disease thanks to mass vaccination reinforced to my youthful mind its remarkable power. Vaccination was a near-miracle, and an unconditional must.
A stretch too far
But is it? A few days ago, the economist Bryan Caplan tweeted that he had refused his physician’s offer of a tetanus booster, on the basis that it kills no more than two Americans per year (that is 1 in more than 150 million, or about half the likelihood of being killed by an asteroid). It attracted many hundreds of comments, many of them derogatory, such as “My flight instructor talked to me like a child when I refused a parachute. Death from skydiving only causes a handful of deaths per year!”, and “You just failed an intelligence test and shared it with us.” These disparaging reactions likely had their origin in a strong pro-vaccination conviction (such as the one I grew up with, as vaccines safeguarded me not just from smallpox, but from several other dangerous diseases – I did contract measles, though!).
What of the parachute counterargument, however, that suggests it is thanks to the vaccination that fewer than three Americans per year die from tetanus? According to the American Centers for Disease Control and Prevention (CDC) around 63% of the population have had a booster in the last 10 years. That leaves more than 1 in 3 – well over 100 million of Americans – unprotected (and, given that the CDC statistic is based on self-reporting, this is probably an underestimate). The vaccination status of the other two thirds is of no relevance, as tetanus, importantly, is not a contagious disease. It is also instructive to note that the number of tetanus cases (rather than deaths) in the US fluctuates around 25 per annum which, out of an unvaccinated population of roughly 115 million, or about 1 in 4.6 million (that is comparable to the risk of dying in a car collision during a 50-mile/80km journey).
As a good economist (who is also not remotely against vaccination), Caplan looked at the benefits and costs, and found the doctor’s argument wanting for reasons of innumeracy. As he concludes a short blogpost on the topic, “When you do math, changing the numbers often changes the right answer”, and “Whenever doctors urge you to suffer, check the numbers, because they probably won’t.”
It occurred to me that there was more than a little irony in the fact that those who reacted critically and disdainfully to Caplan’s tweet appeared to be just as dogmatic as antivaxxers are in the perception of people who are pro-vaccination. Vaccination is good – very good indeed, in some cases – but that does not exempt it from scrutiny. The responses seemed to be a case of hasty generalization (“vaccines are good for in some cases, so they are always good”) and motivated reasoning (“somebody who refuses vaccination must be a flawed thinker, therefore Caplan’s reasoning is flawed”, and “vaccination is good, therefore the argument contradicting it must be faulty”).
Strong (conditional) beliefs
It is hard not to see at least a touch of hubris and condescension in this attitude, and this very likely stems from a strong opinion, rooted in a (perceived) rational, evidence-supported basis, and easily amplified by additional factors. As all of this played out on what most people still refer to as Twitter, widely known as a tribal environment, a post like Caplan’s offers opportunities to score reputation points with like minded pro-vaccination evangelists. Piling on an apparently dissenting opinion gains you more credit than a critical attitude that genuinely questions whether the dissenter might have a point. Showing off that you are right feels good, doing so in the (virtual) presence of like-minded individuals all the more.
There is also an individual dimension to this. A strong belief held since childhood, confirmed time and time again, tends to become associated with one’s identity. An apparent threat, especially from someone with as much clout as Bryan Caplan, has the potential of triggering an intense reaction, an urge to take up its defence.
Altogether not a good show, unfortunately. A dogmatic pro-vaccination stance can come across as patronizing, and alienate those who are on the fence or seeking insight. It could also cause moderate vaccination ‘sceptics’ to intensify their doubts into a full-blown anti-vaccination attitude. Poor reasoning can harm personal credibility – and indeed that of the scientific community around vaccination: dogma is rightly seen as antithesis to scientific thought.
Strong convictions tend to suppress intellectual humility, just like someone in a position of great power might find acting humble doesn’t come naturally. Why be humble when you know you’re right? Cultivating a mindset that recognizes the limits of one’s knowledge is a good starting point, as is steering clear of an absolutist viewpoint and adopting a more nuanced position in general.
The futurist Paul Saffo once wrote an essay (which has disappeared from his website, but thankfully it was captured by the Wayback machine), in which he advocates Strong opinions weakly held. Make sure your opinions are strong – clear and specific, as persuasive as they can be and backed by evidence. But be ready for them to be challenged, and prepared to ditch them for something better or to cut their scope down to size to avoid overgeneralization. Do not grow attached to them and do not allow them to define you. Opinions should not be part of your identity.
A sensible way to help with the ‘weakly held’ part is to explicitly identify and acknowledge the potential limitations of your convictions. It is wise to avoid choices that are never questioned and – when new circumstances call for it – reversed by setting out in advance what those new circumstances might be. In the same way, we can establish when vaccination might not be the no-brainer that we are convinced it is. Here, we might realize that key aspects of this conviction include the questions whether the disease is contagious, and what its incidence is. This avoids the absolutist thinking that makes us cling on to inappropriate beliefs, convictions and opinions.
Together with this principle, it makes good sense to always consider costs and benefits, as Caplan does. We may well be convinced that one dominates the other (or vice versa), but that should stand up to scrutiny, and not be a matter of faith. Focusing solely on the potential (and perhaps very minor or even imaginary) downsides of vaccination may be irrational, but so is focusing solely on the potential (and perhaps very minor or even imaginary) benefits.
Scoring points is easy, pursuing the truth takes more effort. Whether that is worth it, is up to us.