Anti-Vaxxer Evidence

Virtually no one goes through life thinking, “My beliefs about the world are driven by irrationality and heuristics.”

No, we all fancy ourselves to be rational.

Regardless of what we believe, we believe the evidence is on our side.

Take John and I, for example.

John is certain that the measles, mumps, and rubella vaccination causes autism. But I believe John is wrong. I have evidence that John is wrong: if you look at the people in a population who are diagnosed with autism, there is no statistical difference between those who received vaccinations as children and those who did not. Epidemiologically, there is nothing that connects vaccinations to autism. (i.e. Taylor et. al 1999, etc.)

What is correlated with parents not vaccinating their children? Well, outbreaks of measles, for one. (CDC)

But my evidence is meaningless to John. Why? He believes different evidence. John’s evidence might be anecdotal (à la Jenny McCarthy), or intuitive (he’s got a hunch), ideological (don’t interfere with ‘nature’), conspiratorial (it’s all a government cover up), or unfortunately widespread misinformation (as per Andrew Wakefield). Whatever the case, John does not think to himself, My beliefs about vaccinations are irrational. No, he’s got his reasons. And he is convinced by them.

He is committed to his evidence as much as I am to mine.

As far as I can tell, given the data and evidence as I see it, John’s refusal to vaccinate his child is both irrational and irresponsible. But according to John’s evidence, he believes he is making the best decision for his child. He believes it dearly.

John and I both have our evidence, and this is the problem. Scientific, peer-reviewed, data-driven evidence is clearly only one kind of evidence — and it is a kind of evidence that John out-rightly rejects. John is so convinced by his reasons — whatever they are — that it doesn’t matter what I think.

Therefore, it is pointless for John and I to debate vaccinations. I think he is ignoring basic science. He suspects that I am deluded by blind trust in the scientific establishment. We are at an impasse. It does not matter how emphatically I drone on about ‘evidence-based medicine’, falsifiable propositions, and the null hypothesis. John is having none of it. All of this is important to me, but not to him.

John is no sooner going to entertain the validity of my evidence than I am going to accept the validity of his. I seek to surrender my intuitions to the probabilities of empirical observation, and I strive to change my position as new data emerges (especially at such a large scale of consensus). Let’s be honest: John is probably not going to talk me out of these methodological convictions. “That’s what you believe is true,” he acknowledges. “But that is not what I think and feel about the issue.”

If I am going to convince John to vaccinate his child, I need to either help him change his functional definition of evidence itself or present an appealing counter-narrative in his language — a story told in his current ‘category’ of ‘evidence.’

Herein lies the dilemma of health promotion: ‘evidence-based research’ alone has never changed the minds or behaviours of people (or policy-makers) not already convinced of the validity of quantitative data.

Before John and I can have a meaningful conversation about vaccinations, we need to have a meaningful conversation about the nature of falsifiable propositions. And this needs to be a conversation, not a monologue correcting the ‘errors’ of his evidence. I cannot change John’s convictions and conceptualizations about the nature of evidence any more than I can change his deepest hopes and dreams.

I now view the anti-vaccine movement as a sort of cult, where any sort of questioning gets you kicked out, your crunchy card revoked. I was even told I couldn’t call myself a natural mother anymore, because vaccines are too unnatural. That’s fine. I just want to be the best parent I know how to be, and that means always being open to new information and admitting when I’m wrong. (Leaving the Anti-Vaccine Movement by Megan Sandlin)

This is the bottom line: I cannot change John’s mind. Only John can change John’s mind. If I accept this premise at the outset of our conversation, my interaction with John will be markedly different than if I were to presume myself capable of correcting John’s thinking for him.

After all, I am just like John: if you are going to convince me that vaccinations cause autism, you will have to show me evidence that I accept as valid — the kind of evidence I already use and trust to make sense of the world I live in.

John and I are so different. John and I are exactly the same.

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The Antidote to Pseudo Science?

Who can you believe when everyone claims that “science” is on their side? This question has been preoccupying me lately. It strikes me as a fundamental issue at the heart of many policy debates today, especially environmental ones.

Quite by accident, this week I came across an article entitled Between complacency and panic by Philip Handler and Alexander Zucker. (It seems to be publicly unavailable online, but I was able to dig up a copy from the archives at the university.) Published in 1973, the article is a little dated, but highly prescient of the role that science might go on to play in political and ideological standoffs.

Consider just about any hot-button issue related to environmental policy:

Out of a great melange of brutal immediacies, conflicting theses, and sometimes sheer nonsense, one must try to extract some generalized approaches to the problems of the environment. The first impression is an abundance of unrelated issues, a babble of voices, some raised in protest, others reassuring in calming tones; prophecies of doom–and grand schemes to alleviate these problems. (p. 1748)

When it comes to systemic, long-term environmental risks and threats, scientists find themselves in a permanently awkward position: raw data is never prescriptive until it is interpreted by a human, and yet data is not valuable to humans unless it is interpreted.

Unfortunately, “risk/benefit analysis” is a facile phrase rather than an established science and, in the end, even with adequate data will usually turn on value judgements. (Ibid 1749)

Ergo, science finds itself inseparable from morality: the genuine scientist must walk a line of “absolute integrity” by clearly emphasizing the limit of her knowledge to the issue at hand. What she admits to not knowing is equally as important as what she declares to understand.

Scientists are now asked to forecast answers which they not only do not have, but see little hope of obtaining within the limits of present knowledge and technique. The individual scientist must then frankly admit the limits of his present knowledge and understanding, but at the same time, so as not to be counted out of the councils of decision-makers, he must say, “I don’t know the answer, but I know the reasons for my ignorance and I do know quite a bit about how the problem should be approached.” This difficult role demands absolute integrity on the part of the scientist. If not clearly understood, science, as well as the scientist, becomes vulnerable to attack by policy makers. (Ibid 1752)

When science fails to declare its ignorance on issues, it risks devolving into a blunt, ideological weapon. This, argue the writers, will lead to a situation that seems eerily similar to our world today: policy-makers and the public at large are left to choose between opposing “scientific views” on almost every issue. “The science clearly shows…” is quoted by both sides, with equal conviction and vigour. Predictive models predict opposing outcomes. The validity of peer-reviewed science becomes solely a question of who one’s peers are. The nature of scientific inquiry becomes an inquiry into who funded the research.

Science, in other words, becomes a battleground. “The science says” turns into a rhetorical tool for just about any argument. What good is “science”, then, if it fits in the arsenal of every propagandist and can be used to validate just about any proposition?

Here we reach the crux of the problem: if science can be so confidently cited and quoted by opposite arguments, why bother listening to science at all? How can you and I, average citizens that we are, ever hope to tease out the honest science from all the pseudo science? How can those of us without expertise choose which expert to listen to?

Is there an antidote to pseudo science?

True expertise on a subject not only includes comprehensive knowledge, it also entails an equally extensive understanding of the questions, gaps, and holes in the data… and an unyielding appreciation for the exhaustive nature of the unknown beyond them. These points of ignorance are as important to the scientist as her hypotheses, discoveries, and conclusions. When she speaks “from the pulpit of science” — especially to the public and to policy makers — she must disclose her lack of expertise as well as to her knowledge.

This overt disclosure of uncertainty is the moral code of science. Handler and Zucker argue that this “ethic” must be “enforced by the scientific fraternity” if science is to continue to have any relevance at all. (Ibid 1752) When science shirks away from its uncertainties, it loses validity.  Ultimately, the consequence of making science exclusively about answers and expertise is that science will ultimately become pointless in the public sphere, for it devolve into a meaningless game of  “My science is right. His science is wrong. Believe my science.”

we run the risk that scientific advice will no longer be sought because responsible laymen will find it too difficult to establish who represents science on which occasion–a steep price indeed! (Ibid)

Those of who us who wish to integrate some semblance of scientific rigour into policy consideration need to do a difficult thing: admit everything we don’t know. We need to not only admit uncertainty, we need to advertise our ignorance. Admittedly, in a world of polarized opinion on issues with high-stake consequences, this strategy might seem counter-intuitive. Indeed, many of us have become obsessed with the cause of bringing robust empiricism to triumph over cherry-picked results. But this is just the point: if we want science — true, honest, open science — on the table of policy-makers, we need to get over our preoccupation with winning arguments. This only makes our discipline irrelevant.

Science is laced with contingencies. Pseudo science claims to possess indisputable answers.

The antidote to the declining relevance of science in public discourse is not to madly insist that “science has the answers”, but to also unapologetically expound the woeful inadequacy of what we presently know.

At least, this is one hypothesis.

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