Measles, the Media and the Dunning-Kruger Effect

Syringe

The CFR has just released a map showing the incidence of vaccine-preventable diseases worldwide. You can click by VPD to see how different countries are doing by preventable illness. I find it entirely shameful that the UK ranks lower than most developing countries – but how can this have happened? Ever more studies like this one published by the CDC in the Journal of Pediatrics [sic!] confirm fears of a link between vaccines and autism are unfounded – this one just backs up the conclusions of so many other studies.

In the absence of any good data showing harm from vaccination, why do so many people still expose their and others’ children to preventable diseases that risk significant morbidity and even death? For example in the USA 1/3rd of parents believe vaccines cause autism and 1 in 10 parents refuse or delay vaccinations because they think know better than CDC doctors expert in the field.

Let me state my biases up front. 

I believe that sanitation and immunisation have transformed public health; more so even than antibiotics. And this isn’t blind faith; science is a culture of doubt, not faith and I think you’d be hard pressed to find anyone working in microbiology, public health or infection control who would disagree with me. Yes, better nutrition, education and lots of other things also play a part in our life expectancy being ~80 and rising whereas 100 years ago the average lifespan was only 45 – but the correlation between the disappearance of VPDs and the introduction of their respective vaccines cannot be explained away by hand washing and better sewerage.

Also I tend to give more weight to published data that I can review for myself so I can check for biases and fallacious arguments. Some journals are better than others and just because something has been published doesn’t necessarily make it true. That’s how science works – we publish our data so others can replicate and agree or challenge. It’s like a polite bar brawl and that’s why so many of us like it.  Some studies are better than others and there is some utter nonsense published in ‘learned’ journals – take a look at this for an example; it argues that quantum theory provides a model for the effectiveness of homeopathy (water). Lots of science-y words but it’s quite simply – to use the proper scientific term – Utter, Utter Bollocks (µ²B). More examples later.

Anyway, back to the point. There were recent cases in the American National Vaccine Injury Compensation Program (aka the ‘Vaccine Court’) that compensated two individuals based on gossamer-thin evidence which is being hailed as a ‘vindication’ of Andrew Wakefield. It isn’t and I’ll dissect that argument if anyone’s interested but let’s start with the MMR / autism link and the former Dr Wakefield.

Wakefield Lied. Children Died.

Tempting though it is to get into a huge ad hominem against this man let’s stick to the facts rather than fall prey to the logical fallacies such as ad homs that regularly feature in arguments against immunisation. The facts are:

  1. Two years before the infamous February 1998 Lancet article proposing a link between the MMR vaccine and autism Wakefield’s group was paid £435,643 in fees plus £3,910 expenses by solicitor Richard Barr, then of the firm Dawbarns looking to prove a link between MMR and autism for a class action against vaccine manufacturers.
  2. A year before the Lancet article Wakefield filed a patent for a single vaccine claiming a link between MMR, measles, irritable bowel syndrome and regressive behavioural diseases.
  3. While the Lancet paper was quite nuanced and circumspect in its claims Wakefield fuelled a media frenzy – with the results we are seeing now.
  4. He was later struck off for not revealing the conflicts of interest (1 & 2 above) as well as conducting unwarranted, unnecessary and unauthorised procedures on autistic children including colonoscopies and lumbar punctures.
  5. On 28th January 2010 the GMC described him as ‘dishonest’, ‘unethical’ and ‘callous’ and he was found guilty on 4 counts of dishonesty and 12 counts involving the abuse of vulnerable autistic children.

Wakefield is not the only one to blame; I’ll come to my disdain for the reporting of science in the popular meeja in a moment but if my central premise – that vaccines are hugely beneficial and Wakefield was a liar and a cheat who falsified data for personal gain – is correct why is he still viewed as a hero in some quarters and why do so many otherwise intelligent people find the whole anti-vaccine argument so persuasive?

Association, Anecdote, Advice, Advertisement

One thing that any scientist needs to do is to learn to evaluate data and not fall victim to the many logical fallacies out there that can lead us astray. For example, the Appeal to Antiquity so beloved of so many quack nostra: “…used for thousands of years…”

Would you want a thousand year old intervention or one that has recently been rigorously scrutinised and proven to be effective? Traditional Chinese medicine is a good example – used for thousands of years resulting in a life expectancy sub-40 until Western medicine came along. One of the most powerful logical fallacies is the fallacy of false cause. A subset of this is post hoc ergo propter hoc – or B came after A therefore B was caused by A. This is a very common fallacy but let’s stick with its relevance to autism and MMR.

Autism is often diagnosed at about the time the second MMR is given (3yrs and 4 months on the UK schedule). And when a diagnosis like that is given people always look for a cause. Something must be to blame. No matter how persuasive the post hoc fallacy argument might be logically, if a mother associates her child’s diagnosis with a vaccine that was administered a few weeks before, no one is likely to dissuade her. But association isn’t necessarily causation. I remember a first year stats question comparing live births in Denmark with stork distribution plus there is also proof that global warming is caused by lack of pirates. And people always find anecdote persuasive; often more persuasive than anything ‘science’ says. But there are good reasons for anecdotal evidence (or hearsay) being excluded from criminal trials as well as science.

Apart from false cause one thing any scientist learns is that the plural of anecdote is anecdotes, not data. That’s why anecdotal ‘evidence’ is not allowed – but how many times have you seen an advertisement first using the appeal to antiquity followed by “used and trusted by millions!” – the inference being ‘so it must work’! The popular media in the UK seem to be entirely devoid of the capacity for critical thought or evaluating evidence which fuels the above. I have ranted in other posts about that awful poo woman or Radio 4 consulting that Aggie ‘How Clean is Your House’ lady on public health and immunology. Essentially the meeja tends to be arts, not science-led and it shows in the quality and depth of science reporting. Let’s be polite and call it a need to represent balance:

So, studio audience, you’ve heard what Prof Three-Brains who has been studying this subject for decades has to say but now let’s talk to Sharon here who has reached completely the opposite conclusion by sitting on her sofa and speculating...

Something else I’ve noticed while researching this topic is that an awful lot of the websites I’ve delved into seem to be selling some sort of alternative to these ‘evil’ vaccines. Funny that…

The Dunning-Kruger Effect

The Dunning-Kruger Effect is a common cognitive bias that leads people to greatly overestimate their skill in a particular area relative to their actual level of competence. They not only underestimate their lack of competence, they tend to believe they are more competent than anyone else, especially an expert. DK has been – unfairly – summarised as being “too stupid to know that they’re stupid” but this is a gross oversimplification. DK manifests itself in several ways. People who are genuinely expert tend to downplay their knowledge or ability and underestimate their skill in comparison with others. They often overestimate others’ ability to understand their field. “Well, it’s really very simple…”

This is counterbalanced by the non-experts who overestimate their skill – to quote Dunning and Kruger “this overestimation occurs, in part, because people who are unskilled in these domains suffer a dual burden: Not only do these people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realise it.” But don’t mistake DK for stupidity. Look at Linus Pauling: two Nobel Prizes and went totally off the rails regarding Vitamin C (elements of the Peter Principle here) or James Watson, co-elucidator of the structure of DNA and now a complete fruitcake. The relevance of DK to the vaccine debate is that people who are unused to critically evaluating scientific data (rather than just reading the abstract) will be less likely to be able to discriminate between Cargo Cult Science, Tooth Fairy Science, a good scientific study or one riven with logical flaws or iffy methodology (such a sampling errors or poor blinding or the other things we look for to pick holes in others’ work!). But they will assume that if they are competent or successful in other areas they are quite capable of making these evaluations. Perhaps this is why it appears that the middle classes supposedly are the least likely to take up MMR – but the data here is sketchy (savour the irony that I’m not adverse to anecdote if it supports my position and I can’t be arsed to find the proper reference!)

People have taken against vaccines ever since Jenner suggested inoculating people with zits scraped off cows’ arses. And so much of the anti-vaccine information out there on the Interwebs looks plausible and persuasive. There are plenty of case studies (anecdotes, not data!) and opinion from all sorts of people who sound like they are well informed. Some are easy to spot: anyone recommending that colloidal silver / Echinacea / vitamins / supplements as being more effective than vaccines etc with a link to buy them is usually a woo merchant. Or promoting the Naturalistic Fallacy. Oprah Winfrey is renowned for her love of alt-med woo and some British TV shows aren’t far behind, apparently (I can’t claim expert knowledge of this as I have to work for a living and so miss daytime TV). But a key differentiator is the use of anecdote. Most diseases are self-limiting (you get better or die) and if getting better coincides with the ‘therapy’ people credit the therapy – this is another fallacy called confirmation bias. This is why men never put the toilet seat down, incidentally. Apart from those who refuse to vaccinate their kids point blank there are those who pick and choose which ones or alter the schedule. The people working in public health who make these decisions are very, very bright people who are expert in their fields and the committees that come up with vaccine schedules or which ‘flu strains to put in next year’s vaccine are the cream of the crop. I am not an expert in immunology but as a microbiologist I have a reasonable working knowledge of the subject and as it’s not far from my comfort zone / dubious expertise I can read the academic literature without fear. I don’t challenge the vaccine schedule but that’s not through blind faith or lack of research on my part – it’s because I haven’t found a single study that’s worth a light that links vaccines with any of the pervasive developmental disorders. Or much else that gives me significant pause for thought when getting my kids (aged one and five) stabbed the day a particular vaccine comes on to the schedule. As I write this my youngest is having his first MMR shot.

So, be informed. Be concerned by all means. Take an interest. But remember: smallpox – history. In the US immunisation has bought death due to vaccine-preventable illness down by 99%. But globally over 2 million kids still die from the vaccine-preventable illnesses that used to kill about 25% of us and that had been all but eradicated in the West.

Until now. 

I think in this case Jorge de Santayana y Borrás had it right – those who fail to learn from history are doomed to repeat it.

 

QR-Code

Thanks for reading this. As well as the sarcastic posts check out the News and the Resources pages. You can also find out more about Rectofossal Ambiguity or contact me with questions.

Print Friendly

6 thoughts on “Measles, the Media and the Dunning-Kruger Effect

  1. Hi, I love your blog and read it enthusiastically. I just have one comment about Linus Pauling. I know he became a household joke following his stance about Vitamin C. I do recall reading some years after he died an article in the New York Times Magazine about some newer research at MIT then was lending some support to his theories about Vitamin C. The premise of the article was that maybe he wasn’t such a joke after all. I don’t remember when I read it or the specific research cited, but it’s something that has stayed with me after many years. Just wanted to mention it.

    • Hello and thank you for the kind words – and for putting up with the glitches and general technical incompetence on my part while I learn how to do this.
      I’m not sure I’d characterise the bloke who’s arguably the greatest expert on the chemical bond – even though he’s dead – as a joke but he did kind of lose it after that second Nobel. Perhaps he should have stuck to his knitting rather than becoming poster boy for the Peter Principle.
      There was a Cochrane review on this if I recall saying that Vit C supplementation might reduce the symptoms of lab-confirmed ‘flu by 12 hours – but that sort of reduction based on patient perception rather than anything empiric when ‘proper’ flu is a two week outing sounds like artefact to me.
      There’s a recent look at the wider Vit C / Pauling legacy here – what I will say for the old boy is that he might have gone native on Vit C but at least he didn’t turn into a xenophobic nutter like James Watson. Getting a Nobel does odd things to scientists.
      My comment on the wider literature on this is that Pauling caused millions to be spent on trying to prove this and didn’t – and every woo peddler on the planet has tried to prove that Vit C cures everything – but despite all the efforts no-one has proved Vit C is effective in curing anything but scurvy. Apart from electronegativity citing LP smacks of the classic appeal to authority fallacy.
      Vitamin D is another matter tho….
      Thanks again.

  2. but….you have to keep in mind, this is the medical industries fault that people are going this route. They have lied to us so many times now, that even if they did do a complete turn around of honesty, people would not believe them anymore anyways, trust is a delicate thing, and that trust has been trashed. So as you know, many people do not have the ability to forgive and forget….Im one of them. It is a shame, but thats what happens in the world of lies and broken promises.

  3. oh, and keep in mind also, your data about our life expectancy is waaaaaaay off, those numbers are “Including” war deaths, back then, populations were very low, and every country, and every culture were hard at work killing each other, there for, soldiers tended to range in ages from 14-25, which of those people in that age group often died sooner than they were suppose to. So now that the populations are higher, and we stopped gathering in fields by the thousands to kill each other……well ya, our life expectancy rate has dramatically increased, we have had only marginal increases in age expectancy. And a Huuuuuuge increase in life expectancy, once we learned to use friggen soap and water, and to stop eating rotten food, to me vaccines have had very little impact on how long we live.

  4. There is an element of truth in what you say, Curtis. Those things certainly are factors in increased longevity. But many immunisable diseases are not particularly susceptible to hand washing, and are spread by means other than impure water. If you look at the causes of death over time, immunisable diseases fall by a lot, lot more than many other causes.

Comments are closed.