You’re bad at evaluating risk
… and so am I
Over millions of years of evolution, our brains have become extremely efficient at responding to perceived risk. The reason why is pretty straightforward — if you were slow to detect and respond to an actual risk, you died. Therefore, you didn’t have a chance to have or raise offspring, so your “too slow” genes died with you. In the evolutionary landscape, there were plenty of different magnitudes and intensities of important-enough risks (“will that animal eat me?”, “will falling from that edge break my leg?”, “will those fast-moving waters sweep me away and drown me?”, “am I going to freeze to death without a fire?”, etc), so we got pretty good at calculating and responding to those threats without even really thinking about it. But there was never much evolutionary mileage in figuring out the difference between two quite small risks: for example, “if I don’t quite clean this fish out well enough before I cook it, I might get an upset stomach, but if I spend longer working with this sharpened tool to clean it more thoroughly there’s a chance that I’ll cut myself and the cut will get infected”.
The problem is that, today, most of the risks our brains are good at estimating and responding to, have largely been controlled or eliminated — exactly because they’re big enough risks not to be considered “acceptable” if uncontrolled. Therefore, the risks we actually deal with now are almost all too small for our brains to be any good at making decisions around them. When scaled population-wide, that deficit can have real and significant consequences. Here’s a simple example: in the years following the September 11 attacks, the increased security measures implemented by the US government’s Transport Security Agency resulted in hundreds or even thousands of additional deaths. In the long run, the death toll almost certainly exceeded the deaths on September 11. But wait — that’s absurd! They may have made people stand in line for hours on end and take off their shoes, and they intimidated people and groped children and humiliated people with disabilities… but they didn’t kill anyone. Except that they did: flying in the US became such a slow and inefficient and painful experience, and the constant, visible obsession with anti-terrorism measures kept reminding people of the (vanishingly tiny) threat of terrorist attack, so hundreds of thousands of people chose to travel by car instead of taking an airline flight. And travelling by car is way more dangerous than travelling by air, so all those extra car trips resulted in a considerable increase in deaths in road accidents. If all of those people had travelled by air instead, at a best estimate none of them would have died (except for the handful who might have been killed in road accidents on their way to or from the airport).
The failures that took place in the above — and led to all those avoidable deaths — are illustrative of our deficits: we consider new and different risks to be far greater than they really are, especially if the potential consequences of said risks are also new and different. And the more visible the negative consequence of something is, again the more we consider the magnitude of the risk to be. The idea of being on a plane that gets hijacked and flown into a building (the footage of which is then broadcast non-stop for weeks) pushes all these buttons — that is exactly how terrorism works. The parts of our brain that determine and react to risk overrate the danger by many, many orders of magnitude. By contrast, road accidents are mundane. They just happen. By the time we’re in early adulthood, most of us know or knew someone who was seriously injured or killed in a road accident… and yet because it’s mundane and familiar, and travelling by road is something most of us do nearly every day, we’ve trained ourselves to live with that risk. And so in practice, we tend to consider the risk to ourselves as negligible (unless we’re specifically asked to think about it… and often, even then). It’s not wrong that we get on with our lives — perhaps while supporting or investing in ongoing improvements in road safety — but when it comes to a choice between the genuinely significant risk and the perceived (but actually insignificant) risk, we take the one that is objectively far, far worse.
But why am I choosing today to talk about how bad we are at considering small risks? It’s topical, of course, and connected with the pandemic. First, a brief thought experiment: let’s say that — by magic — we could distribute a vaccine to everyone on the planet in a single day. Let’s say it happens today. I’m now going to write two headlines for tomorrow’s newspapers:
WHO Confirms Worldwide Vaccination Success
or
150,000 People Dead Within 24 Hours of Receiving COVID Vaccine
The thing is… it’s the headline for exactly the same story. But I bet you didn’t respond to both headlines the same way. Did I hide the truth with the first headline? Is the second headline a lie? Neither. They’re both “true”. But the latter, completely true headline virtually forces your evolved risk-assessing brain to a conclusion that is completely wrong.
So what’s the trick? Many of you will have spotted it already (perhaps you googled it, as I did when I was thinking of this story yesterday) — every day, worldwide, about 150,000 people die. Even armed with this information, that second headline is very difficult to think your way around, thanks to our automatic-thinking brain. Your instinct for assessing threats immediately grasps that 150,000 people dead inside 24 hours associated with any one thing must mean that that one thing is really, super bad. But your instinct for assessing threats is incapable of realising that the connection the headline draws is spurious — the logical fallacy of post hoc ergo propter hoc (since the death followed the vaccine, the death was caused by the vaccine). It is even less capable of integrating and responding appropriately to the knowledge that 150,000 people would have died in that time frame anyway, even once you know the latter to be true.
This is why I am extremely worried by what a number of European countries are doing right now with one of the SARS-CoV-2 vaccines. There have been millions of doses of vaccines administered in these countries, and in the time since those vaccine doses have been administered, there have also been a number of cases of blood clots reported in those same countries, including among people who have received a dose of a vaccine. I’ve tried to write that in a way that minimises the reader’s instinct to causally link the two things, but it’s bloody difficult to do. Our minds are pattern-making machines, even when we don’t want them to be, and as you read the above your mind would have worked very hard to do exactly the thing I didn’t want it to do: to draw the conclusion that the vaccines caused the blood clots. So let me state it to the best of anyone’s knowledge so far: there is no known causal link between the vaccinations and blood clotting. Indeed, the incidence of blood clotting in the number of people vaccinated so far is slightly lower than the expected incidence of blood clotting in that many people in the general population (the variation from normal is not statistically significant — it would be just as wrong to say that we have reason to suspect that the vaccine prevents clotting other than indirectly — see below). But that hasn’t stopped a whole bunch of countries from suspending their vaccination programs using that particular vaccine.
Here’s where it gets far worse: there’s still a global pandemic on. Those countries that have suspended parts of their vaccination programs will, as a direct result of that action, have fewer people vaccinated (certainly in the short term, and possibly ever, if the result is a decrease in public acceptance of COVID vaccines). COVID-19 is still and will continue to be a real threat: it kills about 1% of people who contract it, and leaves about 30% of people who contract it with long-term adverse health effects (such as fatigue, loss of smell and taste, and chronic heart, lung and kidney problems). Even after I remind you of that, your automatic risk-assessing brain is still saying “but what about the blood clots?” Because your risk-assessing brain is captivated by the novelty (and availability, given what you’ve probably seen in the news) of the thromboembolism cases and the countries suspending their vaccination programs (“they must know what they’re doing, right?”). Meanwhile, whether it feels like it or not, you have become accustomed to the threat of COVID-19 itself as a kind of background noise (whether you live in a country like Australia that has done a good job of controlling the pandemic, or a country like the UK which has not). Based on the information to hand so far, the best estimate for increased risk of thromboembolism as a complication of any COVID vaccine is: zero. Not only is the risk of death from any given case of COVID higher than that, but the risk of thromboembolism from COVID-19 infection is actually really high.
What do we do about that? There’s not a great deal we can do directly — our brains work the way they do whether we like them to or not. We’re all pretty much as bad as each other when it comes to instinctive understanding of risk (some may react less, which in turn may give those people a chance to make more considered and better informed decisions, but the innate ability to compare small risks is just as flawed). Even those who analyse and compare risks for a living would be subject to the same flaws of instinctive thinking — they’ll just have a well-developed distrust of those same instincts. Probably the best we can do is actively state and re-state what we understand to be true (to the best of our collective knowledge), and consciously avoid sharing reactions that we know are likely to be flawed.
Short summary? As soon it’s available to you wherever you are, unless you have clear and specific contraindications (e.g. previous anaphylaxis to ingredients present in the vaccine), get the vaccine. Whichever vaccine becomes available to you soonest. All approved vaccines have been found to be very safe and highly effective at preventing severe disease, both in clinical trials and in the hundreds of millions of doses already administered worldwide.
I hope that after a brief hiatus, the various European countries who have reacted they way they have in the past week or so will get themselves back on track. If not, then the very least they could do is send any unused stockpiles of vaccines to countries that they just voted to deny access to cheaper and quicker vaccine production.
